brake systems maintenance in bike

brake systems maintenance in bike

There are many brake types on modern bikes including caliper, V-brake, coaster and disk brakes. All have unique maintenance needs. For the purposes of this guide, we’ll touch on only a few key points. Remember, your local bike
shop is your resource when it comes to repairing today’s complex braking systems.

Fine tuning between major services

On mechanical (cable actuated) brake systems interim brake adjustments can be made using your brake system’s barrel adjusters. This is the device located commonly on your brake lever (on the brake caliper on road bikes). The adjuster allows to you add tension to your cables (like tightening a guitar string) in order to take up slack that has developed as your brake pads wear. To use barrel adjusters, turn them counter clockwise by hand and check
the setting by squeezing the levers. When the brakes feel right, lock the barrel adjusters in position by turning
the lock ring (the second knurled piece) clockwise until it’s tight against the lever. Over tightening the adjuster will
result in brake pad rub. Simply  back off a bit if this occurs. It’s important to check your brake pad condition each time an adjustment is needed. You may find your pads are worn right down and need replacement. Barrel adjusters should never be run out near their full length.

Brake pads

If pads are due for replacement you’ll need to bring them into your local shop to ensure you’re getting the correct replacement pad. All brake systems vary in the type of pad used so we will not go into detail as to how to change pads as the process differs with each system. It is recommended you have a local shop replace worn pads and re-tune
your brake system when required. In doing so the shop will re-set your barrel adjusters back in, set the pads to contact evenly to the rim or disk, ensure there is no rubbing and that your brake levers engage well before they reach the handlebar. For those interested in learning how to change your bikes specific pads, inquire with your shop’s
mechanic.

Hydraulic disk brakes

Hydraulic disk brake systems require rebleeding just like car brakes from time to time. Consult your local bike shop or owners manual for service intervals. Have a shop perform fluid replacement to ensure it’s done correctly. Brake fluid is often corrosive to painted surfaces and is harmful to health if exposed. Fluids should always be disposed of properly at facilities that accept such materials. Check with your local bike shop to ensure proper disposal.

Brake cables and housing

Frayed or damaged cables can be replaced on mechanically actuated brake systems by unbolting the cable anchor located on the brake arm, cutting off the old cable end cap (if present) and sliding the cable out of the housing system. The brake cable has a circular end that allows it to sit within a fitting within the brake lever to anchor it
the lever. You will need to turn your barrel adjuster and locking nut to so that the slot within each aligns allowing the cable to route out through the adjuster and then out of the lever fitting. Place the new cable anchor into the lever fitting so it is secure then route the cable back through the barrel adjusters remembering to re-tighten
the adjuster (leave about one full turn or so from fully tight for fine tuning adjustments).
Run the cable through the lubricated or new housing system the re-attached the cable end to the brake arm anchor. When doing so, leave approximately 2mm of space between the pads and your rim (approx. 1mm or less between disk brake pads and the rotor). Cut off the excess cable (leave about 2” max) and clamp a cable end cap to the cable using your cutters. Test the brake, it should engage evenly well before the brake lever reaches the bar. Pads should
not rub at all when the brake is disengaged.

Make adjustments to the cable tension as required until a uniform feel is achieved.

Properly aligned brakes

One of the most common brake problems is a dragging brake pad; one that remains against the rim or stays close to it after you’ve released the brake lever. The most common cause of rubbing breaks is a misaligned wheel. This can occur when you reinstall your wheel after removing it to put your bike on a roof rack or to fix a flat tire, and you don’t get it exactly centered in the frame. This causes the brake to work improperly because it’s tight on the frame and has been adjusted to align properly only on a perfectly centered wheel. Now that the wheel is crooked in the frame,
the brake can’t work correctly. To correct the dragging brake pad, simply center the wheel in the fork or frame. For most wheels, all that’s usually required is loosening, making sure they’re fully inserted in the
fork or frame, and tightening them. (If the bike is standing, just press down on the handlebars for the front wheel and the seat for the rear wheel to push them fully into the frame and center them.)
If your wheels are centered and the brake still drags, the brake may have gotten bumped and knocked out of position on the frame. Start by double-checking that the wheel is centered in the frame — you don’t want to ruin the brake adjustment if it’s actually set correctly. To center side pull brakes (road bikes), loosen the attaching bolt behind the fork crown or brake bridge until the brake is loose. (It should move sideways when you push it). Now, squeeze
the lever to hold the brake pads against the rim while you tighten the brake bolt on the back of the frame. If the brake needs minor fine-tuning after this, look for a small screw (it might be an Allen type) on top of the
brake. Clockwise turns will move the brake shoe on the side of the screw away from the rim and vice versa. (This screw is not intended for major adjustments.)
To center linear-pull brakes like caliper or V-brakes, look for a small screw in the side of the brake arm. Turning the screw clockwise will move the arm with the screw away from the rim and vice versa. This adjustment affects both brake arms and allows you to center the brake evenly so both pads contact the rim at the same time.
Mechanical disk brake systems commonly have pad position adjuster located on the sides of the caliper that allow you to dial in the contact point for the pads ensuring they touch the rotor at the same time. The entire caliper can also be loosened from its two fixing bolts and centered manually.
Again, only make adjustments you are comfortable with! Do not adjust brakes if you are at all unsure of the process!
Your safety depends on properly adjusted brakes — if you’re unsure, take it to your local bike shop for professional serving.

Brakes that stick or bind

If your brakes are binding or sticking at all, it may be that they simply need some lubrication on the cables and within the housing system or your pads may need replaced (if they are grooved and sticking against the rim). Cable systems can be lubricated by opening the brake system (freeing the cable from the brake arms or brake lever). If the housing stops are split, open the quick release on side pull brakes or unhook the 90 degree cable guide pipe on linear-pull brakes (v-brakes). This should provide enough slack so that you can pull gently on the housing sections
and free them from the frame stops. If you need more slack, squeeze the brake shut with your hand. You can lightly lube into cable housing ends and wipe lubrication onto cable sections that flow through housings to improve braking performance.
Be very careful not to get lubrication onto your brake pads or rims/rotors. Lubrication can ruin pads and seriously
impact braking performance. If you get lube onto your brake components clean it immediately with rubbing alcohol. Exposed disk brakes pads may need to be replaced as they are porous and soak up lubricants easily
which ruin the  pads. Reconnect the cables and test the brake to see if all binding/ sticking is gone.

Cleaning brake surfaces

For optimum braking, the rims and brake pads must be clean. As you use your brakes, however, the pads strike the
rims picking up anything on them and  sometimes transferring rubber deposits to the rims. The pads even pick up bits of sand and gravel that then grind the sides of the rims as you brake wearing them prematurely. This is another reason it’s important to keep the pads and rims clean (rim replacement is expensive). To clean them, dampen a corner of a rag with rubbing alcohol and scrub the rims to remove any rubber deposits or grimy build
up. Then wipe the surfaces of the brake pads to clean them. Disk brake system requires very little pad or rotor cleaning but both can also be cleaned using rubbing alcohol on a clean rag. Remember that cleaned brakes will require a break in period again so power will be reduced on your first rides after a cleaning.