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chain alignment ?(10 posts)

chain alignment ?marcmarc
Oct 3, 2002 6:54 AM
I switched an old crank(105) out with a raceface next lp crank. the front derailler is way off to the inside. the existing bottom bracket is a 110mm. should i try to use this 110mm bracket or just switch to a 107mm? And will my chain alignment be off if i don't switch to a 107mm? Frame is a lemond poprad.

thanks for any thoughts,
marc
QuestionsBipedZed
Oct 3, 2002 7:23 AM
Was the 105 crank a triple? Are you running a two or three rings on the Race Face? What kind of front derailleur are you using - the stock triple 105?

If your 105 was a triple and you have a triple front der than you should be able to use the same BB spindle. Just readjust the limit screws on the front der. If you are trying to use the Race Face with the 2 outer rings and a road front der (not triple) then you will need a 102mm BB spindle for optimal front shifting.
answersmarcmarc
Oct 3, 2002 9:37 AM
Here's the rest that i left out & a correction:
The old crank was a Dimension road crank setup w/ 2 raceface chain rings.
The frt derailleur is a LX.
Bottom bracket is 68x110 (UN-71 ?)

Using existing racefaces rings (48&36) on the new Next lp crank.

From what you stated prior I may need a shorter bb then??

thanks,
marc
Try adjusting front der. limits firstBipedZed
Oct 3, 2002 11:30 AM
Since you are using a LX MTB derailleur try adjusting the limit screws to allow adequate range for the RaceFace cranks. If you can't get the outer cage over enough to consistently shift into the large ring then a 68x107mm UN-72 should do the trick.
Race Face Cranktriangleforge
Oct 3, 2002 1:20 PM
FWIW, a buddy of mine is running a single ring on a Race Face Next LP crank on a Surly CrossCheck (mounted on the "middle" ring position, with a guard on the outside). He's buying a 103 bb from me because he's not happy with the chainline. I looked at it the other day, and he's definitely got a good 5mm or more that he can & should go inboard.

Cheers!
re:answersTWD
Oct 3, 2002 2:53 PM
I'm running Next LPs with a 68x107 UN72 BB, 34/46 race face rings, and and LX front der. This chainline is not real great. I haven't measured it, but I'd say a 102mm BB would put it about right for a two ring setup.

My setup still shifts fine, it's just when I'm in the 34T ring and the largest cog in back the chain is crossed over pretty far.

I've been thinking of putting the granny ring back on after the last cross race of the season since I'll be using the bike all winter for mountbike type rides with several thousand feet of steep muddy climbing.

Not sure if it will work since I've read that you can't run triple setup with STI levers and a mountain front der.
DA 103mm BBBipedZed
Oct 3, 2002 3:40 PM
http://www.excelsports.com/item.asp?major=1&minor=6&description=Dura%2DAce+Bottom+Bracket+8+Speed&vendorCode=SHIM

This is what I use with RaceFace cranks 48/36.

As an aside this season I switched to 9spd (46/39) DA cranks/DA BB and the shifting is excellent. The 48/36 RaceFace with 103mm BB/Ultegra f der was good but would occasionally drop the chain going to the 36 in hard race situations.
re: chain alignment ?BAM
Oct 3, 2002 5:13 PM
I`m using a Real Design Crankcase B/B in 107 on mine and am also only running two rings. I had to respace the B/B (uses spacers) to the left by a mm to correct the chainline.
It's done!marcmarc
Oct 4, 2002 8:59 AM
Thanks for all helps & thoughts above!

I ended up using 48/36 rings & NextLP with a 105mm titanium TNT brand bb. It's very light, 155gm, hoping it holds up, have never heard of this brand bb. (A buddy offered it since he could not use on his ss project.) Lineup and shifting is looking pretty good, but needs more fine tuning this weekend.

marc
& picturemarcmarc
Oct 5, 2002 6:43 PM
sorry about pic quality, very old digital camera.