submitted 4 months ago* (last edited 4 months ago) by evasync@lemmy.world to c/bikewrench@lemmy.world

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I had some wheel made but when they rotate they come in contact with the disc break pads (slightly).

The bikeshop that built them will take another month to look at this, as they are fully booked, and I dont want to pay 35+ on another bikeshop..

Is it doable to DIY this with a spoke key and using the fork as a stand?

(I think it would be a useful skill to learn as it will make me less dependent on bikeshops)

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[-] j4k3@lemmy.world 10 points 4 months ago

Disc brakes should not be affected by wheel truing. Those are not related problems. If you have rim brakes then it will be an issue, but not discs.

Truing wheels is not hard. A bike stand helps a while lot. I build and true my own wheels on the bike, with the bike in a portable stand.

Disc brake problems can be tricky. The disc itself can be trued with bending.

[-] evasync@lemmy.world 2 points 4 months ago

If wheel wobbles wouldnt that also make the disc wobble?

[-] j4k3@lemmy.world 7 points 4 months ago

The rim is positioned by the spokes, but the hub is constrained by the bearings and dropouts. It is a rigid member. The rotor disc is attached to the hub directly.

Disc brakes are not easy to setup and get them right. I'm a hardcore roadie from back before disc brakes were a thing for road. I also have a top shelf mountain enduro bike that has disc brakes. While I work on all of my own road stuff, I avoid working on fork/shock internals and disc brakes. I've worked in several bike shops and I always pay the mechanics to setup my disc brakes. I've learned the hard way of having the annoying things make tons of noise and problems.

There is a Park Tool rotor truing tool that they use to tweak the positioning of the rotor by bending it slightly. It is difficult to tweak them right without making the problem worse. Here is the tool used with a special jig on a truing stand that allows more accurate adjustment without turning the thing into a wavy piece of junk:

[-] Thorny_Insight@lemm.ee 4 points 4 months ago* (last edited 4 months ago)

Truing the wheel has no effect on your brake rotor rubbing the pads. You have a bent dics. You can straighten it using an adjustable wrench. Just make sure it's clean so that you don't contaminate the brakes. If it's rubbing all the time and not just at certain point then your calipers might be out of alignment or your wheel is not seated properly

[-] evasync@lemmy.world 1 points 4 months ago* (last edited 4 months ago)

If there is a side wobble in the wheel and the discs are attached to the wheel, wouldnt that make the disc wobble? And if the disc wobbles, couldnt that make it rub to thr break pad?

(Also he discs are brand new and not look bend at all but not sureidf i can tell just by looking at it)

[-] Thorny_Insight@lemm.ee 2 points 4 months ago* (last edited 4 months ago)

No, the disc is attached to the wheel hub. Wobble on the rim has no effect on the brakes. If it was a road bike with rim brakes then it would but not with disc brakes.

If you rotate the wheel and look thru the brake caliper you can see which part of the disc rubs and which side. Put adjustable wrench on that part and bend it to the opposite direction and check again. It's pretty easy to straighten. I've had that happen on relatively new discs as well.

Here's a good tutorial

[-] litchralee@sh.itjust.works 4 points 4 months ago* (last edited 4 months ago)

I am not an expert bike mechanic by any means. With that said, I can't quite visualize how re-truing the whole wheel will address a rotor rubbing issue.

The rotor mounts onto the hub at one of the most durable parts of the assembly, adjacent to the bearings. Generally speaking, the act of truing a wheel is to manipulate the rim so its axis of rotation matches the axis of the hub, where the spokes pull the rim into submission. This process shouldn't affect the rotor, since that would suggest the hub itself is not spinning true; that could indicate an outright defective hub.

Are you able to confirm that the disc rotors are true? If the shop built and delivered the wheel with the rotor attached, presumably they checked both rim and rotor for trueness. But if you installed the rotor yourself, you might need to true the rotor.

If the rotor is true and the whole wheel is true, then that just leaves the brake pads and calipers, which could be misaligned. Although I'm not sure how this would look.

this post was submitted on 21 Jun 2024

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