The most common method to adjust bike brakes uses a wedge-type barrel adjusting mechanism, which consists of a split ring that screws onto the caliper arm and the brake cable attaches to it via a screw-on cap.
The “split ring” is usually a thin piece of metal that has been cut in half, and then had its halves separated with a small gap of separation. This creates two parallel pieces of thin metal that can be rotated together or away from each other and thus tighten and loosen the cable. When they are tightened towards one another, the cable is tightened, and when they are separated the cable is loosened. There is a small screw on the outer ring that can be adjusted to determine how much you want to tighten or loosen your brake cables.
If your brakes feel scratchy or “grabby,” then you have too much tension on the cable, and will need to release some tension in the cable by loosening the split ring. If your brakes make a loud squeal when you use them, this is also usually an indication that there’s too much tension on the cable and you will need to loosen it up. Most split rings have numerical graduations that allow adjusting bike brakes. A word of caution, though; If the split ring has too much tension on it or is not adjusted properly, then it can snap. This happened, once when the ride forgot about this tensioning mechanism and rode down a hill while standing up.
The other common adjuster mechanism is a “cam” or the “noodle.” A cam is like an arm with teeth on one end. This arm meshes together with another similar but stationary arm, and every time the moving arm squeezes your brake cable it forces the stationary arms to rotate. How much they rotate depends on how far you pull your brakes. If you pull your brakes too far, then the noodle will rotate too much and you’ll be in for a very awkward ride because your brakes will barely work.
When you pull your brake levers, there is usually an arm or wire going from your lever to another part of the bike called a “noodle,” which is essentially a stationary cam that rotates when you pull the brake cable. There is usually a small screw in this area, which can be adjusted to tighten or loosen your brakes. If it’s too loose, then your brakes will hardly work at all, but if it’s too tight then you are taking a risk of snapping your noodle.
How do you find the right tightness for your brakes? The best method for this is to start out with no tension on the cable whatsoever. Pull the lever slowly until you feel it engage the brake pads, and then slowly let up on that pressure until you can hear or feel that they are starting to disengage again. Then slightly increase that pressure until you feel they are just barely touching the rim. This way, you have enough tension on your brake cable that it is working, but not so much that your brakes only have a fraction of an inch before being entirely disengaged.
If you find yourself adjusting bike brakes often, either because they are coming loose during riding or simply due to fidgeting while you ride, then there are a few ways to prevent this. You can use “nipple washers,” which are small pieces of rubber about 1/8″ in diameter that fit on the outside of your brake arms and provide friction against the split ring or noodle so it doesn’t move around. Split rings also have these built-in. The other option is “zinc carbonate,” which is a grease that you can apply to the outside of your brake arms, where they rub against your rim or tire, depending on their design. Just remember that these things will make adjusting your brakes more difficult; if you’re doing this often then there’s probably something wrong with your brakes or your brake arms.
If you have a rear caliper brake, be sure to adjust the spring tension exactly as indicated in your owner’s manual so that it doesn’t drag when you engage the brakes. It is also best to keep both pads equally adjusted and even with each other, otherwise this can increase braking effort or prevent proper engagement. If you have disc brakes, make sure that both pads are adjusted evenly. Another thing to be aware of is brake shudder caused by warped rotors. Do not ride your bicycle if this happens; it can lead to complete caliper detachment.
It’s quite easy to adjust the tension on your V-brakes, but not so simple on cantilever brakes. If it’s just one break that is having problems, then you can usually adjust bike brakes fine enough by adjusting the straddle wire, a small, thin cable that runs between the two sides of your cantilever brake. But if both are having issues or you want to totally overhaul your bike’s brakes, then replacing the brake arms is a good option.
If you have disc brakes, then adjusting the tension on your brake pads will depend mostly on the design of your caliper, if it’s one that has two bolts or one bolt with a pad positioner spring. In either case, there may be an adjustment screw inside each arm to adjust how far the pad presses against your rotor. It’s also important to make sure that your pads are all even; adjust them both side to side and front to back until you get an even amount of braking power on each.
If your brake levers appear bent or misaligned, then this may actually be a result of faulty brake lever blades or cable tension. If this is the case, then you’ll need to replace your brake levers entirely but don’t worry, it’s an easy fix.
Finally, if all else fails and you are still experiencing problems with your brakes, consider replacing them completely. This is ideal for newbies who simply want a simple system that works well without needing to be constantly fine-tuned.
Generally, the rule is that the closer you are to your axle, the easier it is to adjust, and remember that quick release adjustments are intended for emergency brake tightening only. Do not use them as your daily adjustment method; this will create slack in your cables and make them more likely to come loose during riding.
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