JPH09272481A - Tri-wheeled cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate steering toward a direction with the same phase as the turning direction of the rear wheels have, and to improve turning characteristic and running stability in a turn the traveling by passing the extrapolated line of the rolling axial line of a rolling mechanism for rolling a rear body relating to the front body at the grounding face of a front wheel or its vicinity, resulting in improvement in the steering characteristic and the running stability. SOLUTION: An electric assisted tri-wheeled cycle (written as 'cycle' below) 1 is provided with a rolling mechanism 2 by which a front body and a rear body can relatively roll. An extended line SJ0 on the rolling axis of a rolling mechanism 2 is directed to pass a point G where a front wheel grounds, or the other point near the point G. In this cycle 1, when the line SJ0 is directed to pass the point G, the angle between inclination axis and the rolling axis must intersects is set 0 degree. Then, the rolling axis can not have any angle with respect to the center line in the horizontal plane at the time of turn, so that steering with the same phase as the turning direction of the rear wheels is eliminated, resulting in improvement in the steering characteristic and the traveling stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-wheeled bicycle, and more particularly to a three-wheeled bicycle having improved turning performance and stability during turning.

[0002]

2. Description of the Related Art Conventionally, a three-wheeled bicycle having one front wheel and a pair of left and right rear wheels, and a three-wheeled bicycle having a pair of left and right front wheels and one rear wheel are known. A three-wheeled bicycle that runs with a stepping driving force and an electric motor assisting force is also put to practical use. In a three-wheeled bicycle, in general, in order to prevent one of the pair of left and right rear wheels (or the pair of left and right front wheels) from floating above the road surface when turning, the front body is attached to the rear body. A rocking mechanism for relatively rocking is provided.

Conventional three-wheeled bicycle (one front wheel, two rear wheels)
In the above, the rocking axis of the rocking mechanism is set to be in the front-rear direction and substantially horizontal within a vertical plane including the center line of the vehicle body. 18 to 23 are explanatory diagrams for explaining the mechanical action of the conventional three-wheeled bicycle, and will be described with reference to these diagrams. A swing shaft SJ around which the front body and the rear body of the bicycle rotate relative to each other, a swing reference point R that is an intersection with a vertical plane including the axles of the rear wheels 102 and 103, and a grounding point between the front wheel 101 and the road surface GP. G, tilting axis R connecting the rocking reference point R and the grounding point G
Stand on swing axis SJ from J, ground point G

An intersection Z between the vertical line and the swing axis SJ, ground points P1 and P2 where the left and right rear wheels 102 and 103 contact the ground, and a ground point P
Axle points Q1 and Q2, which are the midpoints Pm between 1 and P2, the intersections of the perpendicular lines standing on the road surface GP from these ground contact points P1 and P2, and the center lines of the axles of the left and right rear wheels 102 and 103, and the center of the bicycle The intersection S between the vertical plane including the line CL and the center line of the axles of the rear wheels 102, 103, the height d of the intersection S from the road surface GP, the wheel base f, the tread length t, the road surface of the rocking reference point R
Height k from GP, e = (k−d), angle α of tilt axis RJ with respect to road surface GP, angle β between tilt axis RJ and rocking axis SJ, and overall center of gravity W. When the lengths of the respective parts are displayed as shown in the figure, the dimensions of the respective parts are as follows.

A length A between the ground contact point G and the swing reference point R, a length B between the swing reference point R and the intersection Z, a height C of the intersection Z with respect to the road surface GP, and an intersection Z from the swing reference point R. Assuming that the horizontal length D up to and the length E of the perpendicular line drawn from the intersection Z to the tilt axis RJ are as follows. A = f / Cos α, B = A × Cos β, C = k + B × Sin (β
−α) Below (β−α)> 0, D = B × Cos (β−α), E
= B × Sin β.

When the ground contact point G is fixed and the intersection point Z is swung when the bicycle is turning to the right, the intersection point Z swings while being restricted by the radius E and the radius B. When viewed from the front, Z draws an almost elliptical orbit and swings to move to a point Z ′. At this time, the following equations are obtained when the movement amounts a, b, and c of the intersection Z in the X axis, Y axis, and Z axis directions are used. Tilt axis RJ
The rotation angle γ of the intersection Z viewed from the direction is γ = Sin ⁻¹ (b /
E), the movement amount F of the intersection Z viewed from the direction of the tilt axis RJ is F =
E (1-Cos γ), a = F × Sin α, c = F × Cos α,
Angle θ of point Z'with respect to the vertical plane including the center line CL
(The angle from the intersection Z to the point Z ′ when viewed from the rear) is θ = Ta
It becomes n ^-1 [b / (C-c)].

