GB2502599A - Aerodynamic handlebar - Google Patents

Abstract

A cycle including a sprint (or drop) handle bar in which the handle bar comprises a substantially horizontal portion, held in place on the front headstock of the bicycle and generally transverse to the frame of the cycle, two portions extending downwards from each end of the horizontal portion and two handle portions extending rearwards from the bottom of the downwards portions, each handle portion generally parallel to the frame of the cycle, and in which the horizontal portion and the vertical portions of the handle bars are of aerofoil cross section (A-A) and that the horizontal section 25B directs air passing over it upwards by up to 10°.

Description

Handle-Bars for Cycles [0001] This invention relates to sprint handle-bars for cycles. Such handle bars, which are often also known as drop-handle bars are used widely in cycling both for racing purposes and leisure riding.

[0002] In each application of sprint handles bars in a cycle, it is desirable that the drag induced by the combination of handle bar and wake flow over a rider be minimised.

[0003] According to the present invention a cycle includes a sprint (or drop) handle bar, said handle bar comprising a substantially horizontal portion, held in place on the front headstock of the bicycle and generally transverse to the frame of the cycle, two portions extending downwards from each end of the horizontal portion and two handle portions extending rearwards from the bottom of the downwards portions, each handle portion generally parallel to the frame of the cycle, characterised in that the horizontal portion and the vertical portions are of aerofoil cross section and that the horizontal section directs air passing over it upwards by up to 100.

[0004] In another embodiment the transition between the horizontal portion and the downward position is aligned with the longitudinal axis of the forearms of a rider, and is the downward portions are align with the arms to the handles which are inside vertical planes drawn through the transition between the horizontal and downwards sections.

[0005] In such an embodiment the aerofoil section of downward sections of handle-bars directs air towards the torso of a rider, an in board deflection of up to 100 is desirable to achieve this.

[0006] In such an embodiment preferably a vertical plane through the middle of the handle portions is about 25mm inside a vertical plane through the corresponding downward portion of the handle bars.

[0007] Normally sprint handle bars are normally hollow. It has been found that by placing a aperture in the front of the handle bar to allow air to enter the hollow interior of the handle bar, and having a vent in the handle portions behind the hand position. Preferably the vents open at the tops of the handle portions behind the hands.

[0008] In order that the invention may be more fully understood, embodiments will now be described with reference to the accompanying drawings in which: [0009] Figure 1 shows a conventional sprint handle bar; [0010] Figure 2 shows a modified handle bar according to a preferred embodiment of the invention; [0011] Figure 3 shows detail of a section on the line A-A' of the figure; [0012] Figure 4 shows detail on the line B-B' of the figure and [0013] Figure 5 shows a sprint handle bar with vents.

[0014] In figure 1 a rider 10 is mounted on a sprint bicycle 12 including a sprint handle bar 14. The handle bar 14 comprises a substantially horizontal portion 16, held in place on the front headstock 18 of the bicycle 12 and is generally transverse to the frame of the bicycle. Two portions 20 extending downwards from each end of the horizontal portion 16 and two handle portions 22 extend rearwards from the bottom of the downwards portions 20, each handle portion 22 generally parallel to the frame of the cycle.

[0015] In figure 2, which shows a modified handle bar 15 incorporating features of the invention. The handle bar 15 again includes a horizontal portion 16 and downward portions 20, but in this case the transition points 24 between the horizontal portion 16 and the downward portions 20 are aligned to be in front of the longitudinal axis of the forearms of the cyclist 10. The downwards portions 22 are now aligned in front of the arms of the riders to the handle portions such that the handle portions are now about 25mm inside a vertical plane drawn though the transition point 24.lt will be seen that the horizontal portion of the handle bar of this embodiment is about 50mm longer to its transition point 24 compared with the length a conventional sprint handle bar (shown in cross hatching) to its transition point 24A [0016] Figure 3 shows a preferred cross section of the horizontal portion of a handle bar according to this invention. The section on line A-A' is an aerofoil cross section having a chord to thickness ratio of 3:1 and a thickness of 80mm. The preferred nose down variation 25B was compared with a section 25C with its nose up, and a section 25A with nose and chord aligned. The total drag on the bicycle and cyclist in the aligned arrangement (profile 25A) was 49.26 Newtons, in the nose up configuration (profile 25B) this had increased to 49.44 Newtons but in the nose down configuration 25B it decreased to 48.86 Newtons. A decrease resulted from this arrangement alone of about 1%. Obviously these readings are from one particular cyclist and will vary from cyclist to cyclist, but the principle is clear.

