GB2413538A

GB2413538A - Motorcycle front fork assembly

Info

Publication number: GB2413538A
Application number: GB0506341A
Authority: GB
Inventors: Benjamin John Ridehough
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-04-13
Filing date: 2005-03-30
Publication date: 2005-11-02
Anticipated expiration: 2025-03-30
Also published as: GB0408150D0; GB2413538B; GB0506341D0

Abstract

A facility within a motor cycles upper front fork assembly which will alter the angle relative to the bikes chassis, having a direct effect on the bikes stability and steering sensitivity. The 'top' fork assembly (6 Fig 1) consists of an upper member 12 and a lower member 14, with outer housings 7 and 8, connected by longitudinal tubes 9 and 10. Angular slots (11, Fig 5) contained within the inner faces of the upper housing 12 will provide angular displacement of the top assembly relative to the lower member 14 as a commercial screw (not shown) is turned within the threaded bore (17, Fig 5) causing the dowels (13, Fig 5) to displace the outer housings 7.

Description

241 3538 Variable Geometry to alter the 'Rake' and 'Trail' on motorcycles

and the like.

The invention relates to motorcycles, in particular that of racing bikes and riders who participate in this popular sport.

Each racetrack can vary considerably one to the other by reason of the layout of the landscape that the track was originally designed and instated. By example road track surface convexity, (commonly known as road camber), also that of the 'tracks' bends, which can vary in their radii attitudes.

There would be a significant advantage if the rider or that of a person familiar with the 'race tracks' layouts, and a facility within the 'bikes' construction to easily alter the 'angle' of the 'front' fork assembly, which will have a direct effect on the bikes response by way of stability and turning or steering sensitivity, (commonly known as the 'rake' and trail').

my VV3Y of the following description and drawings the invention seeks to offer this facility, to enable the rider or his technical staff to easily and quickly alter the bikes 'rake' and 'trail' performance attitudes.

Fig 1 Elevation of the upper forks housing.

Fig 2 Elevation of Item 7 Fig 3 Elevation of Item 8 Fig 4 Plan and elevation F'g 5 Plan view in direction of arrow 'X' Item 6 Fig 1 is the 'top' fork assembly (the forks and 'handle-bar' not shown). - 1

- - -

Items 7 and 8 are the outer housings connected by longitudinal tubes, items 9 and 10 (for this description that of high tensile tubing).

Item 7 Figs 1, 4 and 5 is the upper housings for the two forks (not shown) .

Angular slots Items 11 Figs 2 and S contained within the inner faces of the upper housing 12, the length of the arc is deemed by the angular dimension 0 to a designated depth. A circular dowel or stud Item 13 Fig retained within the outer ends of Item 16 locates within the tongue 7A Figs 2 and 5. Further location of the outer housings Items 7 Figs 1, 4 and is achieved by the 'tongue' 7A Fig 4 fitting within a compatible slot 11 Fig 2 (commonly referred to as a mortise and tenon joint).

Finally the assembly of the top housing 12 to the outer housings 7 Figs I, 2 and 5 is secured in positive position by acceptable gripping mechanical fasteners, contained within the slots 18 Figs 4 and 5.

The lower outer housings Items 8 Figs 1 and 3 are secured to the lower inner section Item 14 by means of cotter pins or recognised mechanical fastening means (not shown).

A plan view Fig 5 shows the layout of the top assembly of the 'inner' and outer' members Items 12 and 7.

A pocket Item 15 is located within the member 12 having a compatible circular or square section bar 16 Fig 5 having a threaded portion at the centre.

A commercial screw (not shown) with a thread form compatible with the Breaded bore 17 Fig 5, will permit small angular movement of the top assembly which will cause the front wheel via the forks to be set either fore' or 'aft' of the original neutral position.

The permissible angular displacement of the top housing assembly Item 12, via the outer housings 7 Fig 1 is governed by the difference of the angle variance set between 0 and 8 .

By definition, for this example only the dimension 'C' of 5mm will provide approx. 1-1.5 degrees movement at radius 'R' dimension, of the top' assembly relative to the 'lower' assembly. - 2 l

Finally, all dimensions and material specifications will satisfy the design criteria. - 3

Claims

Claims A mechanical facility for altering tle front fork assembly angle of

motor cycles, consisting of an upper and lower member having outer housings connected by longitudinal tubes' the upper ouster housings having tongue like projections compatible with slots within the inner faces of the top member provides a commonly referred to mortise and tenon joint circular dowels/studs connect the top outer housings to a square section bar located within a compatible pocket at the centre of the 'top member, a threaded bore accommodates a commercial screwlfastener, the tongue and 'groove' sections are radial in their shape and thus enable the top member to have angular displacement relative to the lower member as the commercial type screw (not shown) is moved in' or out of the threaded bore within the square section bar.
2. The lower outer housings as in claim I. Are sectored to the lower member by means of cotter pins or that of mechanical fasteners or the like such that both the outer housings and lower member are an integral unit.
3. A mechanical facility for altering tle front fork assembly angle relative to the cycles framework as claimed in claim I or claim 2 and substantially as herein described with reference to the accompanying drawings.