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


Go Back   > >

Singlespeed & Fixed Gear "I still feel that variable gears are only for people over forty-five. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailer? We are getting soft...As for me, give me a fixed gear!"-- Henri Desgrange (31 January 1865 - 16 August 1940)

User Tag List

Reply
 
Thread Tools Search this Thread
Old 02-12-05, 01:11 PM   #1
RobbieIG
Postmodern Beauty King
Thread Starter
 
Join Date: Oct 2004
Location: Corvallis, OR
Bikes: Centurion Fix, Jamis Nova, Jamis Crosscountry
Posts: 154
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Rubbing Potential...What to do?

Posted a similar question in the mechanics forum...didn't really find the response I was looking for.

A while ago, after I had been riding my Le Tour fixed conversion, I started looking for some upgrades I could make, and I found a good deal on a Centurion frame. I took the guys word when he said he had been running 700x35 tires in the frame and because of the perticulars of the situation, I purchased the frame without doing any measurements myself.

This is a picture of a cold 700x28 and the rear brake mount.



It doesn't rub, but it gets real close about 2mm at max >1mm at min. Not something I feel comfterable with. This frame is deffinetly designed for 700c wheels, and with a 700x28 the front fork still has ample clearance. I don't need to run a rear brake, but I wouldn't mind leaving the option there.

In your vast library of experience, is there anything to be done? I think I would be in danger of flats is I go smaller than 700x28 due to my body and cargo weight. Can that cross piece be removed from the seat stays?

Do I need to just learn my lesson from the purchase and move on?

Why would the stock front fork have so much clearance and the rear have so little?

More Pics:

RobbieIG is offline   Reply With Quote
Old 02-12-05, 01:22 PM   #2
gally99
cripple
 
gally99's Avatar
 
Join Date: Jul 2003
Location: all up in ya grill...
Bikes:
Posts: 467
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
you should still be able to run a brake if it's on the slim side... i don't see what the problem is...
gally99 is offline   Reply With Quote
Old 02-12-05, 01:55 PM   #3
dolface
Iguana Subsystem
 
dolface's Avatar
 
Join Date: Nov 2004
Location: san francisco
Bikes:
Posts: 4,016
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i have the exact same bike (albeit w/ gears on it) and i run 700 x 25, which isn't really applicaable your situation.

BUT, the bike was originally sold as a high-end tri bike, so i'd be really surprised if you could get a 700 x 35 0n there.

that being said, i don't think there's any reson you couldn't grind down that washer on the rear brke bridge to give yourself some extra room.

don't remove the bridge itself though.
dolface is offline   Reply With Quote
Old 02-12-05, 01:58 PM   #4
filtersweep
Senior Member
 
filtersweep's Avatar
 
Join Date: Mar 2004
Bikes:
Posts: 2,615
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If you move your rear wheel as far back as possible in the drops, does it increase clearance a bit?

Frankly, some tires are simply measured incorrectly. Racing oriented tires tend to be undersized so they can brag of being lighter than they really are, while a tire like an Armadillo will run quite large. Also, some tires seem to have a rounder profile or more V-shaped profile, compared to flatter tires (which are sometimes a bit wider). In any case, I wouldn't expect any 35c tire to fit an old road conversion.

Do not remove the rear brake bridge- but you might try filing down the "washer." It doesn't provide any structural support and it will give you a few more millimeters.
filtersweep is offline   Reply With Quote
Old 02-12-05, 02:49 PM   #5
Smorgasbord
Employee
 
Smorgasbord's Avatar
 
Join Date: May 2004
Location: Berkeley, CA, USA, Earth
Bikes: Bridgestone 450, A Camera, 46x18 Fixed Gear, Homebrew Tandem
Posts: 250
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by filtersweep
Do not remove the rear brake bridge- but you might try filing down the "washer." It doesn't provide any structural support and it will give you a few more millimeters.
I actually just did this the other day to my new (to me) Dave Scott Ironman Expert. It worked well.

But actually I wanted to inflate my 27" tire and ended up taking out more of the underside of the bridge. I'll let you know if I die. On the plus side, since I'm running a 700c in front and a 27" in back, I have a sloping top tube.
Smorgasbord is offline   Reply With Quote
Old 02-12-05, 04:45 PM   #6
thechamp
loser
 
Join Date: Jan 2005
Location: portland, or
Bikes: steyr, lejeune, schwinn, sears, crescent, blah blah blah.
Posts: 385
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
tighten all the spokes on the offending wheel 2 full turns. should do the trick...
thechamp is offline   Reply With Quote
Old 02-12-05, 04:54 PM   #7
bikeskatethrash
Senior Member
 
Join Date: Oct 2004
Location: PGH
Bikes:
Posts: 304
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I had the same problem on my track frame riding like size 25 cross tires. I switched once normal road grit started to wear away the paint. If you just leave it, in my experience, it will sand away its own clearence.
bikeskatethrash is offline   Reply With Quote
Old 02-12-05, 05:08 PM   #8
HereNT
無くなった
 
HereNT's Avatar
 
Join Date: Mar 2004
Location: Sci-Fi Wasabi
Bikes: I built the Bianchi track bike back up today.
Posts: 5,073
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I went from 25c Gatorskins to 23c Vittorias and started rubbing on the front fork on my Bianchi. So I took a dremel to it - worked great, no more squeaking sounds. It looked like someone had aready done that before, too.

Looking at your pics, it looks like you don't have the rear wheel all the way back in the dropouts - the further back that they are, the more clearance that you'll have... Of course, less gear ratio options...
HereNT is offline   Reply With Quote
Old 02-12-05, 08:07 PM   #9
RobbieIG
Postmodern Beauty King
Thread Starter
 
Join Date: Oct 2004
Location: Corvallis, OR
Bikes: Centurion Fix, Jamis Nova, Jamis Crosscountry
Posts: 154
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
In that pic, the wheel is about in the center of the drop outs...I checked earlier today and moving it through the dropout really did not have a noticeable affect on the clearance. I think I will try increasing the spoke tension a bit and then just go with it. Ill file the bridge or go for a slightly smaller tire if it gets to be a problem.
RobbieIG 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 02:31 AM.