LarrySellerz

I am having a ridiculous amount of trouble with the cheapest of disc brakes. The bike in question has been taken in a total of 5 times to 3 different bike shops to get the brakes adjusted. Im not picky, they just get out of alignment very quickly and hardly stop me. My attempts at fixing them have been woeful.

I’ve spent $60 getting brakes adjusted, not to mention favors called in, the bike is less than a year old and I got it for $150 from a shop.

I’m taking the bike to a shop soon, and I’m thinking about upgrading the brakes. A mechanic at a lbs told me my brake system is a PITA and will always get unaligned. Normally I’m super anal about wheel rub but at this point im so fed up that I don’t even care about that and I still can’t get it to stop. Anyone else upgrade brakes in a situation like this? It’s a single speed and the bike I’m using the most.

PeteHski

I've never had any issues with reasonable quality disc brakes, so I would go for the upgrade.

vespasianus

The bike was $150? If that is the case, I would consider just buying a new bike with better brakes. A good set of entry level mechanical brakes will be close to that price (installed).

Jeff Neese

No one can tell you whether it's worth it or not without knowing more about the bike. You said you paid $150 but that doesn't indicate how good a bike it is. If it's a $150 Walmart BSO then it's probably not worth it. If you scored a good bike for cheap off Craigslist and it's worthy of being a keeper, then of course you want the best brakes you can afford.

You may want to provide more information about what the bike is, and what brakes are currently on there.

delbiker1 

IMO, the trouble starts with "cheapest". We are talking about one of the most important aspects of riding a bike, being able to stop in a timely, safe manner. Does one really need advice for this?

BlazingPedals

If the brakes have needed that much attention, and apparently will continue to do so, why haven't you learned how to adjust them yourself yet? The other points are good, an upgrade would be a good idea, IF the bike is worth the expenditure. Note that any mechanicals that only move one side will constantly need adjusting and rotor truing, just because of the way they work. So I wouldn't aim for entry level either.

Koyote

A $150 bike has ****** brakes? I'm shocked.

sloppy12

Just throwing this out there but you sound like you ride a little on the aggressive side. if the brakes in question( as mentioned above) only move one pad just get used to it. If you upgrade make sure whatever you pick both pads move. make sure the rotors are straight I have used some of the super cheap mechanical brakes and got them to work pretty decent.

couldwheels

I've used the cheapest disc brakes without problem as soon as I figured out how to adjust them properly. But ofc, it took me a while to figure out the "safe way" to adjust these cheap calipers. It's not as simple as getting it centered, in fact, you actually need to offset it to the piston side. Most LBS don't have a clue about it.

Loosen the nut that holds the brake cable to the caliper piston arm to loosen the cable and adjust the caliper housing so the side of the housing with the piston is much closer to the rotor than the other side. As close as you can get without the housing nor the piston side brake rubbing the rotor and then tighten the screws holding the caliper housing to the frame. And then adjust the brake pads so that they close as possible ot the rotor without rub.

That is what you do with very cheap one-piston calipers. These cheap calipers don't like their piston arm swiveling close to the limit. The ball-bearing action pushing the piston can "Spill" over the recess near the limit and cause the piston to pull back and you lose braking effectiveness. Quite dangerous. This is why you need to offset the caliper. Getting it centered over the rotor is a bad idea.

Finally, get your hubs and rotors true. If your hub is not true / wobbling due to bent axle or watever, you need to replace that hub, to eliminate the rub (and it rhymes!). Assuming your hub is perfect and the rotor still have wobble, you can true it yourself with great care using disc rotor truing tool or with the biggest adjustable wrench you have.

Rolla

I think you're throwing good money after bad, but if it's the bike you ride the most, it should probably have a decent brakes.

2old

As above, it depends on whether your bike is worth the expenditure, but Shimano's MT 200, least expensive (AFAIK) hydraulic brakes ($120 or so per pair), stop my Giant FS bike extremely well.

seypat

You're a big dude who rides aggressively. Keeping things aligned and working on any bike you ride will require more effort.

veganbikes

Brakes only slow you down. How are you gonna catch all the ladies and ride next to them if you are slowing down.

