Note: Descriptions are shown in the official language in which they were submitted.
BICYCLE SUSPENSION WITH A WHEEL LINK IDLER
TECHNICAL FIELD
[0001] The application relates generally to bicycle suspensions and, more
particularly, to
a bicycle rear suspension.
BACKGROUND OF THE ART
[0002] Rear suspension configurations for bicycle, more specifically for off-
road bikes,
such as mountain bikes, downhill bikes, and the like, have various suspension
geometries
and characteristics. Rear suspension configurations affect the bicycle
dynamics during
use, notably traction and maneuverability when riding on rough terrains, for
example. The
approach to develop bicycle suspensions is strenuous and multifactorial.
Characteristics
of the rear suspension, amongst others, may affect the dynamic behavior of the
bicycle
during use. There remains space for improvements in the field of bicycle
suspensions.
SUMMARY
[0003] In one aspect, there is provided a frameset of a bicycle, comprising: a
frame having
a bottom bracket defining a crankset rotational axis, the frame defining a
rear suspension
pivot at a higher elevation than the crankset rotational axis; and a rear
suspension for
suspending a rear wheel of the bicycle, the rear suspension defining a
suspension travel
of the suspended rear wheel relative to the frame, the rear suspension
including a wheel
link, a brake link separate from the wheel link, and a shock linkage, the
wheel link
including a left arm and a right arm extending on opposite sides of the frame,
a proximal
end of the left and right arms being pivotally connected to the rear
suspension pivot of
the frame thereby defining a main fixed pivot axis, the right arm of the wheel
link including
a recessed area at the proximal end thereof, the recessed area defining a flat
surface
that is transversely offset in a vertical plane relative to an adjacent
outwardly facing
surface of the wheel link, the wheel link and the brake link pivotally
connected to each
other via a first floating pivot, the first floating pivot concentric with a
rear wheel rotational
axis, an elevation of the main fixed pivot axis relative to the first floating
pivot
corresponding to between 30% and 125% of the suspension travel when the rear
suspension is in a rest position and unloaded, the shock linkage pivotally
mounted to the
Date Recue/Date Received 2022-01-17
frame at a fixed location thereon, the brake link and the shock linkage
pivotally connected
to each other via a second floating pivot, the wheel link having an idler
pivotally mounted
thereto, the idler being mounted in the recessed area, the idler configured to
intermesh
with an upper chain segment running from a rear wheel sprocket to a chain
ring, the idler
having an idler pivot axis positioned below a projection line extending from
the first
floating pivot to the main fixed pivot axis.
[0004] In another aspect, there is provided a bicycle, comprising: a frame
having a bottom
bracket defining a crankset rotational axis, the frame defining a rear
suspension pivot
located at a higher elevation than the crankset rotational axis; a drive unit
mounted to
the bottom bracket, the drive unit including a crankset drivingly engaged to a
sprocket of
a rear wheel via a chain; a front wheel mounted to the frame via a steerable
front fork; a
rear suspension suspending a rear wheel mounted to the rear suspension via a
rear
wheel axle for rotation about a rear wheel axis, the rear suspension defining
a suspension
travel of the suspended rear wheel relative to the frame, the rear suspension
including: a
wheel link, a brake link separate from the wheel link, and a shock linkage,
the wheel link
including a left arm and a right arm extending on opposite sides of the frame,
a proximal
end of the left and right arms being pivotally connected to the rear
suspension pivot of
the frame thereby defining a main fixed pivot axis, the right arm of the wheel
link including
a recessed area at the proximal end thereof, the recessed area defining a flat
surface
that is transversely offset in a vertical plane relative to an adjacent
outwardly facing
surface of the wheel link, the wheel link and the brake link pivotally
connected to each
other via a first floating pivot, the first floating pivot concentric with the
rear wheel axis,
the wheel link having an idler pivotally mounted thereto, the idler being
mounted in the
recessed area, the idler engaging a chain segment between the sprocket of the
rear
wheel and the crankset, the idler having an idler pivot axis positioned below
a projection
line extending from the first floating pivot to the main fixed pivot axis, an
elevation of the
main fixed pivot axis relative to the first floating pivot corresponding to
between 30% and
125% of the suspension travel when the rear suspension is in a rest position
and
unloaded, the shock linkage pivotally mounted to the frame via a shock linkage
pivot on
the frame, the brake link and the shock linkage pivotally connected to each
other via a
second floating pivot, a shock absorber having a first end pivotally mounted
to the frame
2
Date Recue/Date Received 2022-01-17
at a fixed location thereon and a second end pivotally mounted to the shock
linkage via a
third floating pivot.
DESCRIPTION OF THE DRAWINGS
[0005] Reference is now made to the accompanying figures in which:
2a
Date Recue/Date Received 2022-01-17
[0006] Fig. 1 is a side elevational view of a bicycle on an horizontal plane G-
G
extending along longitudinal axis X-X, the bicycle viewed in a vertical plane
A-A
extending along vertical axis Y-Y, according to an embodiment;
[0007] Fig. 2 is a side elevational view of a frameset of the bicycle shown in
Fig. 1,
according to an embodiment;
[0008] Fig. 3 is a partial perspective view of the frameset shown in Fig. 2,
showing
components of a rear suspension, according to an embodiment;
[0009] Figs. 3A to 3C are magnified exploded views of pivots components on the
frame
of the frameset shown in Fig. 3;
[0010] Fig. 4 is a magnified partial perspective view of components of the
rear
suspension of Fig. 3, when viewed from the rear of the bicycle;
[0011] Fig. 5 is a simplified mesh view of the frameset with the rear
suspension of Figs.
2-4 when the bicycle is unloaded;
[0012] Fig. 6 is a partial perspective view of a frameset with a rear
suspension
according to another embodiment;
[0013] Fig. 6A is a magnified view of a pivot component on the frame of the
frame set
with the rear suspension shown in Fig. 6;
[0014] Fig. 7 is another partial perspective view of the frameset with the
rear
suspension as shown in Fig. 6, with some components hidden to show components
not
observable in Fig. 6; and
[0015] Fig. 8 is a simplified mesh view of the frameset with the rear
suspension of Figs.
