Fd compatability
#1
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From: NW Peloponnese, Greece
Fd compatability
Crankset FC-5503 (52-42-30) with FD Ultegra 6503.
Tried replacing FD with new Ultegra 6703 because old one had a worn cage, and the new had better leverage.
However, 6703 capacity is minimum difference between top and intermediate 13T mine is 10T.
Front chainwheel difference is 22 or less. I am ok there.
Anyway, installed the new one, but couldn't get it to work properly, and reverted back to the old one.
My existing chainwheel does even meet the FD 105 5703 requirement of 11T difference.
One solution would be to replace middle chain ring of 42 with 39 if I could find one with 130mm bolt circle dia. or the expensive solution of replacing the whole crank and BB.
The new FD is for 3X10, but I have 9 speed cassette, but I don't think this would give me a problem if I met the chainwheel spec.
Is there a solution around this other than the above? Views are appreciated.
Tried replacing FD with new Ultegra 6703 because old one had a worn cage, and the new had better leverage.
However, 6703 capacity is minimum difference between top and intermediate 13T mine is 10T.
Front chainwheel difference is 22 or less. I am ok there.
Anyway, installed the new one, but couldn't get it to work properly, and reverted back to the old one.
My existing chainwheel does even meet the FD 105 5703 requirement of 11T difference.
One solution would be to replace middle chain ring of 42 with 39 if I could find one with 130mm bolt circle dia. or the expensive solution of replacing the whole crank and BB.
The new FD is for 3X10, but I have 9 speed cassette, but I don't think this would give me a problem if I met the chainwheel spec.
Is there a solution around this other than the above? Views are appreciated.
#2
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From: NW,Oregon Coast
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if less t difference and it wont clear the middle chainring. 10 should still be OK*
raise the FD on the seat post a bit. so it clears the middle chainring.
the chain line on the front should line up with # 5 of 9 in the cassette, the Middle.
*I'm running a 50-40-24t triple , friction bar ends and old way Pre STI FD's .. it works fine
a 40-46 difference is another story , there you have to stray from the owner's manual suggestion ..
...
raise the FD on the seat post a bit. so it clears the middle chainring.
the chain line on the front should line up with # 5 of 9 in the cassette, the Middle.
*I'm running a 50-40-24t triple , friction bar ends and old way Pre STI FD's .. it works fine

a 40-46 difference is another story , there you have to stray from the owner's manual suggestion ..
...
Last edited by fietsbob; 05-21-17 at 01:12 PM.
#4
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Joined: Feb 2015
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From: Mission Viejo
Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970
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theblackbullet
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