Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-26-08, 05:28 PM   #1
intence
Senior Member
Thread Starter
 
Join Date: May 2005
Bikes:
Posts: 1,307
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Mounting brakes on a road bike

I'm in the middle of doing my first build of a road bike, i'm trying to mount stock Shimano Ultegra 6600 brakes on the bike, but it appears that the stock brake bolts that came with the brakes are too short too mount the rear brake ... Is this somewhat common? Do I just need a longer bolt for the rear, or am I doing something wrong?
intence is offline   Reply With Quote
Old 09-26-08, 06:05 PM   #2
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It would be uncommon, but if you're sure the recessed bolt isn't long enough - your LBS should stock longer ones. They come in various sizes.
operator is offline   Reply With Quote
Old 09-26-08, 06:20 PM   #3
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Bikes: Norco (2), Miyata, Canondale, Soma, Redline
Posts: 5,456
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Is this an older frame? Is the rear tubular nut going down into the brake bridge or is it just on the surface? If the hole on the front side of the brake bridge isn't big enough to let the shank of the tubular nut fit into the tube then you'll need to drill that out. This is a tough one due to restricted access in the opening and the topic of many a past thread.
BCRider is offline   Reply With Quote
Old 09-26-08, 06:43 PM   #4
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by BCRider View Post
Is this an older frame? Is the rear tubular nut going down into the brake bridge or is it just on the surface? If the hole on the front side of the brake bridge isn't big enough to let the shank of the tubular nut fit into the tube then you'll need to drill that out. This is a tough one due to restricted access in the opening and the topic of many a past thread.
He said it was too short, not that it didn't fit IINM.
operator is offline   Reply With Quote
Old 09-26-08, 10:36 PM   #5
Joshua A.C. New
Senior Member
 
Joshua A.C. New's Avatar
 
Join Date: Aug 2007
Location: Northampton, MA
Bikes: Iron Monkey: a junkyard steel 26" slick-tired city bike. Grey Fox: A Trek 7x00 frame, painted, with everything built, from spokes up. Jet Jaguar: A 92 Cannondale R900 frame, powder coated matte black with red and aluminum highlights.
Posts: 956
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Are you sure you don't have your brakes reversed front to back?
Joshua A.C. New is offline   Reply With Quote
Old 09-27-08, 01:27 AM   #6
intence
Senior Member
Thread Starter
 
Join Date: May 2005
Bikes:
Posts: 1,307
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The longer bolt goes in front right

The frame is fairly new (2007 Trek 2100, one of the last US made Aluminum trek's I believe). The rear seatstays including the wishbone area are CF, so it's pretty thick (about 35mm total thickness). As far as I can tell, I can't get the flared allen-key end of the nut to fit into the hole, so my only other option would be to get a longer brake nut?

Looking at my other bike with Aluminum stays, the distance is much shorter, so i'm assuming it's the thick wishbone area of the carbon stays that's causing the problem. Does this sound right? The frame is anything exotic, which is why i'm wondering if this is a common issue.
intence is offline   Reply With Quote
Old 09-27-08, 11:34 AM   #7
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Bikes: Norco (2), Miyata, Canondale, Soma, Redline
Posts: 5,456
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
So the issue is that the head (not a flare) of the nut won't fit down into the hole. OK.

Is there a shoulder down inside the recess in the bridge that the head would rest on? If not then the nut is intended to have the head stay out and exposed. If there is a shoulder in the hole then the head of the nut is just a little oversized and you can fix that by mounting it in a hand drill and hold a metal file up to the head to slightly reduce the diameter until it does fit.

But from what you're saying I get the impression that the nut isn't threading onto the caliper's bolt at all. That's a whole other issue. In total you must have the nut thread onto the bolt by at least 5 turns. And even at that I'd be looking for a longer nut that provides more like 6 to 7 with 8 turns being even better. If it's not even hitting the threads or is only turning on a thread or two you'll need to look in the hole and evaulate how many more turns you'll get by reducing the head diameter if it has a shoulder inside to seat onto.

Lots of "if"s but hopefully that'll help you out. They make the holes in the frames pretty tight. If you're running with a higher end Campy or Shimano brake the tubular nuts were finely made to tighter tolerances. I've seen some that look like they came from the high end aerospace industry and others that look like they were whittled out from a bar of soap and then half melted to smoothen them up. The chromed ones in particular can be pretty cheezy looking and I can see one of those not fitting properly quite easily.
BCRider is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 02:45 AM.