Retrobike Forum Index

It is currently Sat Dec 10, 2016 11:47 am

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Fri Feb 01, 2013 10:48 pm 
Retro Guru

Joined: Tue Dec 21, 2010 6:31 pm
Posts: 1112
Hey,

I'm restoring a post-war bike with cantilever brakes. One of the canti bosses was broken and
has been cut down, as you can see in the attached picture. Also, I think the bosses are not
straight/parallel. I took a few pictures of this, but it's not easy to see in pictures.

Can anyone advise on what to do? So far, my options seem to be:

1) Drill/tap a hole in what's left of the boss and use a bolt to fix on the canti - this seems to be
how the 'Problem Solvers' canti repair kit works. This doesn't solve the problem of the
bosses not quite being straight, though.

2) Have new canti bosses brazed on. The only problem is that the diameter of the existing
stud is about 1mm bigger than a normal canti stud - could I use a shim of some sort to fix this?
It seems Bob Jackson charges about £15 for brazing a canti boss on, so it doesn't seem to be
took expensive.

I would like to rescue the fork and keep the cantis if at all possible since they are both original to the
bike and quite distinctive and interesting.

Thanks for any advice.

Johnny


Attachments:
JRCFork.jpg
JRCFork.jpg [ 314.35 KiB | Viewed 174 times ]
Top
 Profile  
 
PostPosted: Sun Feb 03, 2013 5:43 pm 
Retro Guru
User avatar

Joined: Mon Sep 24, 2012 9:10 pm
Posts: 669
Assume the broken part is a threaded part of the boss itself? i.e. this is a 'stud' with a domed nut rather than a bolt with a domed head? Could you not drill/tap, manufacture a stud, and then get a framebuilder to rebraze the bosses on straight? Possibly getting the new stud brazed to the boss at the same time.


Top
 Profile  
 
PostPosted: Sun Feb 03, 2013 11:13 pm 
Retro Guru

Joined: Tue Dec 21, 2010 6:31 pm
Posts: 1112
Yes, the brake arm is held onto the boss by a nut that fits a threaded bolt that's part of the boss.
So your solution seems much better than mine - I presume I would need to braze a
piece of steel rod into the broken boss then cut a thread onto it with a die.

Cheers for the help!

Johnny


Top
 Profile  
 
PostPosted: Mon Feb 04, 2013 12:07 pm 
Retro Guru
User avatar

Joined: Mon Sep 24, 2012 9:10 pm
Posts: 669
My first thoght was to drill the boss and tap the resulting hole, which is probably not necessary..you may find an old bolt or stud with the right thread that will do the job... If you can you won't need a die. Just drill an accurate hole in the boss into which you can braze the stud. I'm no authority..just thought someone should answer your post!


Top
 Profile  
 
PostPosted: Mon Feb 04, 2013 8:32 pm 
Retro Guru

Joined: Tue Dec 21, 2010 6:31 pm
Posts: 1112
Yes, I was wondering if a threaded bolt might be stronger than just brazing a rod in.
In any case, I've been in contact with a frame builder here in Belgium who'll have a look and
see what he thinks.

Johnny


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: Bing [Bot] and 37 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group