The rotation angle λ of the front vehicle body with respect to the rear vehicle body in the swing mechanism 104 is λ = Tan ⁻¹ (H × b) / [B (C−c)] where H = [b ² + (D -A) ² ] ^1/2 The angle δ of the swing shaft SJ with respect to the center line CL on the plan view is δ = Tan ⁻¹ b / (D−a) The rear wheel and the front wheel 101 are equal to the angle δ. By being steered to the same phase side, the ground contact points P1 and P2 move to the points P1 ′ and P2 ′, and the points Q1 and Q2 move to the points Q1 ′ and Q2 ′.

As described above, when the intersection Z moves to the point Z ', the movement amount of the intersection S in the X-axis, Y-axis, and Z-axis directions is h,
Assuming i and j, the result is as follows. Points P1, P2, Q
The tilt angle ε at which the vertical plane formed by 2, Q1 falls against the vertical plane
Is ε = β− Tan ⁻¹ (E × Cos γ / J), J = B × Cos β The moving amount K viewed from the side surface of the intersection S is K = e × Sin ε The moving amount K in this plane direction. The amount of movement of the intersection S is obtained by adding h = e × Cos ε, i = K × Sin δ, j = K × Cos δ The lengths m and n shown in FIG. 21 are as follows. m = f + Sin δ × (t / 2) + j, n = Cos δ × (t /
2) -i

At this time, the equation expressing the line segment connecting the ground point G and the point P2 'on the road surface is Y' = (n / m when the origin of the X ', Y'coordinate system is set at the ground point G. ) X '...
It can be expressed as (1).

Next, let u, v, w be the movement amounts in the X-axis, Y-axis, and Z-axis directions when the total center of gravity W rotates around the tilt axis RJ and moves to the point W '. Using p and s shown in the figure, it is as follows. u = Sin α × N, v = Sin γ × M, w =
Cos α × N L = Tan α × (fs), M = Cos α × (p−L), N
= M (1-Cos γ) The length q in the X direction from the ground contact point G to the point W ′ is q = fs
+ U The stability of the bicycle can be determined from the relationship between Y ′ and v when the length q in the X direction is substituted into X ′ in the equation (1). When Y ′ = (n / m) × q <v, the bicycle is unstable, and when Y ′ = (n / m) × q ≧ v, the bicycle is stable.

For reference, Japanese Examined Patent Publication No. 50-16210.
The publication has one front wheel and a pair of rear wheels, and has one
A three-wheeled bicycle in which a pair of operation knobs is operated to steer the rear wheels through a link mechanism is described. Further, Japanese Patent Application Laid-Open No. 53-17219 discloses a three-wheeled bicycle having a pair of front wheels and one rear wheel, and equipped with a rocking mechanism for connecting the front vehicle body and the rear vehicle body so as to be relatively rockable. Is listed. Also, Japanese Patent Publication No. 61-28528 discloses a steering device for a three-wheeled bicycle having a pair of front wheels and one rear wheel.

[0012]

As described above, in the conventional three-wheeled bicycle, the swing axis of the swing mechanism is set in the front-rear direction and in the substantially horizontal direction. When traveling, when the front wheels are tilted toward the turning side, the angle δ shown in FIGS. 21 and 22 is generated, and the left and right rear wheels are steered by the angle δ to the same phase side as the front wheels. It will turn with a tendency to drift diagonally to. Therefore, the turning feeling is not good,
It is difficult to improve turning performance sufficiently. Further, the stability at the time of turning traveling is reduced, and the rear wheel axle is twisted. The object of the present invention is to eliminate the steering of the rear wheels during turning, to steer the rear wheels to the opposite phase of the front wheels during turning, and to improve the stability during turning.

