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 Improved Braking Systems
One area of concern involving motorcycle braking in wet weather conditions has been the collection of water on brake discs, pads and linings. This phenomenon may adversely affect braking performance and, consequently, increase stopping distances. In 1986, members of the Transportation Research Board's Committee on Motorcycles and Mopeds reviewed a number of alternative brake designs which utilised special friction materials. The Committee concluded that "these materials may improve wet weather brake performance, under some conditions, without compromising performance in dry weather" (Nairn, 1993; p.24). The impact of wet weather on braking performance also highlight the importance of encouraging and promoting well-maintained motorcycles.
Further research has centred upon anti-lock braking systems suitable for motorcycles. Antilock braking systems monitor the wheel speed of the motorcycle and decrease brake pressure on detection of impending wheel lock (Teoh, 2010). Analysis of crash data in the United States has shown that the rate of fatal crashes was lower for ABS motorcycles compared with motorcycles not equipped with ABS (4.1 per 100,000 versus 6.4 per 100,000 registered vehicles) (Teoh, 2010). The author notes that this equates to a 37% reduction in the rate of fatal crashes per 10,000 registered vehicle years. However, riders without ABS were slightly more likely to have been cited for speeding and impaired by alcohol at the time of the crash yet more likely to have been helmeted compared with riders with ABS. The study has important limitations to recognise in ABS being an optional extra for riders and as such may be a cohort different from riders who choose to purchase motorcycles without ABS.
Hurt (1981) demonstrated that many motorcyclists involved in crashes failed to use full braking capacity because they feared such a strategy might lock the brakes and capsize the motorcycle. Moreover, imbalances between the effects of the front and rear brakes can contribute to crash involvement. To encourage effective brake application and remedy these problems anti-lock brakes are being developed. The chief obstacle to their widespread use appears to be cost. Although some European and Japanese manufacturers offer anti-lock braking systems on selected models there is extra cost (Nairn, 1993).
Systems that equalise braking between the front and rear brakes may be more cost-effective than the more sophisticated concept of anti-lock braking. They have also been shown to reduce the stopping distance among experience riders on closed-circuit tracks (Green cite in NHTSA, 2010).
Information sourced from A review of potential countermeasures for motorcycle and scooter safety across APEC (Full report and References [PDF, 304KB]). |