To those reading this and not knowing the history of the OP. Cheap parts are not designed to last or work well they will need constant tuning to make them barely work and in general they are not worth the time or money and if the bike comes with a lot that stuff or is very cheap like described above it is probably not worth upgrading parts on it and just worth saving your money towards something that will work well. Cheap stuff is for rich people who can afford to waste money and time.

Koyote

Short version: don't throw good money after bad.

LarrySellerz

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hmm it sounds like the shops I’ve been taking it to don’t know how to properly adjust it. You’re right that I should learn, but in the meantime I might have to bring it back to the shop I got it at and see if I can pay him but I don’t like wasting his time. I just feel bad because the shop only really sells racing bikes and he just happened to have that beater that a shop employee built out of a parts bin. Can’t expect the same level of service as if I bought a new bike there ya know.

BlazingPedals

Adjusting cheap mechanical disc brakes:
1. undo the brake cable.
2. position the caliper so that the inside (non-moving) pad is as close as you can get to the rotor without rubbing.
3. Using the pad adjuster, adjust the outside pad so that it is also close without touching.
4. Now, attach the brake cable and adjust its tension so that there is no slack and the first movement of the cable moves the actuator arm.
It's common but wrong to adjust the pad clearance by adjusting the cable tension. Doing it that way is easier but sacrifices cable travel.

Paul Barnard

Larry is good. Not Ryan good, but can certainly set the hook.

BillyD

At least Ryan was entertaining.

couldwheels

Everything you said there is correct. But #2 requires special consideration.

There's a design flaw with many cheap mechanical disc brake calipers and that is the "triskelion" looking recess with three ball bearings driving the piston. The worst thing that could happen are the ball bearings spilling over the recess and falling to the adjacent recess.

If that happens, the piston retracts and you suddenly lose brake, whammy!! I bet this design flaw can fixed so easily by the designers by adding stops on the recess but unfortunately, the Chinese designers/engineers didn't. I have experienced this happening on two different looking brakes from different manufacturers but having the same piston drive mechanism.

It happens when the piston arm is pulled close to the limit or stops on the caliper (not on the brake lever). To prevent that from happening, the piston arm must be at or near the "unpulled" position when all the brake components has been fixed in place. The best way to do this is adjust the caliper housing so the side of the housing with the piston is as close as possible to the rotor. Note: it's the housing, not the brake pad.

When you adjust the caliper housing that way, the piston side brake pad would be adjusted near to the maximum unpulled position of the piston lever. There's no way the balls will leave their assigned recess and brakes operate safely enough. If not, then you'll also need to look for thicker brake pads or if your current pads are already worn, they need to be replaced immediately.

This is in fact your #1 priority when adjusting cheap mechanical brakes with such piston drive mechanism. It is far more important than eliminating loud squealing because it concerns safety.

couldwheels

Right. Big recreational riders should invest on better brakes.

Most commuters on dirt cheap bikes on dirt cheap brakes won't have safety issues because they're so slow, the saddle too low, they could just drag their shoes on the ground if they lost brakes and they would still stop on time because of their slow speeds.

vespasianus

Yea, I can't believe I fell for it!

The correct answer is to get cheap carbon tubular wheels to go with the cheapest disc brakes on your $150 bike so that you can find random women to draft behind!

BlazingPedals

Answers are good to keep for future searches. Yeah, it's lost on Larry.

rumrunn6

what brand & model?

wolfchild

If bike shops can not adjust your brakes it means that the brakes are low quality bottom of the barrel brakes which will never perform well no matter how much you adjust them. Maybe it is time to to upgrade your brakes to something better.

LarrySellerz

not sure, it was built out of spare parts by someone who knew what they were doing. I love it except for the brakes. The saddle cost more than the bike, was having some gentleman issues