6-7 when the bicycle is unloaded.
DETAILED DESCRIPTION
[0016] Fig. 1 illustrates a bicycle 1, in particular an off-road bicycle, also
known as a
mountain bike. The bicycle 1 has two wheels, namely a front wheel 2A and a
rear wheel
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2B. The bicycle includes a drivetrain 3 to convert torque applied by an
external power
source (e.g. a human, electric motor or combination thereof) into motive power
transmitted to the rear wheel 2B against the ground, shown here as horizontal
plane G-
G extending along longitudinal axis X-X. As one possibility, such as shown,
the
drivetrain 3 includes a crankset 4 having a left and a right cranks 4L, 4R
(pedals
mounted to them are omitted on the figures) connected to a chain ring 4C. The
crankset
4 may include more than one chain ring 4C depending on embodiments. In the
embodiment shown, no front derailleur is required as the drivetrain 3 includes
a single
chain ring. The drivetrain 3 includes one or more sprocket 5, which may form
part of a
rear cassette mounted on the rear wheel 2B for rotation about a rear wheel
axis R. The
drivetrain 3 includes a chain 6 looped around portions of the sprocket 5 and
the chain
ring 4C. The chain 6 drivingly engages the sprocket 5 and the chain ring 4C to
transmit
torque exerted on the cranks 4L, 4R to the rear wheel 2B. In some embodiments,
such
as shown, a chain tensioner 7 may be part of the drivetrain 3 and may take up
the
change in tension in the lower chain segment, but this is optional. The rear
derailleur 8
may or may not form part of the drivetrain 3, depending on the embodiments.
[0017] The bicycle 1 includes a frameset 10 and a front fork 10A, which may or
may not
be considered as part of the frameset 10. The front wheel 2A is rotatably
mounted to
the front fork 10A. The front fork 10A includes a front suspension to suspend
the front
wheel 2A, although this is optional. The description of other suspension,
steering and/or
braking components of the front fork 10A is omitted for conciseness.
[0018] With reference to Figs. 2-3, the frameset 10 includes a frame 20 and a
rear
suspension having a wheel link 30, a brake link 40, a shock linkage 50, and a
shock
absorber 60. The rear wheel 2B is mounted to the rear suspension via a wheel
axle
2BA. As shown, components 20 30, 40, 50 and 60 are connected to one another
via
pivots. The wheel link 30 is pivotally connected to the frame 20 at pivot J1.
The wheel
link 30 and the brake link 40 are pivotally connected to each other at pivot
J2. The
brake link 40 and the shock linkage 50 are pivotally connected to each other
at pivot J3.
The shock linkage 50 is pivotally connected to the frame at pivot J4. The
shock
absorber 60 is pivotally connected to the shock linkage 50 at pivot J5 and to
the frame
20 at pivot J6. The pivots J1, J2, J3, J4, J5 and J6 may all extend parallel
to each other,
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that is normal to vertical plane A-A of the bicycle 1, as illustrated.
Interfacing parts of the
components 20 30, 40, 50 and 60 pivotally connected to each other form part of
the
pivots J1, J2, J3, J4, J5 and J6. More detail on the pivots J1, J2, J3, J4, J5
and J6 are
described later.
[0019] Subject to an impact on the rear wheel 2B, for instance at a contact
area and
orientation illustrated by the arrow F in Fig. 1, the rear suspension induces
a rearward
and upward movement of the rear wheel axis R, thereby defining a wheel
trajectory T.
The vertical component of the wheel trajectory T (component of the movement
along
vertical axis Y-Y) defines a suspension travel TY. Over the entire suspension
travel TY,
the rear wheel 2B moves relative to the frame 20. The frame 20, wheel link 30,
brake
link 40, shock linkage 50, and shock absorber 60 move relative to each other
because
of their mutual pivotal interconnections. By interaction of the rear
suspension, the shock
absorber 60 opposes to a positive suspension travel to produce and/or maintain
traction
of the rear wheel 2B on the ground while riding. In one aspect, the rear
suspension
configuration may allow for progressive response (or rate) of the shock
absorber 60
dependent upon the suspension travel. Other aspects that may arise from the
rear
suspension configuration are discussed later.
[0020] Components 20, 30, 40, 50 and 60 and their interaction via the pivots
J1, J2, J3,
J4, J5 and J6 will now be individually described.
[0021] The frame 20 includes a top tube 21, a down tube 22 and a seat tube 23
forming
a generally triangular geometry. The frame 20 may be formed as a monocoque (or
"one-piece") structure, with the top tube 21, the down tube 22 and the seat
tube 23
formed as a single part, as one possibility. This may be made using any
suitable
manufacturing technique, including molding. Tubes 21, 22, 23 may vary in shape
and/or
be made as separate parts then connected together via separate joints (e.g.
adhesively
bonded, welded, fastened, a combination thereof, or otherwise). A bottom
bracket BB is
defined at a junction between the down tube 22 and the seat tube 23. The
bottom
bracket BB defines a pedaling axis, or crankset axis CC. The bottom bracket BB
is
adapted to mount the crankset 4 to the frame 20. The bottom bracket BB is
configured
to receive a shaft of the crankset 4 along the crankset axis. As shown, the
bottom
CA 3075064 2020-03-09
bracket BB is located at the lowest point of the frame 20. When the bicycle 1
lies on a
horizontal ground (plane G-G), the bottom bracket BB is at the lowest
elevation from the
ground when compared, at least, to pivots J1, J3, J4, J5, J6. While pivot J2
may also be
at a higher elevation than crankset axis CC of the bottom bracket BB in some
embodiments, it may be otherwise (i.e. lower) in other embodiments.
[0022] With reference to Fig. 3A, a frame pivot shoulder 24 forms part of the
pivot J1.