[0013]

A three-wheeled bicycle according to claim 1 is a three-wheeled bicycle having one front wheel and a pair of left and right rear wheels, and the rear vehicle body is rocked relative to the front vehicle body. The extension line of the swing axis of the swing mechanism to be moved is configured to pass through the grounding point of the front wheel or a portion in the vicinity thereof. Since the angle β explained in the section of the prior art is set to 0, the angle δ explained in the section of the prior art does not occur when turning, and the rear wheels are in phase with the turning direction. It is no longer steered. Therefore, the turning performance during turning is improved, and the running stability is improved.

The three-wheeled bicycle of claim 2 is a three-wheeled bicycle having one front wheel and a pair of left and right rear wheels, and a three-wheeled bicycle having one front wheel and one pair of left and right rear wheels. The intersection point where the extension line of the swing axis of the swing mechanism that swings the rear vehicle body relative to the front vehicle body intersects the road surface is within the range of about 1/2 wheel base from the ground contact point of the front wheels to the rear side. It is configured to enter.

In this case, since the rear wheels are steered to the opposite phase side with respect to the front wheels during turning, as described in the embodiment described later, the turning performance during turning is significantly improved. In addition, the running stability when turning is improved. Here, if the intersection point where the extension line of the swing axis intersects with the road surface is within the range of about 1/2 wheelbase of the rear wheel from the ground contact point of the front wheel, the rear wheel rolls to the opposite phase side. The rudder angle becomes an appropriate size, but if the intersection point where the extension line of the swing axis intersects the road surface is on the rear side of the above range, the steered angle of the rear wheel to the opposite phase side becomes excessive. It is not preferable.

In the three-wheeled bicycle of claim 3, the left and right sides are 1
In a three-wheeled bicycle with a pair of front wheels and one rear wheel,
Since the extension line of the swing axis of the swing mechanism that swings the front vehicle body relative to the rear vehicle body is configured to pass through the grounding point of the rear wheel or a portion in the vicinity thereof, when turning, Even if the front vehicle body swings relative to the rear vehicle body via the swing mechanism, the turning of the front wheels does not occur due to the swinging, so that the turning performance deteriorates. It also improves driving stability.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a three-wheeled bicycle of the present invention will be described below with reference to the drawings. First, the structure of the electrically assisted three-wheeled bicycle 1 will be described. Figure 1
As shown in FIG. 3, an electrically assisted three-wheeled bicycle 1 (hereinafter,
In a bicycle, a swing mechanism 2 for relatively swinging a front vehicle body FB and a rear vehicle body RB is provided, and an extension line SJo of a swing axis line of the swing mechanism 2 connects a ground point G of the front wheel 11 to a ground point G. Oriented to pass. However, an extension of the swing axis
The SJo may be oriented so as to pass near the ground point G.

The front body FB is inserted and supported by the seat tube 3, the head tube 4, the top tube 5, the down tube 6, the rear frame 7, the swing shaft 8 at the rear end, the seat stay 9, and the head tube 4. The handle tube 13, the front fork 10 connected to the lower end of the handle tube 13, and the like. This front body
Front wheel 1 attached to front fork 10 on FB
1, a mudguard 12, a handle 14 at the upper end of a handle tube 13, a saddle 15, a pair of left and right pedals 16, a crank mechanism 17 thereof, a sprocket 18 thereof, a light 1
9, accelerator operating lever and brake operating lever 20a,
20b, a key cylinder mounting portion 21, an operation lamp 22 including a display lamp, a buzzer, switches and keys are mounted. A brake for braking the front wheels 11 is also provided.

The rear vehicle body RB includes a shaft support case 26, a shaft case 27 integrally formed with the shaft support case 26 and having the swing shaft 8 rotatably fitted therein, a rear member 28, and a rear stay 29.
The rear vehicle body RB has a pair of left and right axles 3
0,31, left and right rear wheels 36,37 and their mudguards 36
a, 37a, the battery 32, the electric motor 33, the chain mechanism 34 for transmitting the rotational driving force from the electric motor 33 to the left axle 30 via the clutch mechanism, the shaft support case 26.
A sprocket for stepping drive force input and a speed increasing mechanism incorporated therein, a chain 34 for transmitting a driving force from the sprocket 18 to the sprocket for stepping drive force input, a chain case 35, and the like are attached.

