GB2360822A

GB2360822A - Motorcycle with chain derailment gear selecting device

Info

Publication number: GB2360822A
Application number: GB0008013A
Authority: GB
Inventors: Thomas Joseph Orr
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-04-01
Filing date: 2000-04-01
Publication date: 2001-10-03
Also published as: GB0008013D0

Abstract

A motorcycle has engine power transferred to a rear wheel via a sprocket, chain and a gear selecting device comprising a gear cassette arrangement 4, 5, 6 having a freewheel mechanism. Gear selection is achieved by chain derailment and the gear cassette arrangement 4, 5, 6 is modified to have a freely rotating neutral gearcog 5 attached to or positioned beside lowest speed gearcog 6 and chain retention disc 4. A rotating grip control (1, fig 1), which automatically returns to a neutral gear position when not being operated, controls both engine speed and gear selection, the engine speed and gear being matched to give controlled forward acceleration of the motorcycle. The grip control (1) and a brake lever (3) are ergonomically positioned and proportioned such that it is difficult to operate the grip control (1) simultaneously with the brake lever (3). Engine speed may also be increased independently of gear selection to facilitate controlled ascent of steep gradients.

Description

2360822 MOTORCYCLE This invention relates to a motorcycle.

Motorcycles are well known vehicles in which the engine power is translated to the rear wheel via a clutch and gearbox. The speed of a motorcycle engine is controlled by a throttle device, operation of the throttle is achieved commonly by a rotating handlebar grip control. Geared pedal cycles are well known vehicles in which the motive power is translated to the rear wheel via a sprocket, chain and gear cassette with freewheel mechanism. Gear selection in pedal cycles is commonly achieved by chain derailment controlled by wire tension at the derailment device.

Motorcycle clutch and gearbox mechanisms are relatively expensive and throughout the life of the motorcycle require replacement of worn components.

An object of this invention is to provide a motorcycle which does not require a clutch mechanism and the gearbox is replaced with a gear cassette with freewheel mechanism. In this invention gear selection is to be achieved by chain derailment. In this invention the gear cassette is to be modified to have a freely rotating neutral gearcog attached to or positioned beside the gear cassette between lowest speed gearcog and a chain retention disc.

2 A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which; Figure 1 and Figure 2 show the plan and elevation of the rotating grip control 1, throttle control 2 and brake lever 3 at the right hand side of the handlebar; and Figure 3 shows a section through the modified gear cassette identifying the chain retention plate 4, the freely rotating neutral gearcog 5 and the gear cassette 6.

Referring to Figures 1, 2 and 3, when the motorcycle is at rest, the grip control 1 is at the neutral position, the engine runs at tickover speed and the chain is engaged with the neutral gearcog 5. There is no tension in the wire operating the chain derailler device or in the wire operating the engine throttle. Rotation of the grip control 1 by the rider causes wire tension to both throttle and chain derailler device to increase which causes the engine speed to increase and the lowest speed gearcog to be engaged and the motorcycle to move forward. Further rotation of the grip control 1 increases the engine speed, by increased wire tension at the throttle, and causes the motorcycle to accelerate up to a suitable speed where second gear is engaged. Further rotation of the grip control 1 engages third gear then, optionally, fourth gear with the engine speed being increased accordingly to achieve controlled forward acceleration of the motorcycle.

3 It is to be made possible to operate the throttle control 2 independently of gear selection, in order to facilitate controlled ascent of steep gradients by the motorcycle. The grip control 1 and rear brake lever 3 are to be ergonomically sized and positioned relative to each other such that it is made difficult to operate the grip control simultaneously with the rear brake lever. It is to be arranged that when the rear brake is applied the grip control 1 returns to the neutral position by return spring or other means. When the grip control 1 has returned to the neutral position the engine speed returns to tickover speed and the chain engages the neutral gearcog 5.

4

Claims

1. A motorcycle which does not require a clutch mechanism and the gearbox is replaced with a gear cassette 6 and freewheel mechanism, gear selection is to be achieved by chain derailment, the gear cassette arrangement 4, 5 and 6 modified to have a freely rotating neutral gearcog 5 attached to or positioned between lowest speed gearcog and chain retention disc 4.

2. A motorcycle as claimed in claim 1 wherein both gear selection and engine speed are controlled by a rotating grip control mechanism 1 and 2 on the right hand side of the handlebar, with engine speed and gear selection matched to give controlled forward acceleration of the motorcycle.

3. A motorcycle as claimed in claims 1 and 2 wherein means are provided for the automatic return of the grip control 1 to the neutral position when not being operated.

4. A motorcycle as claimed in claims 1, 2 and 3 wherein the grip control and brake lever on the right hand side of the handlebar are ergonomically positioned and proportioned such that it is made difficult to operate the grip control simultaneously with the brake lever.

5. A motorcycle as claimed in claims 1, 2, 3 and 4 wherein it is made possible to increase engine speed independently of gear selection to facilitate controlled ascent of steep gradients.

6. A motorcycle substantially as described herein with reference to Figures 1, 2 and 3 the accompanying drawings.