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 11-19-07, 09:19 AM   #1
MotoMan
Old Crank
Thread Starter
 
Join Date: May 2006
Location: Vermont
Bikes: Bianchi Eros; Motobecane Grand Touring; Nashbar Fra-may;Motobecane Grand Jubilee;Bianchi Advantage; Puegout UO-8;Specialized Mtn Bike.
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Cranks/BB size XD Crank 120mm spacing

I have a Motobecane Grand Touring from the 70's with 120mm rear spacing for the days of 5 speed freewheels. I am thinking of putting a Sugino XD2 110/70 triple crank to help my aging knees. What size BB? Yes, there is the Swiss threading to deal with. I see on the Yellow Jersey site of having 108/113 size straight axles. Also,I own a Phil Wood 108 BB with the Swiss retaining rings. What size to use on the 10 speed era bike? The chainrings will be something like 48-6/36/26-4. I will probably use a 5 speed freewheel 13-28 or 13-32 range. Will my Phil work with this set up. Any suggestion for front derailleur? Thank you for your input.
MotoMan is offline   Reply With Quote
Old 11-19-07, 01:20 PM   #2
Iowegian
Senior Member
 
Iowegian's Avatar
 
Join Date: Dec 2005
Location: Boulder, Colo
Bikes:
Posts: 1,836
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
I'd stick with the Phil BB. If the 108 doesn't work with that crank check with Phil to see if they can replace the spindle for you. Their parts are built to last and they do service what they sell.

I'm not certain what the normal chainline for 120mm spacing is but you can probably find the answer to that on Sheldon Brown's site. If your bike originally came with 2 rings up front, you could have problems with clearance next to the chainstay unless you move the crank outboard a bit so watch for that.

Any FD built for 'compact' cranks should work as long as it mounts to your tubing size. I'd get one that has a flexible mount instead of a cast mount in case your tubing diameter is a bit off of current standard.
Iowegian is offline   Reply With Quote
Old 11-19-07, 08:36 PM   #3
JunkYardBike
Since 1938...
 
JunkYardBike's Avatar
 
Join Date: Aug 2006
Location: Northwestern NJ
Bikes:
Posts: 6,208
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Here's Sheldon Brown's write-up on chainline: http://sheldonbrown.com/gloss_ch.html#chainline

The unknown variable is the offset of the cranks once they've been mounted on your BB. Trial and error is your best bet. I'm using a Sugino XD on a 110mm spindle with an 8 speed cassette on the rear, and the crank is still too far outboard for me, since I use the outer two rings more often. I could probably move in 1 or 2 millimeters, but I can't afford Phil.

As for FD's, I'm using a Suntour Cyclone MKII on the stock 46/36/26 setup, and it works admirably well. However, I've had to mount it higher than normal to avoid interference with the RD cable, a problem you'll find if you have above the chainstay cable routing (because the FD will be mounted lower). Someone suggested I try this Suntour XC Expert Microdrive FD available on ebay. I bought one, but haven't yet mounted it. (Oh, and mine came with the clamp bolt, despite the item description).

Last edited by JunkYardBike; 11-19-07 at 08:41 PM.
JunkYardBike 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 05:06 AM.