Sincitycycler
10-22-05, 02:17 PM
Do you need a different chain or any special adjustments anywhere? :)
Bicycle Mechanics - Any adjustments needed if you convert a 53/39 to a 50/36
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meb
10-22-05, 02:37 PM
Do you need a different chain or any special adjustments anywhere? :)
Not likely to be essential, but a couple likely for optimization:
Might want to take out a link or two to keep chain tension correct.
Might want to lower the fder in accordance with the drop in the ring heights to have the fder aligned with the rings for optimal shifting.
Not likely to be essential, but a couple likely for optimization:
Might want to take out a link or two to keep chain tension correct.
Might want to lower the fder in accordance with the drop in the ring heights to have the fder aligned with the rings for optimal shifting.
Retro Grouch
10-22-05, 04:16 PM
Do you need a different chain or any special adjustments anywhere? :)
When I installed mine I lowered the front derailleur a bit, resized the chain which resulted in removing 1 inch of chain, and reprogrammed my flight Deck computer. Actually I removed, regreased and reinstalled the bottom bracket too. The whole process took a little under an hour and the only thing that I had to buy was the crankset.
When I installed mine I lowered the front derailleur a bit, resized the chain which resulted in removing 1 inch of chain, and reprogrammed my flight Deck computer. Actually I removed, regreased and reinstalled the bottom bracket too. The whole process took a little under an hour and the only thing that I had to buy was the crankset.
cs1
10-22-05, 05:46 PM
Do you need a different chain or any special adjustments anywhere? :)
If you are using a Shimano probably not. Shimano double front derailleurs can handle the 14 teeth jump. There are a lot of forumites that complain about the 50/34 though.
Tim
If you are using a Shimano probably not. Shimano double front derailleurs can handle the 14 teeth jump. There are a lot of forumites that complain about the 50/34 though.
Tim
DannoXYZ
10-22-05, 07:07 PM
But you still need to lower the derailleur on the seat-tube so that the outer-cage is 1-1.5mm above the big-ring. Or else it's going to take a LONG cable pull for the same action as before...
sydney
10-22-05, 07:11 PM
Pull will be excactly the same.
John E
10-22-05, 07:23 PM
I changed the Bianchi from 52-42 to 50-42 without lowering the Campag. Record front derailleur, although I really should drop it a bit ...
DannoXYZ
10-22-05, 09:45 PM
Pull will be excactly the same.Yes, the cable pull on the derailleur will the same to make the derailleur move the same amount. However with the derailleur further away from the chain, you have to move it more to bend the chain to the same angle.
Here's a good procedure for the front-derailleur from Park Tool Co. (http://www.parktool.com/repair/readhowto.asp?id=75). The very first step is to make sure the derailleur is just a penny's thickness from the chainring teeth.
http://www.parktool.com/images_inc/repair_help/ft_der_2.jpg
Assuming the front-derailleur is adjusted properly to be this close with the 53t chainring, going to a 50t will increase the gap to about 6mm, much, much too large for quick and easy shifts.
Here's a good procedure for the front-derailleur from Park Tool Co. (http://www.parktool.com/repair/readhowto.asp?id=75). The very first step is to make sure the derailleur is just a penny's thickness from the chainring teeth.
http://www.parktool.com/images_inc/repair_help/ft_der_2.jpg
Assuming the front-derailleur is adjusted properly to be this close with the 53t chainring, going to a 50t will increase the gap to about 6mm, much, much too large for quick and easy shifts.
HillRider
10-23-05, 08:48 AM
One precaution when setting the front derailleur height on Shimano cranks. Shimano's large chainrings have several short "release" teeth to improve shifting. Be sure you don't set the FD height based on one of these teeth or the normal height teeth may hit the cage plate.
Don't ask how I know this. :)
Don't ask how I know this. :)