bigdufstuff

Hi,

I have a bianchi limited that has been converted to a fixed gear. Due to the age of the front brake, and some hard use, the brake busted apart on a ride.

I found some Shimano 105's on craiglist that I bought. I went to put the front brake on and quickly realized that it doesn't fit in the fork. The threaded bolt isn't long enough to reach through the fork, and the diameter of the "nut" to reach the bolt is too large to fit inside the fork.

Do I need to buy special brakes to fit my fork? Is there there a way I can salvage these brakes or should I just sell them and look for something different.

BikingGrad80

Sounds like you are trying to put a rear caliper up front. Rear calipers have shorter bolts than fronts.

bigdufstuff

I am not at home so I can't confirm this, but I don't think this is the case. There is one caliper with a VERY short bolt, and one with a not quite so short bolt. I am trying to use the one with the not quite as short bolt.

It looks like it was designed so that the bolt only goes half way through the fork and the "nut" (which has quite a bit of reach to it) was designed to meet that bolt halfway. However on my fork there the hole is too small in diameter to all the bolt inside.

Was this a general design change in how calipers attach to forks? On my old brake, the bolt went clear through both sides of the fork and there was a nut on each side to secure it to the fork.

Adohrn

You probably have an external nut to secure the brakes, not the newer recessed hex nut. This guy will show you how to deal with it.
https://www.bikeforums.net/classic-vintage/327221-my-miyata-610-a.html

bigdufstuff

Adohrn, that is exactly my problem.

I was hoping it wouldn't come to cutting up my bike, but looks like it will. I'll see what I can do. Thanks for the link.

Do calipers still exist that will work with my bike? I guess I'm looking for advice on whether I should go through the trouble of dremeling the fork, or buy different brakes. (and then sell the 105's).

Sheldon Brown

First, make sure the reach is OK. See: https://sheldonbrown.com/reach

If so, see: https://sheldonbrown.com/recessed

Sheldon "Stop!" Brown

Adohrn

My best guess would be no newer quality calipers would have and external nut. Ebay for older style calipers would be an option. The 105’s are also probably dual pivot which are better brakes

Adohrn

The expert has responded.

bigdufstuff

Thanks Sheldon!

I'll look into the reach once I get home and then give the drilling/dremeling a shot.

HillRider

To adapt an older external nut fork to the newer recessed nut type you have to drill out the rear face (ONLY the rear face!) of the fork crown's existing 6 mm hole to 8 mm (a 5/16" bit also works). This is easy since the existing hole will guide the larger drill bit.

matimeo

+1 This is exactly what I had to do to put some 105 brakes on a Nishiki from 1983. When drilling out the rear face, be as careful as you can to drill it straight or you might have some problems with the brakes setting sort of sideways.

Mr Pantani

Dang, I never thought of drilling. I have a pair of brand new recessed-style Tektro calipers sitting in my parts bin that I had to abandon when I realized my Nikishi used external-nut calipers. Cool.