Bicycle TutorBicycle Tutor

Show off your bike!

Related video tutorials:
Changing 53/39 chainrings to 50/34
#1
I'm looking to change a Shimano 105 53/39 crank/chainring to a 105 (or higher spec) 50/34 chainring. Can anyone please tell me what is involved with this? Do I just need to change the chainrings, or am I going to end up needing to change pretty much the whole drive train? Thanks.
Reply
#2
A 50T would fit where the 53T is but the 34T won't fit instead of the 39T.
It's to do with the "PCD" (pitch circle diameter) of the chainset.
ie the mounting holes for the rings are on a different radius for the small ring.
You will need change the right crank or change the chainset as a whole.
The chances are your PCD is 130mm whereas you need 110mm for the 50/34 chainrings.

See:-
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_1M30A/SI-1M30A-003-ENG_v1_m56577569830702207.pdf

The other thing you will have to check is if the front dérailleur is also compatible with the smaller ring?
Probably is but some aren't.
[font=Trebuchet MS]Ride hard or ride home alone![/font]
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Cheap, welded chainrings? Far Away 16 8,426 05-26-2014, 07:36 AM
Last Post: Far Away
  Are my chainrings worn? d3v 4 4,297 06-09-2013, 12:48 PM
Last Post: bobtravers
  Chain skip from chainrings? larsonian 6 7,185 04-05-2013, 02:44 AM
Last Post: larsonian
  CODA 300 Crankset Chainrings??? rb64 14 11,270 08-30-2012, 10:36 PM
Last Post: xerxes
  Upgrade: BB, Cassette, chain, chainrings & crankset Fox 1 5,111 02-28-2012, 05:25 PM
Last Post: DaveM
  Chain jammed between chainrings TheMarlow 3 7,158 01-13-2011, 09:48 AM
Last Post: trevgbb
  Chainrings needed for half-step plus granny gearing junoak04 5 6,953 08-29-2010, 05:13 AM
Last Post: junoak04
  Replace worn chainrings questions Copro 4 10,867 04-26-2010, 07:43 PM
Last Post: GeorgeET
  How to tell if the Chainrings are worn. oceantin 1 7,737 10-21-2008, 05:24 PM
Last Post: Alex Ramon
  Chainrings - 44 to 42 artcat2 2 5,545 10-19-2008, 10:39 PM
Last Post: artcat2

Forum Jump:



ISSN 1918-3445 © Copyright 2007-2010 Bicycle Tutor / Privacy Policy / Created by Alex Ramon

feed