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 03-18-06, 09:25 PM   #1
Downshift
Senior Member
Thread Starter
 
Join Date: Aug 2004
Location: N. Fla
Bikes: 86 Schwinn Peloton (under construction)
Posts: 261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
126 rear spacing and cassettes

What is the largest cassette you can run on a 126mm rear without cold setting the frame? 6,7,8,9?
Thanks
Downshift is offline   Reply With Quote
Old 03-18-06, 10:04 PM   #2
cascade168
Klaatu barada nikto
 
cascade168's Avatar
 
Join Date: Sep 2004
Location: Southern NH
Bikes:
Posts: 1,453
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Downshift
What is the largest cassette you can run on a 126mm rear without cold setting the frame? 6,7,8,9?
Thanks
You can get 8. If you check this page:

http://sheldonbrown.com/k7.html

and scroll down to the section titled "8 Of 9 On 7", it is explained there. If you look around, you can still get NOS 105 hubsets that have a 126mm rear hub. These are pretty nice.
cascade168 is offline   Reply With Quote
Old 03-18-06, 10:24 PM   #3
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Bikes: Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
Posts: 18,060
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 228 Post(s)
Quote:
Originally Posted by cascade168
You can get 8. If you check this page:

http://sheldonbrown.com/k7.html

and scroll down to the section titled "8 Of 9 On 7", it is explained there. If you look around, you can still get NOS 105 hubsets that have a 126mm rear hub. These are pretty nice.
You can also run a 130 mm hub in a bike with a 126 spacing without cold setting the frame. Frames have enough flex in the rear triangle to accommodate an extra 4mm. Going to a 135 would be too much but 130 is okay. I've done it on a couple of bikes without any problems other than being tight to install or remove the wheel.
__________________
Stuart Black
New! Pokin' around the Poconos A cold ride around Lake Erie
New! Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
An Good Ol' Fashion Appalachian Butt Whoopin'.
cyccommute is offline   Reply With Quote
Old 03-18-06, 10:41 PM   #4
cascade168
Klaatu barada nikto
 
cascade168's Avatar
 
Join Date: Sep 2004
Location: Southern NH
Bikes:
Posts: 1,453
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cyccommute
You can also run a 130 mm hub in a bike with a 126 spacing without cold setting the frame. Frames have enough flex in the rear triangle to accommodate an extra 4mm. Going to a 135 would be too much but 130 is okay. I've done it on a couple of bikes without any problems other than being tight to install or remove the wheel.
Oh, I agree with that - absolutely. But, personally, I hate installing a rear wheel while trying to spread the chainstays at the same time. That's a royal PITA. I like dropouts to be about 1mm wider than the hub O.L.D. That is sooooo much easier.
cascade168 is offline   Reply With Quote
Old 03-18-06, 10:51 PM   #5
Downshift
Senior Member
Thread Starter
 
Join Date: Aug 2004
Location: N. Fla
Bikes: 86 Schwinn Peloton (under construction)
Posts: 261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sweet. I looked all over for that article and couldn't find it.
Downshift is offline   Reply With Quote
Old 03-18-06, 11:06 PM   #6
cascade168
Klaatu barada nikto
 
cascade168's Avatar
 
Join Date: Sep 2004
Location: Southern NH
Bikes:
Posts: 1,453
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Downshift
Sweet. I looked all over for that article and couldn't find it.
Look on the page I linked to and go almost all the way to the bottom. It's just a few sections up from the bottom, just below this section:

"Upgrading From 6-/7-speed (126 mm) to 8-/9-speed (130 mm)"

BTW, that whole page is well worth reading. There is a wealth of useful information there for anyone wanting to do speed upgrades on Shimano hubs.
cascade168 is offline   Reply With Quote
Old 03-18-06, 11:14 PM   #7
TallRider
me have long head tube
 
TallRider's Avatar
 
Join Date: Oct 2005
Location: Chapel Hill, NC
Bikes:
Posts: 4,106
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
7-speed freehubs are designed with 126mm spacing. 8/9/10 speed freehubs (which, from Shimano, are interchangable; an 8/9/10 speed cassette fits on the same sized freehub) are designed with 130mm spacing.

Specifically, steel or titanium frames are flexible enough to spread the frame that extra 4mm to run a 130mm rear hub in a frame designed for 126mm.

But alternately, you could take a 130mm-spaced hub, remove a washer or two on the non-drive side of the axle, and get 126mm spacing with a slightly re-dished wheel. Not an ideal solution (results in a weaker wheel) but it works okay, actually. Provided you're quite good with wheelbuilding. If you do this with a Shimano hub, it's not that much different than a Campy hub with unmodified spacing (Campy hubs have more dish than Shimano, because of the flange placement).
TallRider is offline   Reply With Quote
Old 03-19-06, 07:16 AM   #8
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Bikes: Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Catrike 559, Merin Bear Valley (beater bike).
Posts: 26,740
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 142 Post(s)
Quote:
Originally Posted by timcupery
But alternately, you could take a 130mm-spaced hub, remove a washer or two on the non-drive side of the axle, and get 126mm spacing with a slightly re-dished wheel. Not an ideal solution (results in a weaker wheel) but it works okay, actually. Provided you're quite good with wheelbuilding. If you do this with a Shimano hub, it's not that much different than a Campy hub with unmodified spacing (Campy hubs have more dish than Shimano, because of the flange placement).
Not an idea that I'd copy. If you scan the posts for any period of time you will read of lots of folks who have spoke breakage problems with rear wheels. The issue is that on 8-speed hubs and above, it takes a careful wheelbuild to get adequate tension on the non-drive side spokes. If you respacer and redish an 8-speed hub to fit 126mm dropouts, you are going to worsen that problem. Sometimes there are things that I'd do on a personal bike that I wouldn't do on a customer's bike because I have to guarantee my work. I'm not going to try this one on either.
Retro Grouch 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 PM.