[0017] Figure 4 shows a preferred cross section of the downwards portions of a handle bar according to this invention. The section on line B-B' is again an aerofoil cross section having a chord to thickness ratio of 3:1 and a thickness of 80mm. The preferred nose out (directing air towards the torso of a rider) profile 26B was compared with section 26A with nose and chord aligned. Again useful improvements are achieved.

[0018] Allthese improvements in figures 2 to 4 to the profile of the sprint handle bars were tested together, and a total saving of 2.O9Newtons (over 4%) was achieved in comparison with the best current sprint handlebars, and 4.24 Newtons against the base line handle bars and cyclist used for the experiments figures 3 and 4 (a saving of over 8%).

[0019] Figure 5 shows a further modified handle bar 17 incorporating. The handle bar 17 again includes a horizontal potion 16, fitted to the headstock 18 of a bicycle 12 and downward portions 20. In common with conventional sprint handle bars, the handle bar 17 is hollow, but it has apertures 30 facing the direction of travel of the bicycle in the downwards portions 20. The actual position of these apertures whether on the downward portions or the horizontal portions appears not to be critical provided they face the direction of travel. Vents 32 are provided in the handle portions 22, positioned such that the vents are behind the hands of a cyclist 10 in the cyclists' normal cycling position on the bicycle 12. It was found that in a central position venting upwards behind the riders hands the venting arrangement reduced drag by 1.39 Newtons compared with the known handle bars, and significantly outward directed and inwardly directed vents increased drag.

[0020] The modifications to sprint handle bars described in this invention can be used separately, but for best aerodynamic advantage they should obviously be used together.

Claims (9)

1. Claims 1. A cycle including a sprint (or drop) handle bar, said handle bar comprising a substantially horizontal portion, held in place on the front headstock of the bicycle and generally transverse to the frame of the cycle, two portions extending downwards from each end of the horizontal portion and two handle portions extending rearwards from the bottom of the downwards portions, each handle portion generally parallel to the frame of the cycle, is characterised in that the horizontal portion and the vertical portions of the handle bars are of aerofoil cross section and that the horizontal section directs air passing over it upwards by up to 100.
2. 2. A cycle according to claim 1 characterised in that the transition between the horizontal portion and the downward position of the handle bar is aligned with the longitudinal axis of the forearms of a rider, and is the downward portions are align with the arms to the handles which are inside vertical planes drawn through the transition between the horizontal and downwards sections.
3. 3. A cycle according to claim 2 characterised in that the aerofoil section of downward sections of the handle-bar directs provides an inward deflection of up to 100 to air passing the downwards sections.
4. 4. A cycle according to any preceding claim having handle bars characterised in that a vertical plane through the middle of the handle portions is about 25mm inside the transition between the horizontal portion and the vertical portions..
5. 5. A cycle according to any preceding claim characterised in that the handle bar is hollow and has an air inlet substantially facing the normal direction of travel and an air outlet behind the hand position of a rider.
6. 6. A cycle according to claim 5 characterised in that the air vent is on the top of the handle portion of the handle bar.
7. 7. A cycle having a handle bar with an air inlet substantial facing the normal direction of travel and an air outlet behind the normal position of a cyclist's hands when riding.
8. 8. A cycle having a handle bar according to claim 8 said handle bar being a sprint handle bar and in which the air outlet is on top of the handle portion.
9. 9. A cycle having a handle bar substantial as hereinbefore described with reference to the accompanying drawings.