The frame pivot shoulder 24 projects transversely outwardly ("outwardly" with
respect to
bicycle 1) from a surrounding surface of the frame 20. The frame pivot
shoulder 24
defines a flat plateau 24A for facing an opposite internal surface of the
proximal end 31
of the wheel link 30. The frame pivot shoulder 24 is hollowed thereby defining
a
transverse hole 24B. The transverse hole 24B receives one or more bearing
supports
24C, which may be roller (e.g. roller, ball, or else) bearings, or bushings,
for instance to
receive a pivot axle 24D (axle or shaft). The pivot axle 24D may be considered
part of
the frame 20 or the wheel link 30. The transverse hole 24B (and/or pivot axle
24D)
defines a pivot axis JP1. The pivot axis JP1 is immovable ("fixed") with
respect to the
frame 20. As discussed later, the pivot axis JP1 defines the main fixed pivot
of the rear
suspension (as opposed to "floating").
[0023] With reference to Fig. 3B, the frame 20 defines a linkage pivot
shoulder 25,
similar to the frame pivot shoulder 24 discussed above. The linkage pivot
shoulder 25
projects transversely outwardly ("outwardly" with respect to bicycle 1) from a
surrounding surface of the frame 20. The linkage pivot shoulder 25 defines a
flat
plateau 25A facing an opposite internal surface of the shock linkage 50. The
linkage
pivot shoulder 25 is hollowed thereby defining a transverse hole 25B. The
transverse
hole 25B receives one or more bearing supports 25C, which may be roller (e.g.
roller,
ball, or else) bearings, or bushings, for instance to receive a pivot axle 25D
(axle or
shaft). The pivot axle 25D may be considered part of the frame 20 or the shock
linkage
50. The transverse hole 25B (and/or pivot axle 25D) defines a pivot axis JP4.
The pivot
axis JP4 is immovable ("fixed") with respect to the frame 20. The shock
linkage 50
pivots about the pivot axis JP4 relative to the frame 20, as further discussed
later.
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[0024] With reference to Fig. 3C, the shock absorber 60 pivots relative to the
frame 20
at pivot J6. The frame 20 defines a shock pivot recess 26A and a flat annular
plateau
26B in the recess 26A at pivot J6. The frame 20 defines an oblong hole
receiving a
bearing support 26C, here in the form of a bushing. The bearing support 26C is
recessed in the shock pivot recess 26A and abuts axially against the plateau
26B. In
the depicted embodiment, the bearing support 26C has a peripheral shape in the
oblong shape of the oblong hole. The bearing support 26C itself defines a hole
to
receive a shock pivot axle 26D. The bearing support 260 may be inserted upside
down
(or "reversed") in the recess 26A, to change the relative position of the hole
receiving
the pivot axle 26D, or change the relative position of pivot J6, with respect
to other fixed
pivots and/or crankset axis CC. This may allow fine-tuning of the suspension
geometry
on the bicycle 1. Such pivot axle 26D pivotally interconnect the shock
absorber 60 and
the frame 20 for rotation about the pivot axis JP6 at pivot J6. As is the case
with pivots
J1 and J3, pivot J6 has a pivot axis JP6 immovable ("fixed") with respect to
the frame
20.
[0025] As shown in Fig. 3, in the depicted embodiment, the wheel link 30
includes a left
and a right arm 30L, 30R extending on opposite sides of the frame 20. The left
and right
arms 30L, 30R are connected to each other via a transverse bridge 30B adjacent
an
axial end 31 of the wheel link 30 which is proximal to the frame 20. In the
depicted
embodiment, the transverse bridge 30B is integral with the left and right arms
30L, 30R,
such that parts 30L, 30R and 30B are formed as a single piece. The left and
right arms
30L, 30R and the transverse bridge 30B straddle the rear wheel 2B when the
rear
wheel 2B is mounted on the rear suspension. While the transverse bridge 30B
may
provide more stiffness to the wheel link 30, some embodiments may not have
such
transverse bridge 30B, such that the left and right arms 30L, 30R of the wheel
link 30
may extend independently from each other. The wheel link 30 has a proximal end
31
and extends rearwardly from the frame 20 to a distal end 32. The spacing W
between
the sections of the left and right arms 30L, 30R that extend on opposite sides
of the rear
wheel 2B is narrower along a proximal section 33A of the wheel link 30, and
such
spacing widens along a distal section 33B of the wheel link 30. The wheel link
30
defines an outward bend 33AB along its length L1 where the proximal section
33A
transitions to the distal section 33B, causing such widening. In the depicted
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CA 3075064 2020-03-09
embodiment, the outward bend 33AB is located at a median length (at a location
between 45% and 55% of length L1) of the wheel link 30. Such widening may
increase
radial stiffness of 30L and 30R, and/or allow more space between the distal
end 32 of
the left and right arms 30L, 30R to receive the rear wheel 2B, sprocket 5
(Fig. 1) and
rear braking system (not shown), including for instance a disc brake and disc
brake
hub, when applicable. The wheel link 30 may include internal passages (guides
and/or
hoses) along at least part of its length to route brake oil or cables to the
rear braking
system, and/or internal cables or electric wires to the rear derailleur 8
(Fig. 1), in the
vicinity of the distal end 32, as one possibility. Such hoses, cables and/or
wires may be
external as well in some embodiments.
[0026] The wheel link 30 is pivotally connected to the frame 20 at pivot J1.
The wheel
link 30 includes bearing supports 34, herein bushings, which may be embedded
in the
wheel link 30 or fitted in pivot holes 34A defined in the wheel link 30 at a
proximal end
31 thereof. Such bearing supports are adapted to receive the pivot axle 24D
extending
transversely therethrough, and through the frame 20 at the frame pivot
shoulder 24.
[0027] In the depicted embodiment, the right arm 30R is on the drive side of
the bicycle
1, in that it is located on the chain ring 4C, sprocket 5 and chain 6 side of
the bicycle 1.