At the end of the left axle 30, the left rear wheel 36
Is non-rotatably attached, and a right rear wheel 37 is rotatably attached to an end of the right axle 31. still,
Although not shown, a manual or electric brake for braking the rear wheels 36, 37 is also provided, and controls the electric motor 33, the lamp 19, electric devices such as an alarm buzzer and switches, and controls charging of the battery 32. A control unit is also provided.

In this bicycle 1, when the clutch mechanism is engaged, the driving force from the pedal 16 and the electric motor 33 are used.
The left axle 30 and the left rear wheel 36 are driven by the driving force from the left rear wheel 37, the right rear wheel 37 is driven to rotate, and when the clutch mechanism is disengaged, the left axle 3 is driven by the driving force from the pedal 16.
0 and the left rear wheel 36 are driven, and the right rear wheel 37 is driven to rotate.

Since the bicycle 1 is characterized by the swing mechanism 2, the operation of the swing mechanism 2 and the bicycle 1 will be described with reference to the contents described in the section of the prior art. Since the extension line SJo of the swing axis of the swing mechanism 2 is oriented so as to pass through the ground contact point G of the front wheel 11,
Since the angle β explained in the section of the prior art is set to 0, the angle δ explained in the section of the prior art does not occur during turning, and the rear wheels roll to the same phase side as the turning direction. No longer being steered. Therefore, the turning performance during turning is improved, and the running stability is improved. In the above embodiment, the case where the present invention is applied to the electrically assisted three-wheeled bicycle 1 has been described as an example, but the present invention can be similarly applied to a manually driven three-wheeled bicycle that is not equipped with the electrically assisted means. Needless to say.

Next, another embodiment in which the above embodiment is partially modified will be described. 1] Other Embodiment 1 ... See FIGS. 4 to 14. In FIGS. 4 to 14, the same components as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 4, in this electrically assisted three-wheeled bicycle 1A, a swing mechanism 2A that relatively swings a front vehicle body FB and a rear vehicle body RB.
Is provided, and an extension line SJA of the swing axis of the swing mechanism 2A is provided.
The point of intersection O, which intersects with the road surface, is configured to fall within a range of about 1/2 wheel base (0.5 × f) from the ground contact point G of the front wheel 11 to the rear side.

The operation of the bicycle 1A will be described. As described in the section of the above-mentioned prior art, FIG.
As shown in FIG. 14, when each point is labeled and the length of each part is displayed as shown in the figure, the length and angle of each part are as follows. A = f / Cos α, B = A × Cos β, C = B × Sin (α +
β) −k D = B × Cos (α + β), E = B × Sin β

As shown in FIG. 13, when turning to the right, the ground point G is fixed as seen from the rear of the bicycle 1A,
When the intersection ZA swings by the angle θ, the intersection ZA is the tilt axis.
The robot moves while being restricted by radius E and radius B with RJ as the center. Therefore, when the intersection ZA when viewed from the front and the side moves along the elliptical trajectory, and the movement amount of the intersection ZA in the Y-axis direction is b, the movement amounts a and c of the intersection ZA in the X and Z directions are: It looks like this: The rotation angle γ of the intersection ZA viewed from the direction of the tilt axis RJ is γ = Sin ⁻¹ (b / E), the tilt axis RJ
The amount of movement F of the intersection ZA viewed from the direction of is F = E (1-Co
s γ), and a = F × Sin β and c = F × Cos β. The inclination angle θ of the intersection ZA in the front view with respect to the vertical plane including the center line CL (the angle from the intersection ZA to the intersection ZA ′ when viewed from behind) is θ = Tan ⁻¹ (b / (C-
c)).

During this right turn traveling, as shown in FIG.
The extension line SJA of the swing axis inclines to the left of the center line CL in plan view, and the axle lines of the left and right rear wheels 36, 37, that is,
The line connecting the ground contact points P1 ′ and P2 ′ of the left and right rear wheels 36 and 37 moves toward the opposite phase of the front wheel 11 by the angle δ. In other words, during turning, the rear wheels 36, 37 are steered to the opposite phase side with respect to the front wheels 11, so that the turning performance is improved, and it is hard to fall and the running stability is improved.

