5

Just bought a used bike- it's great, but needed new brake pads. Got new brake pads and now the tire is rubbing on the brake arm. I do not understand! The front brake is with new brake pads is the same make/model and is amazing in every way. Is there a solution to thin? Is there something about brakes I don't know??? The tire is 700c x 25mm

2005 Trek 1500 WSD

tire rubbing on brake arm

enter image description here

  • 3
    Basically, the tire is too big. – Daniel R Hicks May 1 at 21:54
  • The bike is built for 25 mm tires. Those look to be larger -- maybe 32. – Daniel R Hicks May 1 at 21:55
  • 2
    (Did you remove the wheel at some point, and is it possible you don't have it drawn all the way back in the dropouts?) – Daniel R Hicks May 1 at 21:58
  • The tires are definitely 25mm wide! So confusing – BrianN May 2 at 1:00
  • 2
    In 2005 23mm was the standard and tight clearances fashionable. Besides, this is about tire height so thinner tread might help. – ojs May 2 at 6:37
4

It looks like your new brake pads have pushed the right brake arm out moving the top of the arm down, touching the tire. You need the top of the brake arm to move up and give you some clearance.

Options

  • Get thinner brake pads
  • Cut the new brake pad down some so that it will be thinner
  • If there are any washers between the back of the brake pad and the brake arm remove them (I can't tell from the picture)

Hopefully all you need to do is remove some washers.

  • 6
    The brake pivot is directly in the center of the brake arm, centered over the tire. Adjusting the pad thickness will do little to change the situation. – Daniel R Hicks May 1 at 21:57
  • 1
    I may be wrong. According to the story all that's changed is the pads. If that's the case then the tire worked with the old pads. – David D May 1 at 22:28
  • 3
    @DanielRHicks on many calipers the pivot is on the opposite side to the cable, see this parktool.com/assets/img/repairhelp/ident_dualpivot.jpg – Argenti Apparatus May 1 at 22:32
  • 1
    The pad on the right hand side of the picture seems to be mounted significantly higher than that on the left. It may not be positioned incorrectly and that is what is pushing the caliper arm I outward – Argenti Apparatus May 1 at 22:37
  • 2
    You were correct. The washers were thicker than needed to be, so once they were removed the tire has a millimeter or two of clearance, now! Sanding down the brake pads would also work, but it's just such a stupid problem! Gah! Will have to look into getting a new brakes, eventually. Until then, this will be fine. Thanks!!!! – BrianN May 3 at 15:04
3

If you was to remove the pads would you get sufficient clearance on the centre?

If so get thinner but longer pad blocks.

They look to be a fairly chunky pad block but it could be the angle of the image playing with my eyes.

2

I have a 28mm tyre on a bike that should max out at 25mm. Its a really close fit, and I have a similar problem to you when the brake quick release is open - namely when the brake pads are further apart, your brake arms are wider and the metal up near the pivot point is in a different place.

In your case the new unworn pads are thicker and pushing the arms apart, eating up the last millimetres of clearance.

The proper fix would be to put a smaller tyre on, but that's annoying.

In my case I ended up filing the center of my brand new tyre where the mold join lines were, which gave more clearance.

In your case, look at your brake pads and see if you can swap around or remove some washers. The Drive Side brake pad holder seems different height to the left one, but that could be an artefact of the carpet pattern in the background.

Another option is to add some wear to the brake pads with a file, to provide a little more clearance. You might want to buy some thinner low-profile pads for the back wheel and save those ones for the front wheel where you're not having any problems.

1

In relation to David D.'s answer and Daniel R. Hick's comment, it's most likely both.

If your dropouts look like this:

enter image description here

The tyre size is too big, but the old, thin pads made it look and feel like it fitted.

It's either you slice your newly bought brake pads thin and be done with it or think long-term and replace it with an actually proper-fitting tyre.

BUT,

if your dropouts are the horizontal/angled/adjustable ones, like these:

enter image description here

then you might wanna adjust your wheel axle to the back just a bit.

  • 1
    The model is listed in the question as a Trek 1500 WSD which appears to have vertical dropouts. But then your suggestion could apply to other readers in the future with different bikes looking for similar help. – Swifty May 13 at 10:21
0

Did you remove the wheel to install the new brake pads? Maybe now the wheel is in a different position.

To correct this, the wheel needs to be pushed slightly down, while closing the skewer lever. Just check that the nut is not massively out of the dropout.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.