The wheel link 30, in this embodiment the right arm 30R has an idler 35
pivotally
mounted thereto. The idler 35 is a toothed gear, though it may be of other
types, such
as a pulley, for instance. The wheel link 30 includes an idler cover IPC
(shown in Fig. 1
but hidden in the following figures), although this is optional. The idler 35
is configured
to intermesh with an upper segment of the chain 6 that runs from the chain
ring 40 to
the sprocket 5. The idler 35 is mounted on an idler pivot axle 35A extending
from the
wheel link 30. Such idler pivot axle 35A may form part of the wheel link 30,
for instance
by being integral therewith, or pivotally connected to the wheel link 30 via
one or more
bushing supports (embedded into the wheel link 30 or assembled thereto)
similar as
those discussed above.
[0028] The wheel link 30 defines a recessed area 36 at end 31. The recessed
area 36
defines a flat surface that is transversely offset in the vertical plane A-A
relative to an
adjacent outwardly facing surface 37 of the wheel link 30. The idler 35 is
mounted in
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CA 3075064 2020-03-09
such recessed area 36. As such, the transverse position of the idler 35 with
respect to
the frame 20 is such that the plane of rotation of the idler 35 may coincide
with the
plane of rotation of the chain ring 40 (or one of the chain rings). This may
improve
alignment of the upper segment of the chain 6 between the idler 35 and the
chain ring
4C, which in turn may improve engagement of the chain 6 on the chain ring 4C.
Additionally or alternatively, having the recessed area 36 may allow a better
transverse
alignment of the idler 35 with the sprocket 5. For instance, the recessed area
36 may be
adapted such that the plane of rotation of the idler 35 may coincide with the
plane of
rotation of the sprocket 5 (or at least one sprocket of the cassette, where
applicable).
[0029] The idler 35 pivots about an idler pivot axis 35B that remains at a
fixed distance
from pivots J1, J2. The idler 35 is not mounted on an intermediary linkage,
hence it
remains fixed (i.e. idler axis 35B does not move) with respect to the wheel
link 30,
irrespective of the suspension travel position. Since the idler 35 is mounted
to the wheel
link 30, movement of the wheel link 30 with respect to the frame 20 about
pivot J1
results in a corresponding movement of the idler 35 with respect to the frame
20.
Having the idler 35 mounted on the wheel link 30 and not on an intermediary
linkage or
structure limits movable pieces, which may save weight, and/or this may allow
a
constant (or near constant) chain load impact on the suspension movement over
the
entire suspension travel, which may not happen when the idler 35 is fixed on
the frame
20 or an intermediary linkage, for instance.
[0030] The idler axis 35B is located lower than pivot J1 with respect to the
vertical axis
Y-Y when the suspension is uncompressed (when the bicycle 1 is at rest and
unloaded). The idler axis 35B is positioned below a projection line extending
from pivot
J2 (from its pivot axis JP2) to the pivot axis JP3. In some embodiments, the
idler axis
35B remains lower than pivot J1 with respect to the vertical axis Y-Y over the
entire
suspension travel TY. The idler axis 35B may be positioned fore or aft the
pivot axis
JP1 with respect to the longitudinal axis X-X, depending on the embodiments.
The
position of the idler 35 may differ depending on its size / diameter. In a
particular
embodiment, the idler 35 may have a pitch circle diameter of 70 mm 3 mm.
This may
allow a better load distribution and/or flexion ratio on the chain 6. In an
embodiment, the
idler 35 is positioned relative to the pivot J1 (positioned, or positioned and
sized) such
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that the chain line of the upper segment of the chain 6 that intermeshes with
the idler
35, or the chain line tangent of the idler 35 extends above the pivot axis
JP1. In a
particular embodiment, the chain line of the upper segment of the chain 6 that
intermeshes with the idler 35 extends 6 mm 2 mm 0.2362 0.0787 inches)
above
the pivot axis JP1 when the bicycle 1 is at rest and unloaded.
[0031] In other embodiments, the pitch circle diameter of the idler 35 may
intersect with
the pivot axis JP1. The chain line of the upper segment of the chain 6 that
intermeshes
with the idler 35 may intersect with the pivot axis JP1. In other words, the
idler 35 may
have a chain line tangent that intersects the pivot axis JP1. This may limit
the pedal
kickback and/or variations of chain tension dependent upon the suspension
travel
position. Because of the particular geometry of the rear suspension, including
the high
position of the pivot J1 with respect to the bottom bracket BB, the idler 35
may allow
greater chain-ground clearance. The idler 35 may allow independent orientation
of the
chain load relative to the chain ring 4C dimension.
[0032] The wheel link 30 rotatably supports the rear wheel 2B at the distal
end 32.
Referring to Fig. 4, the wheel link 30 defines a hole 38 at the end 32. Such
hole 38
extends through both the left and right arms 30L, 30R at the end 32. Such hole
38 (or
holes) receives bearing supports 34 similar to that at pivot J1 (as discussed
above). Left
and right dropout pivot shafts 38L, 38R are mounted to said bearing supports
34. The
left and right dropout pivot shafts 38L, 38R interface with the brake link 40.
The distal
end 42 of the brake link 40 is pivotally connected to the distal end 32 of the
wheel link
30 via the left and right dropout pivot shafts 38L, 38R. Components 38, 38L,
38R form
part of pivot J2. These components 38, 38L, 38R pivotally interconnect the
wheel link
30 to the brake link 40, thereby allowing relative pivotal movement one with
respect to
the other about pivot J2. The pivot J2 is a floating pivot of the rear
suspension, as it
may move relative to the main pivot J1 of the rear suspension on the frame 20,
or
stated differently, it may move relative to the frame 20. The left and right
dropout pivot
shafts 38L, 38R are adapted to mount the rear wheel axle 2BA to the rear
suspension.
The pivot J2, in its role of floating pivot, is concentric with the rear wheel
axle 2BA. In
other words, the rear wheel axis R coincides with the pivot axis JP2 of the
pivot J2.