Here, an extension of the swing axis of the swing mechanism 2A
It is desirable that the intersection O where the SJA intersects the road surface be within the range of about 1/2 wheel base (0.5 × f) on the rear side from the ground contact point G of the front wheel 11. That is, when the intersection O is excessively rearward, the rear wheel 3 during turning traveling is
This is because the steered angles of 6 and 37 become excessive and it becomes impossible to secure traveling stability. In the above embodiment, the case where the present invention is applied to the electrically assisted three-wheeled bicycle 1 has been described as an example, but the present invention can be similarly applied to a manually driven three-wheeled bicycle that is not equipped with the electrically assisted means. Is.

2] Another Embodiment 2 ... See FIG. 15 FIGS. 15 to 17 are perspective views of a three-wheeled bicycle 1B according to the present embodiment. The three-wheeled bicycle 1B has a pair of front wheels 4.
A bicycle having 0, 41 and one rear wheel 42 is of a type in which the rear wheel 42 is driven manually, but has an electric assist mechanism that assists the driving of the rear wheel 42 by the driving force of an electric motor. It may be one.

The bicycle 1B has a front vehicle body FB, a rear vehicle body RB, and a swing mechanism 43 capable of relatively swinging the rear vehicle body RB with respect to the front vehicle body FB, and a swing axis line of the swing mechanism 43. The extension line SJB of the rear wheel 42 passes through the grounding point GB of the rear wheel 42. The front vehicle body FB includes a head tube 44, a shaft case 45 integrally formed on a lower rear surface of the head tube 44, a handle shaft 46 rotatably supported by the head tube 44, and a connecting portion 47 at a lower end of the handle shaft 46. It is composed of a wheel support shaft 48 and the like that are fixed to each other. A handle 49 is attached to the upper end of the handle shaft 44, and a pair of front wheels 40, 4 is attached to the left and right ends of the wheel support shaft 48.
1 is rotatably mounted.

The rear vehicle body RB includes a center tube 50, a swing shaft 50a integrally formed at the front end of the center tube 50 and rotatably fitted in the shaft case 45, and a seat integrally connected to the rear end of the center tube 50. Tube 51, center tube 5
The rear frame 52 extends rearward from the rear end of the seat 0, the seat stay 53 connected to the seat tube 51, and the like. A saddle shaft 54a of a saddle 54 is fitted to the seat tube 51 in a positionally adjustable manner.
One rear wheel 42 is attached to the rear end portion of the seat stay 53, and a human-powered drive mechanism 56 that drives the rear wheel 42 via a crank mechanism, its sprocket, and a chain 56a by a pair of left and right pedals 55a and 55b. Is provided.

The bicycle 1B has brakes for braking the front wheels 40 and 41, a brake for braking the rear wheels 42, and these brakes as the handlebar 4 as in a normal bicycle of this type.
An operation force transmission mechanism connected to the brake lever provided in 9.
A light, a buzzer, etc. are also provided, but they are not shown.

Here, an extension line of the swing axis of the swing mechanism 43
Since the SJB is set so as to pass through the ground contact point GB of the rear wheel 42 or a portion in the vicinity thereof, the front vehicle body FB can be used when turning.
Even if the rear vehicle body RB and the rear vehicle body RB relatively swing through the swing mechanism 43, the front wheels 40 and 41 are not steered due to the swing, as in the three-wheeled bicycle 1 in the above embodiment. Therefore, it is possible to prevent the turning performance from deteriorating and the stability during turning is not deteriorated.

[0033]

According to the three-wheel bicycle of claim 1, in the three-wheel bicycle having one front wheel and a pair of left and right rear wheels,
Since the extension line of the swing axis of the swing mechanism that swings the rear vehicle body relative to the front vehicle body is configured to pass through the ground contact point of the front wheel or a portion in the vicinity thereof, description will be made in the section of the prior art. Since the angle β thus set is set to 0, the angle δ described in the section of the prior art does not occur when turning,
The rear wheels are no longer steered to the same phase as the turning direction. Therefore, the turning performance during turning is improved, and the running stability is improved.

