Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Caliper Brakes will not fit through fork

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Caliper Brakes will not fit through fork

Old 12-16-12, 08:39 PM
  #1  
Jamse Meths
Newbie
Thread Starter
 
Join Date: Dec 2012
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Caliper Brakes will not fit through fork

Hey guys, this is my first post to these forums so please excuse my lack of correct terminology.

I have recently been building my own fixie out of an old Mountain Bike frame and have come across the problem that the axle that is suppose to be mounted through the forks on the new brakes i purchased is too short to reach through the other side. Is this normal and I'm just doing something wrong? And if it's not, can i buy a new longer axle that will fit or possibly drill a larger whole through the back of the mounting hole on the forks to fit the nut from back of the new brakes into? I apologize if this is confusing, just really need some help thanks! Also the brakes are Tektro R539s if that helps.
Jamse Meths is offline  
Old 12-16-12, 08:52 PM
  #2  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 35,964

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 124 Post(s)
Tagged: 1 Thread(s)
Quoted: 4361 Post(s)
Likes: 0
Liked 17 Times in 17 Posts
Caliper brakes are made for road forks and the bolt is often too short for the thicker (wider) crown on mtb forks. The easiest way to deal with this is to buy a nut of the kind used for recessed mount rod brakes. These come in various lengths, so you'll have no trouble finding one that works.

This sounds easy and it is, but there's a catch. The nuts have an 8mm diameter, so you'll need to drill the hole in the back of the fork out. You can use an 8mm drill, or a 5/16" which is close enough to match. Don't forget that you're only to drill the hole in the back of the crown. the front hole has to be left alone at 6mm.

If you can't or won't drill the fork, all is not lost. Buy a recessed nut, and a 6mm stainless steel cap screw the right length to reach close to the bolt but not actually reach it. Then cut the hex area off the nut to make a couppler.

You push the bake through, attached the coupler half way onto the bolt inside the fork, then put the cap screw through the back and tighten to the coupler. For this to work you want the coupler to be bout 5/8" and located so both the brake and screw have 5-6 threads engaged. (in case yyou haven't figured it out yet, this only works on forks where the steerer is open at the bottom.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Old 12-16-12, 08:56 PM
  #3  
jyl
Senior Member
 
jyl's Avatar
 
Join Date: Aug 2006
Location: Portland OR
Posts: 7,642

Bikes: 61 Bianchi Specialissima 71 Peugeot G50 7? P'geot PX10 74 Raleigh GranSport 75 P'geot UO8 78? Raleigh Team Pro 82 P'geot PSV 86 P'geot PX 91 Bridgestone MB0 92 B'stone XO1 97 Rans VRex 92 Cannondale R1000 94 B'stone MB5 97 Vitus 997

Mentioned: 140 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Likes: 0
Liked 41 Times in 26 Posts
Just a reminder, confirm that caliper has the proper reach (front and rear) before drilling anything. They look pretty long-reach but just check.
jyl is offline  
Old 12-16-12, 09:22 PM
  #4  
Jamse Meths
Newbie
Thread Starter
 
Join Date: Dec 2012
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Alright, i've also realised that the rear brake has the same problem and for the axle to fit through the brakes with both washers is only about a 5 mm gap and i don't see how i could possibly even fit a road bike frame inside 5 mm
Jamse Meths is offline  
Old 12-16-12, 09:31 PM
  #5  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 35,964

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 124 Post(s)
Tagged: 1 Thread(s)
Quoted: 4361 Post(s)
Likes: 0
Liked 17 Times in 17 Posts
It would've helped if you measured both bolts and posted the lengths. I suspect that you have recessed mount brakes which take nuts like these front and back.

If so, you may try this trick. Try the front brake (longer bolt) in the back, and see if the rear fits the front deep enough to enter the inside of the steerer by more than 6-8mm. If so, you can mount them that way using a super long nut or my coupler trick for the fork.

The other alternative is to look for brakes with standard (long)bolts. These are usually available in long reach versions, so it shouldn't bee too hard. But even then you may find that the front bolt is still too short, and need to drill the fork or use a coupler.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.

Last edited by FBinNY; 12-16-12 at 10:13 PM.
FBinNY is offline  
Old 12-17-12, 12:58 AM
  #6  
Jamse Meths
Newbie
Thread Starter
 
Join Date: Dec 2012
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
It's alright, i figured out i can switch the front and rear brakes around and run the short rear one through just one side of the front fork and the long front one at the rear easily enough! Thanks for your help though guys
Jamse Meths is offline  
Old 12-17-12, 06:18 PM
  #7  
FastJake
Constant tinkerer
 
FastJake's Avatar
 
Join Date: May 2010
Location: Madison, Wisconsin
Posts: 7,785
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 83 Post(s)
Liked 35 Times in 29 Posts
Originally Posted by Jamse Meths View Post
It's alright, i figured out i can switch the front and rear brakes around and run the short rear one through just one side of the front fork and the long front one at the rear easily enough! Thanks for your help though guys
So you're using the rear brake up front and just running it through the front hole of the fork? I think Sheldon Brown suggests this somewhere on his site but I don't know how you could keep the front brake from flexing under heavy braking.

If this works for you, make sure you get that thing bolted on REALLY tight. To me it doesn't seem like that great of an attachment for a front brake but I could be wrong.
FastJake is offline  
Old 12-17-12, 06:47 PM
  #8  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 35,964

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 124 Post(s)
Tagged: 1 Thread(s)
Quoted: 4361 Post(s)
Likes: 0
Liked 17 Times in 17 Posts
Originally Posted by FastJake View Post
So you're using the rear brake up front and just running it through the front hole of the fork? I think Sheldon Brown suggests this somewhere on his site but I don't know how you could keep the front brake from flexing under heavy braking.

If this works for you, make sure you get that thing bolted on REALLY tight. To me it doesn't seem like that great of an attachment for a front brake but I could be wrong.
There's nothing inherently wrong mounting a brake this way, since the flat area of the spring block holds the brake securely to the face of the fork.

The recessed nut can be attached in the middle of the tube and tightened through the back hole. The only issue is that the but is butting against the inside curve, and may bind before being truly tight. This is why I prefer improvising a coupler and using a bolt through the back. But an alternative might be to file a shaped spacer to fit inside the fork and make a flat spot for the nut to butt against.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
BrokenSproket
Bicycle Mechanics
18
10-31-16 10:19 AM
nextreme
Bicycle Mechanics
6
02-23-14 08:07 AM
fxkrait
Bicycle Mechanics
6
10-15-12 09:07 PM
sttlesks
Bicycle Mechanics
3
03-21-12 07:51 PM
mattkime
Classic & Vintage
8
06-19-11 09:15 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.