Why two washers on rear brakes?

[Derosid]

I have a new set of Campy brake calipers that I am mounting, and the rears came with 2 of the toothed mounting washers. The bolt on the brakes is too long to only use 1 washer.

Is there a reason not to just cut the mounting bolt slightly shorter and use a single washer for the rear brake?

[AngryScientist]

On some frames you need the standoff provided by two washers to prevent the pads from hitting the seatstays...

[bikinchris]

Originally Posted by AngryScientist

On some frames you need the standoff provided by two washers to prevent the pads from hitting the seatstays...

This

[J.kovak]

I actually have to use 3 on the rear of my terraplane Kirk 😁.

[camelbackkid]

I believe on the front the extra washer increases tire clearance, and on the rear it adds clearance to the seat stays.

[oldpotatoe]

Originally Posted by Derosid

I have a new set of Campy brake calipers that I am mounting, and the rears came with 2 of the toothed mounting washers. The bolt on the brakes is too long to only use 1 washer.

Is there a reason not to just cut the mounting bolt slightly shorter and use a single washer for the rear brake?

Why on earth would you permanently alter the brake bolt and not just use 2 washers? As has been mentioned, some frame rear brazens are thick enough to need only one washer.

[Derosid]

Originally Posted by oldpotatoe

Why on earth would you permanently alter the brake bolt and not just use 2 washers? As has been mentioned, some frame rear brazens are thick enough to need only one washer.

Stacking 2 toothed washers seems like it would be unstable, and cutting a bolt and chasing the threads is trivial. With that being said, I’ve never noticed a downside to the stacked washers, I just wanted to know if there is something I was missing.

[Blown Reek]

Two washers doesn't make the rear brake unstable at all, but feel free to cut away.

[duff_duffy]

For the engineers in the group does a stacked setup increase some friction coefficient between nuts and bolts in some way? I thought I read somewhere the double washer set up is better than a single larger washer as well.