GB2283948A

GB2283948A - Cycle handlebar stem with provision for secondary handlebars

Info

Publication number: GB2283948A
Application number: GB9323510A
Authority: GB
Inventors: Paul Buckley
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-11-15
Filing date: 1993-11-15
Publication date: 1995-05-24
Also published as: GB9323510D0

Abstract

The stem is secured to the fork tube 3 of the cycle fork and includes provision 5 for mounting conventional cycle handlebars 6 in a conventional position. A single, forwardly projecting extension 7 is either rigidly or detachably mounted to the stem, and terminates in either a pair of handgrips, 9, or a mounting therefor. The mounting between the stem and the extension may be in the form of a telescopic mounting to provide adjustment of the length of the extension. A pair of forearm supports 11 may be provided for use with the handgrips. Also disclosed is an extension piece carrying handgrips that can be mounted to an existing handlebar stem or handlebars. <IMAGE>

Description

Handlebar stem for pedal cycles The invention is concerned with handlebars for pedal cycles.

Racing cyclists tend to adopt an aerodynamic tuck by the use of handlebars with an increased forwards extension usually in conjunction with forearm supports and characterised by the arms being tucked within the width of the torso. Current commercially made schemes - known in the vernacular as triathlon handlebars or tri-bars - use either specially formed and extended handlebars which are conventionally mounted to give a permanent installation or use "U" shaped bars which are clamped to conventional handlebars to provide a detachable and/or adjustable fitting. The former are restricted to single purpose machines. The latter. if fitted and removed fresuently, can be prone to damage as well as occupying an otherwise useful part of the conventional handlebars.

The invent Ion is a handlebar stem for pedal cycles secured to the steerer tube of the front fork to carry conventional handlebars in a conventional position and with an additional, single forwards extension either rigidly or detachably mounted and terminating in either handgrips or a formed crosspiece for handgrips and used in conjunction with forearm supports.

Figure 1 shows plan and side elevation of the invention with part views of the pedal cycle.

Figure 2 shows the handlebar stem in isolation, in greater detail and in its basic form.

Figure 3 shows the handlebar stem in isolation, in greater detail and in its extended form.

Figure 4 shows side elevation of an alternative embodiment with part view of the padal cycle.

Figure 5 shows detail of a method of fitting forearm supports to the extended version of the handlebar stem.

Figure 6 shows an alternative fitting for forearm supports to the handlebar stem.

In the preferred embodiment shown by figures 1, 2 and 3 the stem 1 is of fabricated tubular construction in an inverted "L" form. One limb 2 fits into the steerer tube 3 of the cycle front fork and is clamped by a sliding wedge 12 pulled up by a screw 13. The other limb 4 forms an outwards sloping forwards extension. t clamp 5 for conventional handlebars 6 is attached to the underside of the forards extension 4 thereby compensating for the upwards slope of the extension and offering a conventional position for said handlebrs illustratec by the dotted outline 18 of a conventional stem.

The exposed end of the extension 4 may optionally be plugged 14 for protection when used as described and as shown in figure 2 or alternatively may have a telescopically fitted second extension 7 as shon in figure 3. The second extension 7 is secured to the first extension 4 by slotting the outer member and closing it onto the inner member by means of a clamp 15. Tne telescopic fitting of the extension 7 to the extension 4 will permit simple fitment or detachment with a preset position or lternauively of adjustment of length as required.

The second extension 7 will, at its extreme end, include a second - clamp 8 offset vertically from its centreline. This second clamp will carry a short, formed tube 9 to act as handgrips for the aerodynamic riding position and equating to the position achieved by current schemes shown dotted 19. The offset of the clamp 8 from the centreline of the extensions 4 and 7 together with the upwards slope of the extensions will permit two optional height settings for the handgrips 9 Figure 5 shows one form of forearm rests comprising a crosspiece 10 carrying rests or pads 11 and secured to the handlebar stem 1 by a clamp 16 and screw 17.

The lower limb 2 of the handlebar stem 1 may be secured into the steerer tube 3 by alternetive means (not illustrted) including but without limitation, expansion of the slotted tube 2 by a frusto-conical wends pulled up by a screw or by slotting and clamping the steerer tube 3 onto the handlebar stem.

The first 4 and second 7 extensions may be joined by alternative means (not illustrated) including, but without

limitation, a ee and screw similar to items 12 and 13 or by the use of 1 frustoconical wedge to expand a slotted inner member.

In an alternative embodiment illustrated by figure 4 the handlebar stem 1 will comprise a fabricated tubular construction in & "T" form.

The handlebar stem 1 is secured to the outside of an extended steerer tube 3 of the front fork by means of a clamp 20 Either of the embodiments described may Alternatively be formed and machined to a geometry similar to the fabricated tubular construction In an alternative construction, the first 4 and second 7 extensions may comprise a single permanent extension with no adjustment and for use on single purpose machines.

In another alternative construction, the second extension 7 and second handlebars 9 may comprise a permanent feature in an essentially "T" form and dispensing with the clamp 8.

In an alternative design, the handlebar clamp 5 may be mounted above the first extension 4 for use on machines where the original handlebar stem would have had an upwards slope on the extension 18 (not illustrated) In alternative embodiments, where the first 4 and second 7 extensions are secured by slotting and clamping the outer member onto the inner member, then the clamp 15 may be a separate component rather than integral with the outer member and may optionally and As shown in figure 6 incorporate the crosspiece 1-) for the forearm supports 11.

This construction would enable fitment or removal of the second

extension 7 and forearm supports 11 with one or more screws 17.

Claims

Claims

1A handlebar stem for pedal cycles as described and characterised by a detachable fitting to an existing front fork steerer tube and carrying two sets of handlebars.
2 A handlebar stem for pedal cycles as claim 1 and also characterised by a tubular extension with underslung first handlebars and a single, coaxial extension to the second handlebars.
3 A handlebar stem for pedal cycles as claim 2 and also characterised by a telescopic joint between the first and second extensions.
4 A handlebar stem for pedal cycles as described and characterised by a detachable fitting to an existing front fork steerer tube and carrying first handlebars and incorporating a fitting for an additional extension.
5 Supplementary handlebars for pedal cycles characterised by a single forwards extension carrying handlebars and with a detachable fitting to either a special or existing handlebar stem.