going from 50/34 to 53/39 crank
10-20-09 | 06:02 PM
#3
Full Member
Joined: Jan 2009
Posts: 493
Likes: 19
From: Tampa Fl
Bikes: Cannondale Six13 Pro, Cannondale Synapse, Felt IA10, BMC TimeMachine
I just did this in reverse swapping an Ultegra 53/39 for a 50/34. Adjusted the FD and took a couple of links out of the chain.
More than likely you'll have to add a couple.
More than likely you'll have to add a couple.
10-20-09 | 06:07 PM
#4
Low car diet
Joined: Aug 2007
Posts: 2,407
Likes: 4
From: Corvallis, OR, USA
Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.
Possibly need to lengthen the chain. If the chain was previously sized to be as short as possible with the 50T ring, then it will be too short for 53T. See here: https://sheldonbrown.com/derailer-adjustment.html#chain
Before adding links, think about this:
1) Does the chain require a special connecting pin (Shimano) or quick-link? The design of newer chains allows the chains to be stronger, but removing and re-connecting the same pin can damage the outer plate, creating a significant weak spot.
2) How old is the chain? If it's stretched enough, it may be best to just replace the whole chain.
Before adding links, think about this:
1) Does the chain require a special connecting pin (Shimano) or quick-link? The design of newer chains allows the chains to be stronger, but removing and re-connecting the same pin can damage the outer plate, creating a significant weak spot.
2) How old is the chain? If it's stretched enough, it may be best to just replace the whole chain.
10-20-09 | 06:09 PM
#5
Low car diet
Joined: Aug 2007
Posts: 2,407
Likes: 4
From: Corvallis, OR, USA
Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.
Also, going to a new crank may require a new bottom bracket if the crank/bottom bracket interface is different (square-taper vs. ISIS vs. External, etc.) or a different spindle length is required.
10-20-09 | 07:31 PM
#6
Determined Survivor
Joined: Dec 2008
Posts: 169
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From: Ontario, Canada
Bikes: Cervelo R3, Specialized Transition, Kona Paddy Wagon, Giant TCX. Lots of bikes in the Garage.
Don't bother changing the botom bracket or even the crank arms.
Chances are your 50/34 is a 110 not a 130mm.
I made the same move as you.
I just ordered a 52/38 set of chain rings.
The theory is that the change only cost about $150 and if I am planning on a big hard hilly Century the chain rings can go back to 50/34 in a couple of minutes.
My problem with the 50/34 was that I didn't like the big gear spread. If you are just looking for speed it is not rally going to gain you very much. Why not install a 23-11 or a 25-11 cog? or If you really believe that you have power to burn try a 21-11 cog.
Much easier to change sprockets than chain rings.
Chances are your 50/34 is a 110 not a 130mm.
I made the same move as you.
I just ordered a 52/38 set of chain rings.
The theory is that the change only cost about $150 and if I am planning on a big hard hilly Century the chain rings can go back to 50/34 in a couple of minutes.
My problem with the 50/34 was that I didn't like the big gear spread. If you are just looking for speed it is not rally going to gain you very much. Why not install a 23-11 or a 25-11 cog? or If you really believe that you have power to burn try a 21-11 cog.
Much easier to change sprockets than chain rings.
10-21-09 | 12:25 PM
#9
Thread Starter
Junior Member
Joined: May 2009
Posts: 21
Likes: 0
From: Hampton, VA
Thanks for all of the input. I'm in the process of acquiring parts so I can build up a second bike. I would put the 53/39 on my main bike and put the compact on a second bike. Some good CL deals on cranks now. I'll get some advice from the LBS as far as chains go too.
