KHO

I am new to the forum so i can't post pictures yet but i have a question about how to align brake pad on cheap components.


I do some bike repair on the side as a kind of hobby. I have a fair amount of regular customers that I do tune ups for. It is mostly casual riders. When I have a new customers they generally bring in barn fresh bikes that they want to start riding again. So in comes the Trek Shift 3 bike with Tektro alloy linear-pull brakes. The brakes are very cheap, but they are about as good as they where when they were new. First I tried adjusting the cable but found the that I had to really open the brakes up to get the brakes not to rub and the lever was close to bottoming out on the grip. The wheel is true to within a 1mm. As i start to check the centering of the brake I noticed the pads are not lined up properly with the rim. As I fix that i notice two things. 1) to align the pad with the rim i have to set the brake pad post to the extreme lowest position. 2) The pad also has severe toeing in the wrong direction . The pad has conical washers but even when loosened and adjusted to the maximum toe in the washers allowed, the pads still are toed in the wrong direction. I couldn't even achieve parallel pads with the rim.


What i did to fix this situation was to just slightly bend the pads to the proper adjustment.

next time this happens should i do the same thing? or is there a better procedure to fixing this issue?


Thanks for your feedback

bboy314

I would check that the right size wheel is installed, and whether the brake arms or fork (assuming front brake) are bent. Also make sure the concave washers are installed in the correct order.

KHO

This was happening on both front and rear brakes. The wheels where the original wheels. I didn't notice anything weird with the washers but i will need to confirm that next time.

Thanks! @bboy314

grumpus

Two things to check:
• Spherical washers are assembled in the correct order and orientation so they can actually work as intended.
• Brake bosses are parallel as seen from above, to give the brake arms a chance of adjusting properly.
But beyond that, with cheap components sometimes the best you can manage is to persuade them into the right sort of shape with whatever implement does the job - often a crescent wrench. Once you've done this the fix should be permanent, so not too worrying that you've bent aluminium parts, but do be careful to only bend as much as necessary.

KHO

thanks! Grumps

next time I will need to double check the washer order

oldbobcat

If I had a nickel for every home mechanic who messed up the order and orientation of those spherical washers, I could buy coffee for the entire forum. Once you get that right, I find that orienting the pad with a matchbook cover or rubber band between the rear of the pad and the rim gives just the right amount of toe-in.

What's a matchbook cover, you might ask. Ask your grandpa.