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 04-20-06, 06:54 PM   #1
pinarelloguy
Newbie
Thread Starter
 
Join Date: Oct 2005
Bikes:
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Rear Derailleur

I am building a second bike with a triple crank set. It is all ultegra. My question is for my rear deraliier do I have to have a long arm or can i use a standard one.
pinarelloguy is offline   Reply With Quote
Old 04-20-06, 07:07 PM   #2
supcom
You need a new bike
 
supcom's Avatar
 
Join Date: Aug 2002
Bikes:
Posts: 5,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You need to determine the required amount of chain wrap. This is the number of teeth difference between the big/big and small/small chainring/cog combinations. For example, if you have a 52-42-30 up front, and an 11-25 rear cassette, then your required wrap is (52+25)-(30+11)=36. Your rear derailler must be able to take up 36 teeth. The derailleur should also be rated for the 25 tooth cog.

Now, you can cheat on this if you use discipline and avoid shifting into the big/big and/or small/small combinations. But it's probably best to get the derailleur that is failsafe.
supcom 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 01:28 AM.