Bicycle Mechanics - Chain length for compact crank change?

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lemondzurich
10-30-09, 03:40 PM
Hey folks,

I replaced my Ultegra 6700 crank with the compact version (50-34). The cassette is the 11-28T. When completely cross chained (which I realized I really wouldn't ever do) the chain is definitely too long. Probably 2 links too long. But when cross chained the other way, taking out two links is probably too much. My thought is that I should just take one out and be done with it. Do folks here concur?

(Still gotta find the reinforced pins... and replace my broken Park Tool chain breaker. In the meantime, I'll just ride it and make sure I don't cross chain.)

Thanks for the input!

operator
10-30-09, 04:18 PM
Assuming 10 speed, forget the pin and buy a 10 speed quick/master link from sram/wipperman. Define, "definitley too long". If the chain is not touching stuff it shouldn't be touching (e.g rd body on the bottom run) on the small/small combo then you should be fine. The chain obviously has some tension if it's not touching anything.
Frosty861
10-30-09, 05:11 PM
Lemond,

Here are a couple of links to answer your question.

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_09G0B/SI-09G0B-003-ENG_v1_m56577569830682232.pdf

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_5X90A_002/SI-5X90A-002-ENG_v1_m56577569830675227.pdf

Note chain length section, middle bottom of 675227.

Enjoy your ride,

Frosty

Frosty861
10-30-09, 05:27 PM
Oops!

Top center.
operator
10-30-09, 05:53 PM
Lemond,

Here are a couple of links to answer your question.

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_09G0B/SI-09G0B-003-ENG_v1_m56577569830682232.pdf

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_5X90A_002/SI-5X90A-002-ENG_v1_m56577569830675227.pdf

Note chain length section, middle bottom of 675227.

Enjoy your ride,

Frosty

Here's a better overview that includes the shimano method:

http://www.parktool.com/repair/readhowto.asp?id=26
lemondzurich
10-30-09, 11:37 PM
Too long = sagging and chain touching itself at the RD. I do like the concept of a master link. I'll look into the sram/wipperman one. Thanks for the links!
DaveSSS
10-31-09, 07:50 AM
You can't just take one link out of a chain. You can remove 1 inch or two links at a time.

If the chains does not hand loose or rub the RD cage in the little ring and smallest cog, the chain is not too long. If the lower pulley on the cage is not applying antension to the chain, it will hang loose or rube and 1 inch needs to be removed.