New Website Notice for Edinburgh Bicycle

Please note that the Edinburgh Bicycle Co-Operative now has a new website. To visit the new website, please follow this link.

If you have bookmarked a page from the old website, please update your bookmarked page so that you can go straight to our new website. Thank you.

The Edinburgh Bicycle website team.

The first many people heard of 'V' shaped brakes was when Shimano introduced a V-brake system with their '96 model bikes. However, Keith Bontrager, mountain bike design guru, had experimented with this concept several years before but did not launch it on the market because of incompatibility with all the brake levers available at the time. Ben Capron, founder of Marinovative, did launch a long cantilever arm brake in '89, and in '92 modified it to a side-pull design. The current manifestation of Capron's design is the Cheap Trick - a long arm, side-pull.
Shimano have tested their version since '93 and their brakes are the only ones with the parallel-push mechanism. They are also the easiest brakes when it comes to replacing pads.

WHAT ARE V-BRAKES ?

The V-brake system is a long cantilever arm, side-pull (or linear pull) braking system. The most obvious difference between these brakes and regular cantilevers is that the arms are much longer. These arms function as levers and their length provides a brake with a much higher leverage ratio. (This can be understood if you consider a sum of the moments around the brake boss, with one force at the top of the brake arm and the other at the brake pad.) This means less force is required at the brake lever.

A Cable Guide Tube ("turn pipe") B Accordion Cable Protector C Easy Fitting Cable Fixing Bolt D Cartridge Type Pad E Parallel Push Mechanism F Arm Fits Standard Cantilever Bosses

Confused? To clarify this concept, go to your local tax office and stand in front of one of their doors that has a spring closer. Now push on the door (from the push side of course or you'll be even more confused) with your hand very close to the hinged side. Next, push on the handle, which is far away from the hinged side. It's obviously much easier to open the door when you push on the far side. This is how the V-brake works, less force to do the same task. Oh, and if the people at the tax office come out and tell you to go away, say you pay taxes and it's your door, so you can use it as much as you want.

Standard Cantilever showing Straddle Cable

The next difference is the elimination of the straddle cable. Getting rid of the straddle cable eliminates the hassle of fiddling with cable heights and lengths to maximise power. It means no more trigonometric analyses to find the particular sweet spot for your system. Also the pad holders can only be mounted in one of two positions in the horizontal direction. This eliminates messing about with the extension of the brake pad from the canti arm.

The third difference applies to the XT/XTR versions. They have a parallel push mechanism. This is a parallelogram arrangement that pivots the brake pad so that it is parallel to the rim at all times. This eliminates uneven pad wear and the chances of brakes diving under rims. As a result pads do not have to be repositioned as they wear.

The pads themselves are different too. They are held in place by a single retainer pin and they are very easy to replace. Remove the pin, then the pad, put in the new pad, then the pin. Done. No readjustments of the brake, except cable length, are needed.

SUMMARY:

lower brake lever force needed, very easy setup, less maintenance, easier pad changes.

QUESTIONS AND ANSWERS
ON V - BRAKES

Do I need special pads ?

Yes, V-brakes use specific pads. The pad retention system necessitates this, as does the design of the brake. V-brake pads are much thinner and thus a harder compound is used. Several manufacturers are producing V-brake pads.

Do I need new brake levers ?

Yes, you will need new levers. The brakes exert a lot of force on the rim for a small input force (remember the moments, see above) and this is the reason regular levers will not work. The leverage ratio of standard levers is too low. In other words, a standard lever moves less cable but with a higher force. The force exerted would be too much for V-brakes, leading to very poor modulation (highly on/off). In addition, the lever would be right against the handlebar by the time it engaged the brake. A V-brake lever pulls more cable and exerts less force on the V-brake, giving nice modulation and a normal amount of lever travel. See levers below.

Shimano Lever M600. The cable is mounted in the lever handle giving a lot more travel than conventional levers.


Shimano Lever ST-M950
This is a V-Brake lever with a servo facility, allowing the braking action to be customized.

Will V - Brakes Fit my bike ?

Yes, if you have existing braze-on fittings to accommodate standard cantilever brakes. Otherwise no, unless you're handy with welding gear. If you are in any doubt please contact us.

Is the cable routing the same ?

No, your new cables are fitted straight from the lever to the brake. This means that you can use outer housing for the full length of the cable travel if you fancy. Existing braze-ons, i.e. a hanger or stop on the handlebar extension and a wee braze-on that looks like a bit of macaroni at the seat post, are made redundant. There are plenty of options but it is worth discussing your bike with a mechanic to come to the best solution.

Are my brake levers on the wrong side of the handle bars ?

Ha! As most of the world drives on the wrong side of the road, many manufacturers make brakes for these irresponsible nations. Consequently their bikes have the front brake lever on the left of the handlebars. Tut tut. If you have a problem setting up your levers correctly (front brake, right-hand lever; rear brake, left-hand lever) the solution is a 135-degree turn pipe - supplied with some models and available as a spare for others.