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[0033] In the depicted embodiment, the brake link 40 includes a left and a
right arms
40L, 40R extending on opposite sides of the frame 20. The left and right arms
40L, 40R
are connected to each other via a transverse bridge 40B adjacent the axial end
41 of
the brake link 40 which is proximal to the frame 20. In the depicted
embodiment, the
transverse bridge 40B is integral with the left and right arms 40L, 40R, such
that parts
40L, 40R and 40B are formed as a single piece. The left and right arms 40L,
40R and
the transverse bridge 40B straddle the rear wheel 2B when the rear wheel 2B is
mounted on the rear suspension. While the transverse bridge 40B may provide
more
stiffness to the brake link 40, some embodiments may not have such transverse
bridge
40B, such that the left and right arms 40L, 40R of the brake link 40 may
extend
independently from each other. The brake link 40 extends rearvvardly from the
frame
20, from the proximal end 41 to an opposite end 42. The brake link 40 defines
a hole 48
at the distal end 42, similar to hole 38 of the wheel link 30, to engage the
rear wheel
axle 2BA. In the depicted embodiment, portions of the left and right dropout
pivot shafts
38L, 38R extend through the hole 48. The hole 48 may receive bearing supports,
such
as hole 38 of the wheel link 30, in addition to or instead of having such
bearing supports
in the hole 38 of the wheel link 30, depending on the embodiments. In other
embodiments, the bearing supports at ends 32, 42 may be flexible mounts, such
as a
bushing, made at least in part of (at least in part of or entirely of) a
resilient material,
such as elastomeric material (e.g. rubber); interconnecting the ends 32, 42 of
the wheel
link 30 and brake link 40. For instance, such resilient mount may be mounted
in hole 38
and/or hole 48 and interface with left and right dropout pivot shafts 38L,
38R. By
deforming, for instance compression and/or torsion, such resilient mount may
allow
relative movement of ends 32, 42. The resilient mount may be adhered to or
mechanically interlocked with the ends 32, 42 and/or left and right dropout
pivot shafts
38L, 38R, for instance. In some cases, such resilient mounting may be more
desirable
than roller/ball bearings, in that they may be more robust against dust and
dirt.
[0034] In the depicted embodiment, the distal end 42 of the brake link 40 is
transversely inwardly offset with respect to the distal end 32 of the wheel
link 30. The
end 42 of the brake link 40 is thus closer to the rear wheel 2B plane of
rotation than the
end 32 of the wheel link 30. The relative position of ends 32, 42 of the wheel
link 30 and
the brake link 40 may be inverted in other embodiments.
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[0035] In the depicted embodiment, the brake link 40 is disposed above (at a
higher
elevation from the ground than) the wheel link 30. The brake link 40 may
support
components of the rear braking system. As shown, the brake link 40, herein the
left arm
40L has bracket anchors 43 embedded in the body of the brake link 40. The
bracket
anchors 43 extend upwardly from a top surface of the brake link 40. Such
bracket
anchors 43 may connect to a bracket or directly to a brake caliper, for
instance.
Although unconventional, the rear brake system and the drivetrain 3 may be
inversely
disposed with respect to the wheel 2B, such that the brake system may be on
the right
side of the bicycle 1 and the sprocket 5 on the left side of the bicycle 1.
[0036] Returning to Figs. 2 and 3, the brake link 40 is pivotally connected to
the shock
linkage 50 at pivot J3. Parts of the brake link 40 and of the shock linkage 50
form part
the pivot J3. In the depicted embodiment, the brake link 40 includes bearing
supports
44 herein roller bearings, fitted in pivot holes 44A defined in the brake link
40 at a
proximal end 41 thereof. Such bearing supports are adapted to receive a male
pivot
axle 44B, herein a fastener, extending transversely therethrough. These
components
44, 44A, 44B form part of the pivot J3. Components 44, 44A, 44B pivotally
interconnect
the brake link 40 to the shock linkage 50, thereby allowing relative pivotal
movement of
one with respect to the other about pivot J3. The pivot J3 is a floating
pivot, as it may
move relative to the frame 20, hence move relative to the main pivot J1 of the
rear
suspension on the frame 20. The pivot J3 has a pivot axis JP3 about which the
brake
link 40 and the shock linkage 50 pivot with respect to each other. Components
44, 44B
can be considered as parts of the brake link 40 or parts of the shock linkage
50. The
shock linkage 50 may include bearings supports forming parts of the pivot J3,
in
addition to or instead of the bearing supports 44 of the brake link 40.
[0037] In the depicted embodiment, the shock linkage 50 includes a left and a
right
member 50L, 50R disposed on opposite sides of the frame 20. The left and right
members 50L, 50R are separate parts, though they may be connected to each
other to
form a single piece. The members 50L and 50R are pivotally connected to the
left and
right arms 40L, 40R of the brake link 40, respectively. In the depicted
embodiments, the
members 50L, 50R defines a triangular structure linking pivots J3, J4 and J5
together.
In the depicted embodiment, the members 50L, 50R each have three segments 51A,
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CA 3075064 2020-03-09
51B, 510 extending between respective pivots J3, J4, J5. The segments 51A,
51B, 51C
form rigid members holding the pivots J3, J4 and J5 at fixed distance from
each other.
The members 50L, 50R may have more or less segments in other embodiments,
depending on the geometry of the shock linkage 50. The shock linkage 50 is
pivotally
connected to one axial end 61 of the shock absorber 60. Parts of the shock
linkage 50
form part of the pivot J5 and interface with the axial end 61 of the shock
absorber 60
(Fig. 2). The connection between the shock linkage 50 and the shock absorber
60 may
include similar features than that of pivot J3, for instance, and thus are not
repeated
herein. Pivot J5 is a floating pivot, for similar reasons as pivot J3
discussed above.
