Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Rear derailleur questions

Notices
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.

Rear derailleur questions

Old 12-02-12, 11:24 AM
  #1  
jpsawyer
Senior Member
Thread Starter
 
jpsawyer's Avatar
 
Join Date: May 2011
Location: Providence, RI
Posts: 599

Bikes: Civilian Le Roi Le Veut, Kazane Track, Ciocc Designer '84, Serotta Colorado AL 25th anniversary, '85 Guerciotti Pista, '84 Trek 660, Volume Credence

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Rear derailleur questions

I am currently building up a 1x10 cross bike and had some questions about which kind of rear derailleur I should order. Most questions about the chain wrap capacity and stuff. I plan on running a 42T chainring in the front and either a 11-30T or 11-32T cassette in the back. Would a rear derailleur with a chain wrap capacity of 35T do the trick or do I need one wit more capacity? Thanks!
jpsawyer is offline  
Old 12-02-12, 11:55 AM
  #2  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 37,685

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 134 Post(s)
Tagged: 1 Thread(s)
Quoted: 5257 Post(s)
Liked 1,564 Times in 896 Posts
Chain wrap involves the sum of the differences of the largest and smallest sprockets front and back, ie. 53-39 and 11-26 = 14+15 or 29t total.

Since you're building a 1x10, you only look at the cassettes range or 22t. That's well within the range of short cage RDs, so you can use anything you want, including one with 25t capacity.

I prefer using the shortest cage possible (or what I already have) for a variety of minor reasons, so if you're buying new, and have no intention of ever going double up front, consider a shorter cage RD, provided it's compatible with a 32t rear sprocket.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
alij2018
General Cycling Discussion
12
06-20-19 03:15 PM
enderconka
General Cycling Discussion
13
02-11-18 12:02 PM
TimothyH
Road Cycling
4
07-12-16 04:00 PM
Duane Behrens
Bicycle Mechanics
7
06-02-14 10:09 PM
sprocket47
Bicycle Mechanics
7
03-25-10 08:29 AM

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.