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 02-23-09, 11:18 PM   #1
tydirium69
Newbie
Thread Starter
 
Join Date: Feb 2009
Location: Reno, NV
Bikes: 1998 Trek Y3 & 2001? Gary Fisher F3
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
distance from MTB chainring to frame.

Hello, I am new to this forum. I currenty have a 98 Trek Y3, and a 2001 (I think) Gary Fisher Joshua F3. My dilemna is I am building an aluminum rearend for the Y3. I purchased a Phil Wood titanium BB for this new rearend. My question is what is supposed to be the distance between the smallest of three chainrings to the frame?
tydirium69 is offline   Reply With Quote
Old 02-24-09, 12:36 AM   #2
bikinfool
I have senior moments...
 
bikinfool's Avatar
 
Join Date: Oct 2008
Location: Woodside, CA
Bikes: Many
Posts: 2,152
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Chainline for a three ring crank like yours is the measurement to the middle chainring from the center of the seat tube; typical chainlines on mountain bikes are 47.5 or 50mm.
bikinfool is offline   Reply With Quote
Old 02-24-09, 12:50 AM   #3
Panthers007
Great State of Varmint
 
Panthers007's Avatar
 
Join Date: Sep 2008
Location: Dante's Third Ring
Bikes:
Posts: 7,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My Trek 7.5 hybrid measures 50mm on the dot with an Ultegra triple crankset.
Panthers007 is offline   Reply With Quote
Old 02-25-09, 12:14 AM   #4
tydirium69
Newbie
Thread Starter
 
Join Date: Feb 2009
Location: Reno, NV
Bikes: 1998 Trek Y3 & 2001? Gary Fisher F3
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What is a good way to measure chainline to seat tube?

I have a set of calipers and is difficult to measure correctly, do you guys have a trick up your sleeves for that? Any way, from what I could measure, I got little over 53mm. So will try to adjust the BB spindle tommorrow. But if I shoot for perfect, aim for 48.5mm? Or is this more something when the rear deraileur and hub with cassette is all together to determine chainline? Trek was kind to leave an indented dot that I assume is center to seat tube.
tydirium69 is offline   Reply With Quote
Old 02-25-09, 02:07 AM   #5
bikinfool
I have senior moments...
 
bikinfool's Avatar
 
Join Date: Oct 2008
Location: Woodside, CA
Bikes: Many
Posts: 2,152
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by tydirium69 View Post
I have a set of calipers and is difficult to measure correctly, do you guys have a trick up your sleeves for that? Any way, from what I could measure, I got little over 53mm. So will try to adjust the BB spindle tommorrow. But if I shoot for perfect, aim for 48.5mm? Or is this more something when the rear deraileur and hub with cassette is all together to determine chainline? Trek was kind to leave an indented dot that I assume is center to seat tube.
A ruler can work well. Somewhat depends on the seat tube thickness as well as your rear gear setup; 47.5 was common for the thinner seat tubes, moved out to 50 with the fatter ones for the most part. Try this http://sheldonbrown.com/chainline.html
bikinfool 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 03:09 PM.