GB2467544A

GB2467544A - Handlebar stem angle adjustment

Info

Publication number: GB2467544A
Application number: GB0901814A
Authority: GB
Inventors: Paul John Buckworth
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-02-04
Filing date: 2009-02-04
Publication date: 2010-08-11
Also published as: GB0901814D0

Abstract

A handlebar height adjustment assembly enables the angular position of a handlebar stem 1 to be altered relative to the steerer tube 3 by the selection of an appropriately angled insert 2 or spacers between the stem 1 and the steerer tube 3 to set such angular position to the desired position for the individual rider.

Description

HANDLEBAR STEM HEIGHT ADJUSTMENT DEVICE

Description

This invention relates to a device for height adjustment for a handlebar stem attached to the steerer tube of a bicycle.

Conventional stems do not generally provide for a variation of height adjustment of the handlebars other than being fixed in position on the steerer tube in one of two alignments (up or down). This does not allow the handlebars to be positioned at a height suitable for the individual rider unless there is surplus length on the steerer tube (which is generally not the case for most bicycles) for the stem clamp position to be varied.

Incorrect height positioning can lead to rider discomfort andlor injury.

Those adjustable stems that are available on the market typically have an articulated joint in the stem tube providing for angular adjustment and this joint can compromise the rigidity of the stem, add unnecessary weight and also increases the manufacturing complexity of the product.

Where inserts have been proposed as a design alternative to give height adjustment, such inserts have been limited in application to simply varying the position of the stem within the existing range of possible location available on the steerer tube itself.

As such they rely on there being surplus length already existing on the steerer tube thereby allowing a range of possible positions of the stem on the steerer tube. Most bicycles do not have such surplus length available.

To overcome these problems, the present invention proposes an insert or spacers between the handlebar stem and steerer tube which may incorporate an angular offset enabling the stem to be angled upwards (or downwards if inserted the opposite way round)relative to the steerer tube thereby altering the height of the handlebars accordingly. The dimensions of the clamping mechanism of the handlebar stem would be matched to the outer surface of the insert (rather than to the outside diameter of the steerer tube as in conventional designs). The inside diameter of the insert would be matched to the outside diameter of the steerer tube (which are generally of standard size).

Inserts or spacers of different or zero angular offset would be available allowing a single stem to be set at a range of different possible angular alignments according to which insert or spacers were selected by the rider.

The invention will now be described solely by way of example and with reference to the accompanying drawings.

Figure 1 shows a cross section view of the assembly with the insert or spacers between the steerer tube and handlebar stem.

Figure 2 shows a plan view of a possible insert design.

In figure 1, a handlebar stem 1 comprising a conventional handlebar clamp 5 and steerer tube clamp 6 fits to the steerer tube 3 over an insert or spacer 2. The insert or spacers 2 are shown with an angular offset, denoted 4. A range of angles are possible and the required angle of such offset would be selected by the individual rider to provide the angle and therefore handlebar height to suit their own preferences.

Figure 2 shows a plan view of a possible insert design. In this example the insert 2 is cylindrical in shape with an internal bore at an angular offset 4 in one plane relative to the axis of the cylinder. This particular example also includes a slot or groove 7 in the insert which would enhance the grip of the stem clamping mechanism 6 and the insert 2 against the steerer tube 3.

Claims

Claims 1. A handlebar height adjustment assembly which enables the angular position of a handlebar stem to be altered relative to the steerer tube by the selection of an appropriately angled insert or spacers between the stem and the steerer tube to set such angular position to the desired position for the individual rider.
2. A handlebar height adjustment assembly according to claim 1 comprising a handlebar stem with the steerer clamp sized to allow the use of an insert or spacers between the clamp and the steerer tube.
3. A handlebar height adjustment assembly according to claim I with insert or spacers with internal diameter matched to the steerer tube of the bicycle and outer surface matched to the dimensions of the clamp mechanism of the stem and in which the internal diameter and external shape may be offset angularly.
4. A handlebar height adjustment assembly according to claim 1 in which the insert or spacers can be reversed in order to provide equal adjustment in the opposite direction for a given insert or spacers.