[0038] Turning now to the shock absorber 60, such shock absorber 60 may be of
any
suitable types, including, but not limited to, a fluid damper, spring, or a
combination
thereof. A first axial end 61 of the shock absorber 60 pivotally connect to
the shock
linkage 50 as discussed above, while the opposite axial end 62 of the shock
absorber
60 is pivotally connected to the frame 20 at pivot J6. The shock absorber 60
may have
different sizes and/or dimensions, and/or may be connected to the frame 20 at
various
locations depending on the embodiments. The orientation and/or position with
respect
to the frame 20 may change depending the configurations of the rear
suspension, The
shock absorber 60 pivotally connected to the shock linkage 50 and indirectly
pivotally
connected to other parts of the rear suspension moves angularly with respect
to the
frame 20 while the rear wheel 2B moves along its trajectory T.
[0039] Relative positions of the pivot J1 to J6 may impact the behavior of the
rear
suspension, hence the dynamic behavior of the bicycle 1. Referring to Fig. 5,
a
simplified mesh view of the franneset 10 is shown.
[0040] In operation, the rear wheel axis 2BA may move along its trajectory T,
which
causes a rotation of pivot J2 around pivot J1. Such movement induces a pivotal
movement in pivot J2, which in turn induces a rotation and translation of the
brake link
40 with respect to the frame 20. Movement of the brake link 40 induces a
movement of
pivot J3 relative to the frame 20. The proximal end 41 of the brake link 40
pivots relative
to the shock linkage 50 at pivot J3. The pivot J3 rotates and translates via
forces
induced by the brake link 40 to the shock linkage 50. The shock linkage 50
pivots about
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pivot J4 on the frame 20, which moves pivot J5 in a clockwise direction (with
reference
to Fig. 5). Compression load is taken by the shock absorber 60, which is
compressed
between pivot J5 on the shock linkage 50 and pivot J6 on the frame 20 while
opposing
to such load. When the compression load due to weight of the user on the
bicycle 1
and/or impact load on the rear wheel 2B reduces or is released, all these
interactions
happen reversely (movement of the pivots in the opposite direction than as
described
above).
[0041] Over the entire suspension travel TY, pivot J3 rotates about pivot J4
at a
distance D34 thereof. Pivot J3 has an arcuate trajectory, which consequently
imparts a
horizontal displacement along direction X-X and a vertical displacement along
direction
Y-Y of the proximal end 41 of the brake link 40. A variation of angle between
the brake
link 40 and the segment 51A of the shock linkage 50 that extends between
pivots J3
and J4 occurs. Concurrently, a variation of angle 9 at pivot J2 between a
projection line
passing by pivots J1 and J2 (along the wheel link 30) and a projection line
passing by
pivots J2 and J3 (along the brake link 40) occurs. In a particular embodiment,
the
variation ("delta") of angle 0 over the entire suspension travel TY is 5 T
(increasing
angle over the entire suspension travel TY). Such variation of angle 0 may be
greater in
other embodiments where the vertical displacement of pivot J3 is increased,
depending
on the geometry of the rear suspension. The arcuate trajectory of pivot J3
over the
entire suspension travel TY and the pivotal connection between the wheel link
30 and
the brake link 40 provides for such variation. Such variation of angle 0 at
pivot J2 may
allow for better decoupling the braking forces and the forces transmitted to
the shock
absorber 60 over the entire suspension travel, hence it may provide more anti-
rise
effect at braking.
[0042] The rear suspension may be defined by the relative position of pivots
J1 to J4
and the pivotally interconnected links 30, 40, 51A forming parts of the rear
suspension.
The rear suspension has an instant centre of rotation (or simply "Instant
Centre") that
moves relative to pivot J1 (or other fixed points on the frame 20) as the rear
wheel 2B
travels along its trajectory T. The Instant Centre is defined by an
intersection point
between a projection line passing by pivot J1 and J2 (line along the wheel
link 30) and a
projection line passing by pivots J3 and J4 (line along segment 51A). Such
Instant
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=
Centre moves along an Instant Centre trajectory over the suspension travel TY.
In the
depicted embodiment, over the suspension travel TY, the Instant Centre moves
toward
pivot J1. In the depicted embodiment, the Instant Centre moves toward pivot J1
without
moving rearwardly beyond pivot J1. In the depicted embodiment, the position of
the
Instant Centre remains at an elevation ICx1 ?. than the elevation El' of pivot
J1 over the
entire suspension travel TY. The Instant Centre trajectory is shown at Fig. 5
in broken
line. Other embodiments of the rear suspension may have different Instant
Centre
trajectory, though the one shown is representative of the embodiment shown in
Figs. 2-
4.
[0043] As shown, the pivot J1 is located above the crankset rotational axis
CC, i.e. at a
higher elevation. Also shown, the pivot J1 is located at a higher elevation
than the pivot
J2 when the bicycle is in an unloaded state (bicycle 1 is at rest, without
external loads
applied to it). The elevation El of the pivot J1 relative to the pivot J2 may
correspond to
between 30% and 125% of the suspension travel TY (or "total available vertical
rear
wheel displacement"), where El is taken with the suspension in an uncompressed
state
(when the bicycle 1 is at rest and unloaded). This may correspond to an
elevation El
between 75 mm
2,95 inches) and 250 mm (,=, 9,84 inches). In the depicted
embodiment, the elevation El of the pivot J1 relative to the pivot J2
corresponds to
95% of the suspension travel TY. In such case, a ratio of the rearward
horizontal
component TX of the trajectory T the wheel axis BA over the suspension travel
TY of
the rear wheel 2B is 13% 5%.
[0044] In the depicted embodiment, the pivot J4 is position above (at a higher
elevation
than) the pivot J1. The pivot J4 may be positioned below pivot J1 in other
embodiments,
such as discussed later. Pivot J1 is positioned rearward relative to pivot J4,
along the
longitudinal axis X-X of the bicycle 1. The relative distances between pivots
J3, J4 and
J5 may influence the leverage ratio and/or the progressivity in damping and/or
stiffness
of the rear suspension. In an embodiment, a ratio of a distance D45 between
pivot J4
and J5, and a distance D34 between pivot J3 and J4 (D45/D34) has a value
between
1:1 and 1.5:1. In the depicted embodiment, a distance between pivot J3 and J4,
and a
distance between pivot J4 and J5 are the same ( 5%). In a particular
embodiment, the
ratio of the distance D45 over the distance D34 is 1.2:1.
