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

Figuring out these canti doohickeys! (help please!)

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.

Figuring out these canti doohickeys! (help please!)

Old 06-17-10, 11:34 PM
  #1  
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Posts: 20,247
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Figuring out these canti doohickeys! (help please!)

I'm building up an 84 Trek 520 as a commuter and I bought some Tektro 720's for it since the brakes that came with the bike are completely disassembled and look like a nightmare to set up and keep working (dia compes). The other set, some shimano exage brakes have a set of springs that is messed up. I could probably do one of each, but I like working brakes...

So I bought the Tektros after reading good things about them. I've installed canti's before, but this time things are weird. I tightened up the bolt and I feel some side to side play in the brakes. Not something that should be there right?

I tried putting a spacer in there, but then the brake won't return properly.

Has anyone ever encountered this? What should I do?

Please help! Thanks!
ridethecliche is offline  
Old 06-17-10, 11:48 PM
  #2  
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Posts: 5,466

Bikes: Norco (2), Miyata, Canondale, Soma, Redline

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
There SHOULD be a little play in the arms. They don't fit 100% tight to the bushings. And keep in mind that when you tighten the screw that you're tightening the inner fixed bushing to the post and that the brake does not pivot on the post. It pivots on the bushing that you clamped to the post with that screw. So you don't want to use a spacer since that'll close up the required free play that the arms need to have.
BCRider is offline  
Old 06-18-10, 12:15 AM
  #3  
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Posts: 20,247
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
I didn't notice this on the last set of cantis I installed.

Like there's visible play in there. It feels like a loose tooth wiggling back and forth. As in, the entire assembly is moving side to side. I wouldn't say that this is a 'hair' of play.
ridethecliche is offline  
Old 06-18-10, 12:24 AM
  #4  
Torchy McFlux
Senior Member
 
Torchy McFlux's Avatar
 
Join Date: Sep 2007
Location: Vancouver
Posts: 1,438

Bikes: NOYB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
So the brake is ratting around on the braze-on post? Sliding back and forth?
Did you grease the post and bushing (if there is one) before installing? All the washers included with the brake were used?
Torchy McFlux is offline  
Old 06-18-10, 07:25 AM
  #5  
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Posts: 20,247
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
There was only one washer included with the brakes and that was the one that goes on the bolt attaching the brake. That one stayed on.

It goes: spring-->Canti arm-->bolt with small spacer.

With this setup, the brake moves back and forth slightly on the post. I can't figure out how to stop this.
ridethecliche is offline  
Old 06-18-10, 10:07 AM
  #6  
Phil_gretz
Journeyman Bike Commuter
 
Phil_gretz's Avatar
 
Join Date: Aug 2009
Location: Alexandria, VA
Posts: 4,780

Bikes: '78 Motobecane Grand Jubile, '79 Peugeot PXN10LE, '88 Fuji Saratoga, '12 Jamis Sputnik, '13 Motobecane Fantom29 HT, '16 Motobecane Turino Pro Disc, '16 Motobecane Gran Premio Elite

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 458 Post(s)
Originally Posted by ridethecliche View Post
I'm building up an 84 Trek 520 as a commuter and I bought some Tektro 720's for it since the brakes that came with the bike are completely disassembled and look like a nightmare to set up and keep working (dia compes). The other set, some shimano exage brakes have a set of springs that is messed up. I could probably do one of each, but I like working brakes...

So I bought the Tektros after reading good things about them. I've installed canti's before, but this time things are weird. I tightened up the bolt and I feel some side to side play in the brakes. Not something that should be there right?

I tried putting a spacer in there, but then the brake won't return properly.

Has anyone ever encountered this? What should I do?

Please help! Thanks!
My advice would be to go back to the DiaCompe cantilevers. Why? They're set up properly for the cantilever posts, brake lever mechanical advantage and wheel dimensions with which your bike came. I'm assuming that they're 821s or something similar. The brake pads can be changed to a more modern material (koolstop dual compound or salmons) for improved performance.

I had the same issue with an older Fuji I have, and after learning how to adjust the DiaComps properly, have adequate braking for loaded touring. YOu have to be patient.

My two centavos...
Phil_gretz is offline  
Old 06-18-10, 01:18 PM
  #7  
goatalope
Biking Viking.
 
goatalope's Avatar
 
Join Date: Nov 2007
Location: Camp Hill, PA
Posts: 345

Bikes: '01 Lemond Buenos Aires, '11 Specialized Stumpjumper FSR, 70s Austro Daimler Inter 10, 80s Motobecane Mirage 10 Fixed Gear

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Get more washers?
goatalope is offline  
Old 06-18-10, 02:54 PM
  #8  
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Posts: 5,466

Bikes: Norco (2), Miyata, Canondale, Soma, Redline

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Pull the screw and end washer off and look to see that the brake's inner bushing is sitting up very slightly higher than the end of the post. If by some chance your mounting post is a hair longer than the arm's bushing then it won't tighten up. If so then it's kosher to use a spacer but be sure it doesn't flex and cup over so it drags on the arm. It'll also needs to be a spacer that has a hole that is larger than the post but only barely. Otherwise it may not rest securely against the inner bushing. If you just used a generic washer with too big a hole it may have tightened up off center and that's what caused the drag.

Or it may be something else all together. But hopefully all this and the stuff from the other folks has given you some ideas on how to look at it and analyze what the issue is and what to do to fix it.
BCRider is offline  
Old 06-19-10, 12:50 PM
  #9  
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Posts: 20,247
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Using the spacer didn't work because tightening it just led to the brake being too tight on there or still moving too freely. If I could remove the spacer on the screw and put it back in, it would work, but the original spacer on the screw can't be taken off...

I left the bike at a shop with the original brakes so the mechanic can put them together. I'll go there on monday and see what ended up happening.

The dia compe's with salmon pads will probably work fine. Or I have some shimano exage canti's that might work fine. Lets see.
ridethecliche is offline  

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

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