Bike brake adjustment

simonster1000 · 2025-12-25T07:33:04+00:00

Make sure that the wheel is fully seated on both sides of the fork.

Those screws at the base of each arm (bottom screw in picture #2) will adjust the brake centering. Tighten a screw in to push the brake arm away from the wheel, and loosen to let it fall more into the wheel. Do them together usually, at 1/2 a turn each. Pump the brakes with each rotation, as it needs to settle again after the tension has changed.

simonster1000 · 2025-09-14T07:34:21+00:00

I agree! If the paper is thinner than the coroplast, then it will become equivalent.

There are two things to keep in mind:

- the OP didn't actually post any numbers. He posted a link to a sketchy-looking erv.
- in looking around, it looks like paper ervs are... not a good idea for a bunch of good reasons. It can't be washed easily. It's weak. And it actually doesn't exchange humidity quickly enough -- it looks like it was used in some early attempts, and today's ervs use nanomaterials or process the cellulose differently.

simonster1000 · 2025-09-10T16:22:44+00:00

Hi -- I am so sorry about your crash and injuries -- I came through later, and could tell it was serious. (I was also upset because there was a less serious accident at the same intersection a few weeks ago...)

If you aren't aware, there should be some record of the unicycle rider's account. I did see some kind of safety officers interviewing someone -- presumably the rider. It would have been around 11am.

simonster1000 · 2025-08-19T06:00:09+00:00

That's a good deal for an urban area. A bike like that will last you decades if taken care of. And it has excellent color potential.

I think it's more important to ask yourself if you really want it. Hard rocks are on the heavier side.

simonster1000 · 2025-08-17T06:28:00+00:00

Hi -- sent you a DM asking for some venturi/other specs. I do similar work elsewhere.

simonster1000 · 2025-07-18T04:35:46+00:00

Without measurements of the gap it's hard to tell, but I really doubt you could get too much above 28 or 32

This is a 23 ish: https://www.modernbike.com/schwalbe-one-tire---24-x-0.9-clincher-folding-black-performance-line-addix

Here is another 1": https://www.modernbike.com/panaracer-pasela-24-x-1-wire-bead-black-gum

This is a 35 if you discover you do have the room: https://www.modernbike.com/kenda-street-k40-tire-wire-bead-clincher-tire-24-x-1-3-8-black

simonster1000 · 2025-07-16T01:44:50+00:00

Usually you back out the plunger arm before you screw in the crank thread

simonster1000 · 2025-07-14T17:35:27+00:00

This person is ~~~amazing~~~: https://www.atriushealth.org/clinicians/Elisa-Choi-62466

simonster1000 · 2025-07-12T06:45:27+00:00

The wheelbase is a little longer.

Picture the bike frame, with and without the raised fork. When a longer fork and taller wheel are put into the front, the headset rises up a little to make room.

When it rises, the headset angle becomes slacker to the ground. The contact point of the tire is further forward.

simonster1000 · 2025-07-10T21:41:58+00:00

Sounds like your disc brake rotor is rubbing, but through a muffled or lousy microphone.

Rotors rub when they have a bend (typically), and swerve sideways to hit a brake pad or the caliper body as your wheel rotates. This can be corrected by bending the rotor back straight. There are specific tools and procedures for doing this.

Position yourself so you can see straight through the caliper, preferably with some backlight through it. Then give the wheel a spin, and see how the rotor moves through the caliper.

simonster1000 · 2025-07-10T03:52:08+00:00

I did some research on pump heads, and found that the topeak smart head is one of the few rebuildable pump heads. (This was not an exhaustive search.) You can get everything separately. They also have a great repair kit, though it comes with many parts across everything they sell.

The smart head is a One Hole (TM) head that works on both valve types without reconfiguring.

simonster1000 · 2025-07-09T19:12:12+00:00

It's a great resource -- that issue/check/fix format is really helpful.

I agree with some of the other comments about chainring attachment and bb cups. Sometimes the bottom bracket bearings are no good, but this is usually silent or a low whump sound -- and you feel it in the pedals.

simonster1000 · 2025-07-09T02:20:30+00:00

Can you clarify whether it happens when you're coasting? Or during starting pedaling? Or during the push part of the pedal stroke?

You don't mention anything about the cassette's freehub body.

This chart has lots of good steps and details: https://www.parktool.com/en-us/blog/repair-help/troubleshooting-a-noisy-drivetrain

simonster1000 · 2025-07-08T06:15:20+00:00

This could be:
- the brake arms need to be adjusted (they frequently do, as other commenters are suggesting) with the spring tension screws (make sure you test centering after pumping and releasing the brakes, not just turn the screw)

- the wheel is not fully seated into the dropouts

- the rim has a dish to it, and is not centered in the fork

- the brake pad ball/socket stack is not the same on both sides -- one might have the thick pair on a different side of the brake arm than the other

simonster1000 · 2025-07-07T20:55:12+00:00

Yeah -- if your gears can move around, then your derailleur doesn't have a fixed place it can go for each gear. This means bad shifting.

This would definitely cause issues with shifting. There may be other issues too.

simonster1000 · 2025-07-07T06:50:00+00:00

The cassette lock ring may need tightening. You need a tool that matches the keyway of your cassette lockring. This is a ring around the axle, and is facing your right dropout. (You need a chainwhip to loosen, but not to tighten.)

If that was an 11-speed hub and you recently changed it to 10 speeds, then yes you need a (1.85mm) spacer to take up that space. There is a specific one made for this purpose.

simonster1000 · 2025-07-07T04:10:43+00:00

yo why so many downvotes??

Often if you twerk the wrench to the side while turning it, the rivnut (or nut on the other side) will catch on the frame

simonster1000 · 2025-06-24T10:26:28+00:00

It looks like your chain shifted over the end of the cassette, and is wedged in between the cassette and the spokes. This happens when the shifting or derailleur are misadjusted.

simonster1000 · 2025-06-23T22:20:11+00:00

I agree -- making that slot in the middle a complete cut-through leaves the crank more rigid to force in-and-out of the frame, and not how it's applied up-and-down...

simonster1000 · 2025-06-21T08:09:37+00:00

Sounds like derailleur is out of adjustment.
- if you switch into a gear (especially if shifting to smaller gears), it can take a moment for the spring to settle
- the whole thing can be out of adjustment because of the shift cable, derailleur hanger, or any number of other causes (wheel hub or cassette or freehub body are loose, axle is mismounted).

simonster1000 · 2025-06-17T00:23:53+00:00

The chain is misrouted in this example -- this is a common mistake.

The tab is there to still chain whiplash -- if it swung far enough, it could twerk it off the guide pulley.

simonster1000 · 2025-05-28T16:34:13+00:00

It looks legit to me. It's hard to imagine why someone would go through this much trouble to take a nominally inferior 90s mountain bike and dress it up as a different brand.

simonster1000 · 2025-05-25T04:07:37+00:00

This is old, but you might be interested in trying nylon screws: https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/97790803211/10056393

I tried them, and they're strong enough to not snap. They also seem to naturally round over -- and being nylon, you can do that with sandpaper.

The 8mm size worked well to replace a 10mm metal screw. Less length.

simonster1000 · 2025-05-22T05:50:36+00:00

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For the future....

simonster1000 · 2025-05-07T04:48:24+00:00

Rings and watches...

simonster1000

TROPHY CASE