Brake Maintenance
There are 4 different types of brakes generally available (Cantilever, U, V and Disc) which are connected to your brake levers either mechanically(cable) or hydraulically. In terms of performance a properly bled (we'll talk about this later) hydraulic brake will give much better performance than a cable brake. This is because when applying pressure to the brake levers a hyrdaulic fluid is put under compression but due its molecular arrangement it cannot be compressed, giving 100% transfer of energy from your fingers to the brake pads. A cable system however will stretch a little and suffer from friction within any protective lining. The pros and cons of mechanical Vs. disk brakes are listed below.| Mechanical | Hydraulic | ||
| Pros | Cons | Pros | Cons |
|
Easy to adjust Fair price |
Dirt can clog the cable If this happens it can cause less smooth breaking |
Powerful braking Use fluid cable Less likely to become damaged Less affected by weather |
Difficult to adjust If not bled correctly braking can be dangerously poor More expensive Regular maintenance needed |
If you can afford them disc brakes are much more efficient and less likely to be damaged. The reason for both of these advantages is simply that with the braking surface is kept away from mud/water and most impact damage with disc brakes where as U or V brakes are right beside the tyre and the rim can become deformed due to impact damage.
Aligning You Brake Pads (for Cantilever, U and V Brakes)
For a great guide on how you brake pads should be aligned try this page on on parktool.comCantilever Brakes
1. Remove the brake pads and loosen the cable anchor bolt and tighten the cable until the bottom part of each arm is vertical then tighten the anchor bolt again.2. Replace the brake pads and align them correctly (see the "Aligning Your Brake Pads" section)
3. To set your cable tension up correctly you will first need to adjust the the cable splitter (if it is a set-up that has an adjustable option here). Usually done by loosening the pinch bolt and sliding it up/down as required. Ideally it should be set as low as possible whilst not interfering with tyres or mud guards. You can then adjust the final parts by pulling the cable through the pinch bolt on the brake arm until it ssuits you. Fine tuning can be done by adjusting the cable tension at your brake levers.
U-Brakes
U-Brakes are generally not used on mountain or road bikes these days aside from the more low-end models though they are still common on BMX bikes. Their benefit relies on their durability, both in the brake arms strength and their resistance to knocks and impacts. Compared to a V-brake they are tougher but the amount of braking pressure they can apply is limited by the brake lever used and they are a little more difficult to adjust. The most important part of maintaining any brake system is setting it up correctly.1. To start with, loosen the springs a little on the brake arms anything up to a turn should be enough and screw the grub screw adjusters in a little for fine tuning once you've finished the rest of it.
2. Adjust the brake pads to contact the rim correctly, this is done easiest by loosening off the bolts that hold the pads and squeezing the brake arms until the pads touch the rim. Move the brake pads until they are aligned correctly then tighten the bolts before releasing the brake arms. For information on how your pads should be aligned see the "Aligning Your Brakes" section near the top of this page.
3. Loosen the cable anchor bolt and squeeze the brake pads against the rims again and pull the cable tight. You may want to use pliers to keep hold of the cable, tighten the anchor bolt while still holding the cable. (Don't worry, when you let go the tension applied to the cable will pul the pads away from the rim)
4. The springs now need tension reapplying, the spring on your left as you face the bike is tightened by turning the screw clockwise, the one on the right counterclockwise. Starting on the left, screw clockwise until the pad is about 1 - 1.5 cm from the rim. While holding it in place, tighten the Allen bolt to lock in the adjustment. Tighten the spring your right by turning it counterclockwise. Turn until both brake pads are an equal distance from the rim, then tighten the Allen bolt.
5. When you have completed the above steps, give your brakes a quick test and adjust the barrel adjusters on your brake levers to your satisfaction.
You can't get hydraulic U-brakes to my knowldge so as with all cables on your bike you should take care to clear any dirt from around the cable outer and really should buy cables that have are lined with a low friction sheath made from plastic. This also helps reduce wear and corrosion of the cable, increasing its life. Most cables bought these days have some kind of lining however if you do have an unlined cable you should grease it up to protect it from water and decrease friction against the cable outers. You can also fit seals that attach to your cable-outers and seal around the cable itself to further reduce the ingress of any dirt or water in to the cable outer.V-Brakes
These are very easy to set-up and maintain. The most common problem is that the brakes can be knocked off centre or only pull from one side. This is fixed by adjusting the spring pre-load on each arm, usually by turning the small screw at the bottom and just behind the brake arms (see picture)Disc Brakes
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