02 Jan 2013
January 2, 2013

Rear Brakes

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Rear Brakes

Let us explain why rear brakes are important and what to do about taking care of them and servicing them.

Most modern motor vehicles have two sets of brakes, front brakes and rear brakes. Even two wheeled vehicles such as Mountain Bikes and Motorcycles have rear brakes and these have a very specific purpose which we explain as follows.


The first thing rear brakes will provide a back up in case of a failure of the front brakes. Not only that in modern brake systems it is quite normal for the rear brakes of an vehicle, whether two wheels or four to rely on the rear brakes for 20-30% of the vehicle stopping effort.


Whilst we don’t recommend rear foot braking to our motorcycling friends which far too often can cause rear wheel lockup, fast rear tire wear and does not at all maximise the stopping power of a motorcycle, it is a common habit especially on larger big twins in the USA. Things like girder front forks tend to dissuade the rider from grabbing a handful of the front brake lever and when you consider that 70% of the braking comes from the front riding a Motorcycle relying only on the rear brakes just does not make sense.


Because they are at the back of any vehicle rear brakes tend to get dirtier, get more water spray and suffer corrosion. Add that to the myth that a rear brake is mostly for a handbrake and it is hardly surprising some of the fastest selling brake parts in the world are for rear brakes where caliper corrosion and seizure are quite common.


Every 20,000 miles at the outside, any good driver will have the rear caliper checked for seizure. Plus this does not apply just to older cars, a brand new model deluxe car after 20,000 miles or so can suffer enough corrosion on the rear brakes to warrant stripping and overhaul of the rear brake caliper. This is very often overlooked and results in poor and imbalanced braking and fast rear brake pad wear.


On Motorcycles, being an unstable vehicle the effective function of the rear brake is critical; a balanced application of first front gently followed by rear brake action is the professional way to stop a motorcycle. Applying the front brake first helps weight transfer to the front wheel and plants the tire firmly on the road, the application of the rear brake immediately after maximises the stopping power of the bike.


On Motor cars it is quite often that a brake bias valve or load valve chooses the amount of pressure that is distributed to the rear brake. This explains why some truck rear brakes wear out before the front because the rear end, carrying the loads of a busy operator truck set themselves to do more work than the front when the vehicle is loaded.


One more thing on rear brakes is that on cable operated hand brake systems, it is critical to check and either lube or replace any stocking cables attached to the rear brake caliper. It is no good replacing a caliper, spending money on new pads and having a sticking cable send all this to the trash can for you, check those cables, check slider ways on calipers and ensure free operation of rear brakes at all times.