Bike Friday User Group UK

Technical Support - Brakes

Important Notice

Information is given here in good faith, but no one should carry out any work on any bicycle unless they are competent to judge for themselves that the action proposed is safe, nor should they attempt such work unless they have sufficient experience and the necessary equipment to complete the work safely. The compilers of this information, the UK User Group, the UK distributors, and Green Gear cannot be held responsible for the actions of those who read these pages, or any results of those actions.

Brakes are obviously one of the most important parts of a bicycle, since their correct operation is essential to the safety of the rider and others. Brakes must be correctly maintained, and if you are in any doubt about their condition, or how to look after them, you should contact a competent bicycle shop to carry out any necessary work.

This page is still in preparation. The subject of brake adjustment is extensively covered in cycle maintenance books and cycling magazines, and we suggest that you look there for relevant information.

The performance of the brakes on any bike fitted with rim brakes is considerably influenced by the condition of the rims. Make sure that the rims are clean and not subject to any damage (dents etc) and that the wheel is running true. Keep the braking surface of the rims clean, and make sure that you do not use any lubricating substance when cleaning these surfaces, and that no oil or other lubricant gets on these surfaces. Gunge collecting on the rims after rain seems to act as a lubricant and seriously reduce braking effect, even after it has dried, so clean the rims after using the bike in the rain.

The type of brake block used can also considerably affect braking performance. Some blocks fitted originally to bikes are not particularly effective. In the UK, Aztec blocks have generally got a good reputation, although this is not to say that there are not other makes which are just as effective, or even more so.

Rim brakes work by pressing the brake block against the rim. Blocks are generally at least slightly abraasive - some makes more so than others - which means that applying the brakes results in wear of the rim. It is therefore important to monitor the state of the rims, as failure of the sidewall could have catastrophic consequences. How frequently you do this will depend on the mileage you cover, and how hard you are on the brakes, but it seems unlikely that most riders would need to do this more than once a year, and most riders will not need to start checking for a couple of years on a new bike. Take advice from a competent bike shop if you are in any doubt regarding the condition of the rims, or when and how to check them. Rim failures ae not common, but you should be aware that they can happen if precautions are not taken!

As a result of the folding process, the cable runs of Bike Fridays are longer than on most bicycles, and the rear brake cable in particular is not only longer, but also follows a rather tortuous path. The result of longer cable runs and bends in the cable is to produce friction in the operation of the cable, which requires more braking effort for the rider, and reduced braking efficiency. It is therefore particuarly important with a Bike Friday to keep all the braking system clean and properly lubricated - obviously you should NOT lubricate the brake blocks or rims though!! Also make sure that there are no unnecessary kinks or bends in the cables.

The more sporting Bike Fridays seem to be fitted with the Shimano 105 dual pivot calliper brakes, which are well made and reasonably efficient, even with the long cable run to the back. Other current models are fitted with (cantiler) V brakes, which are also very effective. (Generally a criticism of V brakes is that they are almost too powerful, but when used on Bike Fridays, with long cable runs, the result is good.)

Photo of brake, showing noodle On those models fitted with calliper brakes, keeping the brake mechanism and the cables clean is very important. The shaped cable outer tube ("noodle") - see photo - which is used at the brake end of the cable on V-brakes can also be used to improve the cable run to the Dia Compe Big Dog dual pivot calliper brake use on some older models, and can improve performance usefully. Personally I am not at all impressed with the Dia Compe on a Bike Friday, although providing everything is clean, and the "noodle" is used, the performance is more than adequate. Aztec blocks made a very small improvement to performance on my bike, but did not entirely solve problems when the cables were worn and dirty. Unfortunately the design of the bike requires a brake with a very long reach (long brake arms), and there do not seem to be any alternatives to the Big Dog readily available (and of course there is no guarantee that any other model would be better). The Shimano 105 is not available with a long enough reach to fit these bikes, such as the New World Tourist fitted with the 406 wheels. Some owners have upgraded their older bicycles to take V brakes, but this requires the fitting of bosses for the cantilever brakes on the front and rear forks, so it is quite a major job and quite expensive, and can only be undertaken by the factory or a competent specialist frame builder with the necessary brazing skills (or replacement of the entire front and rear fork by the factory). If anyone reading this has any alternative suggestions for improving the braking performance of bikes fitted with the Big Dogs, we would be delighted to hear from them!

More on brakes - fitting V-brakes to an earlier New World Tourist

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