CA 3075064 2020-03-09
[0045] Referring to Figs. 6, 6A, and 7, another embodiment of the frameset 10
and rear
suspension is illustrated. The like components with the embodiment of Figs. 1-
5 are
identified with corresponding reference numbers in the 100's. The reader can
refer to
corresponding components above for more detail on how the rear suspension
operates.
[0046] In this embodiment, the rear suspension includes pivots J1 to J6 as
described
above, and it operates similarly. The frame 120 includes top tube 121, down
tube 122,
seat tube 123, frame pivot shoulder, flat plateau, transverse hole, bearing
supports, and
pivot axle, similar to that described above, thus not identified on Figs. 6-7
and described
in detail again. While the frame 120 includes a linkage pivot shoulder 125
with flat
plateau 125A, transverse hole 125B, bearing supports 125C and pivot axle 125D,
which
form part of pivot J4 similar to that described above, some differences are
now pointed
out.
[0047] The seat tube 123 of the frame 120 defines an opening 123A to receive
at least
part of the shock linkage 150. In other words, the seat tube 123 at least
partially houses
the shock linkage 150. The seat tube 123 defines a left and a right side
segments 123L,
123R transversely spaced apart from each other, with the opening 123A defined
in
between them. With reference to Fig. 6A, showing a magnified zone of the seat
tube
123 with some components hidden for viewing, the linkage pivot shoulder 125
projects
transversely inwardly with respect to the frame 120, from opposite internal
surfaces
123B of the segments 123L, 123R. Although only 123L shown, it should be
understood
that 123R is arranged similarly at the opposite side. Flat plateaus 125A on
the side
segments 123L, 123R face each other. The shock linkage 150 is disposed inside
the
opening 123A. The shock linkage 150 is pivotally mounted between the opposite
flat
plateau 125A of the left and right segment 123L, 123R. Other aspects of the
shock
linkage 150 are described later.
[0048] The rear suspension includes a wheel link 130, a brake link 140, a
shock linkage
150 and a shock absorber 160. These components 130, 140, 150 and 160 are
pivotally
connected together, as described above in connection with Figs. 1-5. The wheel
link
130 includes left and right arms 130L, 130R, and a transverse bridge 130B,
though
bridge 130B is optional, as described above. Similarly, the brake link 140
includes left
16
CA 3075064 2020-03-09
and right arms 140L, 140R, and a transverse bridge 140B. The wheel link 130 is
pivotally connected to the frame at pivot J1, which defines the main pivot of
the rear
suspension. The wheel link 130 and the brake link 140 are pivotally connected
to each
other at pivot J2, with such pivot J2 coinciding with the rear wheel axle 2BA.
In the
depicted embodiment, left and right dropout pivot shafts 138L, 138R
interconnect the
wheel link 130 and the brake link 140, and form part of pivot J2. The wheel
link 130
includes an idler 135 pivotally mounted thereto, as in Figs. 1-5. Relative
position
between idler 135 and idler pivot axis 135B relative to pivot J1 correspond to
what is
described above, so they are not repeated for conciseness.
[0049] In the depicted embodiment, the wheel link 130 and the brake link 140
are
inverted with respect to each other. In other words, the wheel link 130
extends above
the brake link 140. Stated differently, the wheel link 130 extends at a higher
elevation
than the brake link 140. In the depicted embodiment, the shock linkage 150 is
disposed
between the wheel link 130 and the brake link 140 along the vertical axis Y-Y.
As
shown, pivot J4 is positioned between pivot J1 and pivot J3 along the vertical
axis Y-Y,
with pivot J3 being the closest pivot relative to the bottom bracket BB.
[0050] Fig. 7 shows the same embodiment than Fig. 6, though some components
are
hidden to better show the shock linkage 150. Parts of the shock linkage 150
form part of
the pivot J3, J4 and J5, as described above. In the depicted embodiment, the
shock
linkage 150 does not have left and right members as members 50L, 50R described
above. The shock linkage 150 defines a body 150B, herein a one-piece body,
pivotally
connected to the left and right arms 140L, 140R of the brake link 140. The
shock
linkage 150 includes segments 151A, 151B extending between respective pivots
J3, J4,
J5. The segments 151A, 151B form rigid members holding the pivots J3, J4 and
J5 at
fixed distance from each other. Pivots J3 and J5 are floating pivots. The
shock linkage
150 includes a floating segment 151F pivotally connected to segment 151A at
pivot J5.
The floating segment 151F interconnects the shock linkage body 150B to the
shock
absorber 160. The floating segment 151F is an intermediary part between the
shock
linkage body 150B and the shock absorber 160.
17
CA 3075064 2020-03-09
[0051] The shock absorber 160 is pivotally connected to the shock linkage body
150B
via the floating segment 151F, and pivotally connected to the frame 120 at
pivot J6. The
shock absorber 160 is pivotally mounted to the frame 120 via a bracket 122A of
the
down tube 122. In this embodiment, the bracket 122A is integral with the down
tube
122, though it may be a separate part in other embodiment (e.g. welded,
fastened, or
otherwise connected to the down tube 122). In the depicted embodiment, the
shock
absorber 160 is oriented differently than that shown in the embodiment of
Figs. 1-5
relative to the frame 120. In the depicted embodiment, pivot J6 is at a higher
elevation
with respect to all other pivots J1 to J5 when the rear suspension is
uncompressed/unloaded. This is shown in Fig. 8.
[0052] Referring to Fig. 8, a simplified mesh view of the frameset 10 is shown
with the
geometry of the rear suspension of Figs. 6-7.
