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

Is it possible to run a PG-1050 11-32T or 12-32T with a Shimano FC-6703 triple crank?

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.

Is it possible to run a PG-1050 11-32T or 12-32T with a Shimano FC-6703 triple crank?

Old 09-06-11, 11:52 AM
  #1  
Senior Member
Thread Starter
 
volosong's Avatar
 
Join Date: Apr 2011
Location: North Idaho
Posts: 2,809

Bikes: n + 1

Liked 27 Times in 15 Posts
Is it possible to run a PG-1050 11-32T or 12-32T with a Shimano FC-6703 triple crank?

Looking at those low to mid twenties percent gradient ramps on a hill I want to climb on my Ultegra spec road bike. Bike currently has a FC-6703 triple crankset (52/39/30), a RD-6700 GS (long cage) rear derailleur, and 11-28T CS-6700 cluster.

Can I use a SRAM PG-1050 11-32T or 12-32T cluster with the triple crank and long cage derailleur?

Shimano specs say not, but with the long cage, maybe somebody here has been able to get it to work. I would think so because the short cage derailleur also says you can run an 11-28T; surely the long cage will allow more.
volosong is offline  
Old 09-06-11, 01:53 PM
  #2  
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Likes: 0
Liked 7 Times in 6 Posts
Long cage road derailleurs have the same large cog limitation as a short cage derailleur. The difference is how much chain can be wrapped on the derailleur to avoid a slack chain. The smaller sized chainring on a triple creates slack in the chain if the rear derailleur is not long cage. Mountain style RD's are designed to accept larger cogs, whether short, medium, or long cage.

Having said that, some people have been able to make a road derailleur work with a 32 tooth cog. This usually requires replacing the "B" screw with a longer one. The length of the derailleur hanger is also a factor on the maximum cog size that will work. Most Shimano rear derailleurs can be made to work with a 30 tooth cog.

I'm amazed at how often it's necessary to explain the difference between wrap capacity limit and cog size limit.
Al1943 is offline  
Old 09-06-11, 03:00 PM
  #3  
Senior Member
 
Drew Eckhardt's Avatar
 
Join Date: Apr 2010
Location: Mountain View, CA USA and Golden, CO USA
Posts: 6,341

Bikes: 97 Litespeed, 50-39-30x13-26 10 cogs, Campagnolo Ultrashift, retroreflective rims on SON28/PowerTap hubs

Liked 326 Times in 226 Posts
Originally Posted by volosong
Looking at those low to mid twenties percent gradient ramps on a hill I want to climb on my Ultegra spec road bike.
Change the granny ring to something smaller (use a chain catcher and avoid the small cogs in the small ring if you exceed the rear derailleur wrap capacity) with 26x28 as low as 30x32 and 24x28 like 30x35.

It'll cost less and not introduce additional gaps in your gearing for flat ground.

Last edited by Drew Eckhardt; 09-06-11 at 06:26 PM.
Drew Eckhardt is offline  
Old 09-06-11, 03:30 PM
  #4  
Senior Member
Thread Starter
 
volosong's Avatar
 
Join Date: Apr 2011
Location: North Idaho
Posts: 2,809

Bikes: n + 1

Liked 27 Times in 15 Posts
Thanks, guys, for the info. Appreciate it.

I'll look around for a compatible, and smaller, granny gear. Sounds like a simple "fix". Just need to check my chain length. Not sure if I'll need a chain catcher if the stop screw is properly adjusted. Also, it's not a braze-on FD, so would have to see if a chain catcher can even be mounted.
volosong is offline  
Old 09-06-11, 05:10 PM
  #5  
Constant tinkerer
 
FastJake's Avatar
 
Join Date: May 2010
Location: Wisconsin
Posts: 7,954
Liked 92 Times in 75 Posts
Originally Posted by volosong
Not sure if I'll need a chain catcher if the stop screw is properly adjusted.
FDs can have problems dumping the chain off if your granny ring is too small. Having said that, try it and see how it works before buying/installing a chain catcher.

I agree with the suggestion to replace the granny ring. You get more gear with (probably) less hassle.
FastJake is offline  
Old 09-06-11, 06:25 PM
  #6  
Senior Member
 
Drew Eckhardt's Avatar
 
Join Date: Apr 2010
Location: Mountain View, CA USA and Golden, CO USA
Posts: 6,341

Bikes: 97 Litespeed, 50-39-30x13-26 10 cogs, Campagnolo Ultrashift, retroreflective rims on SON28/PowerTap hubs

Liked 326 Times in 226 Posts
Originally Posted by volosong
Thanks, guys, for the info. Appreciate it.

I'll look around for a compatible, and smaller, granny gear. Sounds like a simple "fix". Just need to check my chain length. Not sure if I'll need a chain catcher if the stop screw is properly adjusted. Also, it's not a braze-on FD, so would have to see if a chain catcher can even be mounted.
The Third Eye, Deda Dog Fang, K-Edge clamp on, and N-Gear Jump Stop are all clamp-on. IIRC the Third Eye is the only one which is a universal fit with the others having different clamp sizes to match different seat tube diameters.

Last edited by Drew Eckhardt; 09-13-11 at 04:31 PM.
Drew Eckhardt is offline  
Old 09-06-11, 07:34 PM
  #7  
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,903
Liked 786 Times in 412 Posts
Originally Posted by FastJake
FDs can have problems dumping the chain off if your granny ring is too small. Having said that, try it and see how it works before buying/installing a chain catcher.

I agree with the suggestion to replace the granny ring. You get more gear with (probably) less hassle.
Ultegra crank with 24/42/52, SRAM 11-34 cassette, XTR rear derailleur:
https://home.comcast.net/~jeff_wills/...-grr%20008.htm
https://home.comcast.net/~jeff_wills/...-grr%20006.htm
They all work together fine, and I've never had a problem dropping the chain off the granny ring. Low gear is enough to climb an 18% grade with a full touring load.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline  
Old 09-06-11, 07:47 PM
  #8  
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Likes: 0
Liked 1,099 Times in 745 Posts
Originally Posted by Jeff Wills
Ultegra crank with 24/42/52, SRAM 11-34 cassette, XTR rear derailleur:
That's the secret of the 11x34 cassette working. As Al1943 noted some riders have reported success with a road rd clearing a 32T big cog but it's not sure thing and most report failure with a 34T.

I do agree with the change to the granny ring being the least expensive option and further agree with the chain watcher recommendation. I've done both on most of my bikes.
HillRider is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
enderconka
General Cycling Discussion
13
02-11-18 12:02 PM
squatchy
Bicycle Mechanics
4
07-13-14 07:37 PM
Duane Behrens
Bicycle Mechanics
7
06-02-14 10:09 PM
Ansir
Road Cycling
13
01-31-11 05:13 PM
thenotoriousffj
Road Cycling
4
07-12-10 02:30 PM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Your Privacy Choices -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.