In the three-wheel bicycle of claim 2, the three-wheel bicycle having one front wheel and a pair of left and right rear wheels,
The intersection point where the extension line of the swing axis of the swing mechanism that swings the rear vehicle body relative to the front vehicle body intersects the road surface is within the range of about 1/2 wheel base from the ground contact point of the front wheels to the rear side. Since it is configured to enter, since the rear wheels are steered to the opposite phase side to the front wheels during turning, the turning performance during turning is significantly improved, and Driving stability is also improved. Here, since the intersection point where the extension line of the swing axis intersects the road surface is within the range of about 1/2 wheelbase of the rear wheel from the ground contact point of the front wheel, the steering angle of the rear wheel to the opposite phase side Becomes an appropriate size.

A three-wheeled bicycle according to a third aspect is a three-wheeled bicycle having a pair of left and right front wheels and one rear wheel, and a swing mechanism for swinging the front vehicle body relative to the rear vehicle body. Since the extension line of the swing axis passes through the ground contact point of the rear wheels or the vicinity thereof, the front vehicle body sways relatively to the rear vehicle body via the swing mechanism during turning. Even if it moves, the front wheels are not steered due to the rocking as in claim 1, so that the turning performance is not deteriorated and the traveling stability is improved.

[Brief description of drawings]

FIG. 1 is a plan view of a three-wheeled bicycle according to an embodiment of the present invention.

FIG. 2 is a front view of a three-wheeled bicycle.

FIG. 3 is a side view of the three-wheeled bicycle viewed from the inside of the left rear wheel.

FIG. 4 is a view corresponding to FIG. 3 of a three-wheeled bicycle according to another embodiment.

FIG. 5 is a side view for explaining the operation of the bicycle of FIG.

FIG. 6 is a plan view for explaining the operation of the bicycle of FIG.

FIG. 7 is a front view for explaining the operation of the bicycle of FIG.

FIG. 8 is a plan view showing a main part of FIG.

9 is a side view showing the main part of FIG.

FIG. 10 is a front view showing the main part of FIG.

FIG. 11 is a view corresponding to FIG. 8 during turning travel.

FIG. 12 is a view corresponding to FIG. 9 during turning travel.

FIG. 13 is a view corresponding to FIG. 10 at each turning.

FIG. 14 is an explanatory diagram illustrating rotation of an intersection ZA about a tilt axis.

FIG. 15 is a perspective view of a three-wheeled bicycle according to another embodiment.

FIG. 16 is a side view for explaining the operation of the conventional three-wheeled bicycle.

FIG. 17 is a plan view for explaining the operation of the bicycle of FIG.

FIG. 18 is a front view for explaining the operation of the bicycle of FIG.

FIG. 19 is a perspective view of a main part for explaining the operation of the bicycle of FIG.

20 is a plan view of relevant parts for explaining the operation of the bicycle shown in FIG.

FIG. 21 is a side view of the main part for explaining the operation of the bicycle of FIG.

22 is an explanatory diagram illustrating rotation of an intersection Z of the bicycle shown in FIG.

23 is an explanatory side view for explaining movement of the intersection Z of the bicycle shown in FIG.

[Explanation of symbols]

 1, 1A, 1B 3 wheel bicycle 2 Swing mechanism FB Front vehicle body RB Rear vehicle body SJ, SJA Extension line of swing axis G Front wheel grounding point 11 Front wheels 36, 37 Rear wheel O Extension line of swing axis line with road surface Intersecting intersection 43 Swing mechanism SJB Extension line of swing axis GB Ground point of rear wheel

Claims (3)

[Claims] 1. A vehicle having one front wheel and a pair of left and right rear wheels.
In a wheeled bicycle, an extension line of a swing axis of a swing mechanism for swinging a rear vehicle body relative to a front vehicle body is configured to pass through a grounding point of a front wheel or a portion in the vicinity thereof. Three-wheeled bicycle. 2. A vehicle having one front wheel and a pair of left and right rear wheels.
In a wheeled bicycle, the intersection point where the extension line of the swing axis of the swing mechanism that swings the rear vehicle body relative to the front vehicle body intersects the road surface is approximately 1/2 wheel from the grounding point of the front wheels to the rear side. A three-wheeled bicycle characterized by being configured to fall within the range of the base. 3. A pair of left and right front wheels and a rear wheel
In a wheeled bicycle, the extension line of the swing axis of the swing mechanism that swings the front vehicle body relative to the rear vehicle body is configured to pass through the ground contact point of the rear wheel or a portion in the vicinity thereof. A three-wheeled bicycle.