[0053] In operation, the rear wheel axis 2BA moves along its trajectory T,
which causes
a rotation of pivot J2 and rear wheel axis 2BA around pivot J1. Such movement
induces
a pivotal movement in pivot J2, which in turn induces a rotation and
translation of the
brake link 140 with respect to the frame 120. Movement of the brake link 140
induces a
movement of pivot J3 relative to the frame 120. The proximal end 141 of the
brake link
140 pivots relative to the shock linkage 150 at pivot J3. The pivot J3 rotates
and
translates via forces induced by the brake link 140 to the shock linkage 150.
The shock
linkage 150 pivots about pivot J4 on the frame 120, which moves pivot J5 in a
clockwise
direction (with reference to Fig. 8). Compression load is taken by the shock
absorber
160, which is compressed between pivot J5 on the shock linkage 150 and pivot
J6 on
the frame 120 while opposing to such load. When the compression load due to
weight
of the user on the bicycle 1 and/or impact load on the rear wheel 2B reduces
or is
released, all these interactions happen reversely (movement of the pivots in
the
opposite direction than as described above).
[0054] Over the entire suspension travel TY, pivot J3 rotates about pivot J4
at a
distance D34 thereof. Pivot J3 has an arcuate trajectory, which consequently
imparts a
horizontal displacement along direction X-X and a vertical displacement along
direction
Y-Y of the proximal end 141 of the brake link 140. A variation of angle
between the
18
CA 3075064 2020-03-09
brake link 140 and the segment 151A of the shock linkage 150 that extends
between
pivots J3 and J4 occurs. Concurrently, a variation of angle 0 at pivot J2
between a
projection line passing by pivots J1 and J2 (along the wheel link 130) and a
projection
line passing by pivots J2 and J3 (along the brake link 140) occurs. In a
particular
embodiment, the variation ("delta") of angle 0 over the entire suspension
travel TY is
100 50 (decreasing angle over the entire suspension travel TY). Such
variation of
angle 0 may be greater in other embodiments where the vertical displacement of
pivot
J3 is increased, depending on the geometry of the rear suspension. The arcuate
trajectory of pivot J3 over the entire suspension travel TY and the pivotal
connection
between the wheel link 130 and the brake link 140 provides for such variation.
Such
variation of angle 0 at pivot J2 may allow for better decoupling the braking
forces and
the forces transmitted to the shock absorber 160 over the entire suspension
travel,
hence it may provide more anti-rise effect at braking.
[0055] The rear suspension geometry may be defined by the relative position of
pivots
J1 to J4 and the pivotally interconnected links 130, 140, 151A forming parts
of the rear
suspension. The rear suspension geometry has an Instant Centre that moves
relative to
pivot J1 (or other fixed points on the frame 20) as the rear wheel 2B travels
along its
trajectory T The Instant Centre is defined by an intersection point between a
projection
of the wheel link 130 and a projection segment 151A interconnecting pivots J3
and J4.
Such Instant Centre moves along an Instant Centre trajectory over the
suspension
travel TY. In the depicted embodiment, over the suspension travel TY, the
Instant
Centre moves away from pivot J1, toward the front of the bicycle 1. In the
depicted
embodiment, the position of the Instant Centre is at an elevation ICx1 ?. than
the
elevation of pivot J1 when the rear suspension is at the rest position and
unloaded, and
the position of the Instant Centre transitions to an elevation ICx1 < than the
elevation
El' of pivot J1 while reaching the total available vertical rear wheel
displacement. When
the rear suspension reaches the total available vertical rear wheel
displacement, the
position of the Instant Centre is at an elevation ICX1 between the elevation
El' of pivot
J1 and the elevation of pivot J4 relative to the crankset rotational axis CC.
The Instant
Centre trajectory is shown at Fig. 8 in broken line. Other embodiments of the
rear
suspension may have different Instant Centre trajectory, though the one shown
is
representative of the embodiment shown in Figs. 6-7.
19
CA 3075064 2020-03-09
[0056] As shown, the pivot J1 is located above the bottom bracket BB, i.e. at
a higher
elevation. Also shown, the pivot J1 is located at a higher elevation than the
pivot J2
when the bicycle 1 is in an unloaded state (bicycle us at rest, without
external loads
applied to it). The elevation El of the pivot J1 relative to the pivot J2 may
correspond to
between 30% and 125% of the suspension travel TY (or "total available vertical
rear
wheel displacement"), where El is taken with the suspension in an uncompressed
state
(when the bicycle 1 is at rest and unloaded). This may correspond to an
elevation El
between 75 mm (v--= 2,95 inches) and 250 mm
9,84 inches). In the depicted
embodiment, the elevation El of the pivot J1 relative to the pivot J2
corresponds to
75% 5 of the suspension travel TY.. In such case, a ratio of the rearward
horizontal
component TX of the trajectory T the wheel axis BA over the suspension travel
TY of
the rear wheel 2B is 13% 5%.
[0057] In the depicted embodiment, the pivot J4 is position below (at a lower
elevation
than) the pivot J1. Pivot J1 is positioned forward relative to pivot J4, along
the
longitudinal axis X-X of the bicycle 1.
[0058] The relative distances between pivots J3, J4 and J5 may influence the
leverage
ratio and/or the progressivity in damping and/or stiffness of the rear
suspension. In an
embodiment, a ratio of a distance D45 between pivot J4 and J5, and a distance
D34
between pivot J3 and J4 (D45/D34) has a value between 1:1 and 1.5:1. In the
depicted
embodiment, a distance between pivot J3 and J4, and a distance between pivot
J4 and
J5 are the same ( 5%). In a particular embodiment, the ratio of the distance
D45 over
the distance D34 is 1.2:1.
[0059] The embodiments described in this document provide non-limiting
examples of
possible implementations of the present technology. Upon review of the present
disclosure, a person of ordinary skill in the art will recognize that changes
may be made
to the embodiments described herein without departing from the scope of the
present
technology. Yet further modifications could be implemented by a person of
ordinary skill
in the art in view of the present disclosure, which modifications would be
within the
scope of the present technology.
CA 3075064 2020-03-09
