Bicycle Mechanics - upgraded drivetrain failing

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View Full Version : upgraded drivetrain failing


freefallkev
10-15-09, 05:52 PM
hi all, I recently ran into some trouble with my upgrdaed drive components. I have:

Sugino 46t Chainring
SRAM 11-32t cassette
SRAM 8 spd chain
Shimano Acera RD

The problem is there are HUGE gaps on the chainring where the chain doesn't settle into the "valleys" between teeth. I can line it up approximately 1/8th of the way, but the rest of the teeth don't settle properly. When turning the crank by hand, the chain skips and eventually falls off the ring. I have tried the chain at 54 and 56 links with no success. The previous setup was a 42t chainring and 12-25 cassette, with no problems.

http://i53.photobucket.com/albums/g42/ekoxhalcyon/Mobile%20Uploads/1015091930a.jpg
http://i53.photobucket.com/albums/g42/ekoxhalcyon/Mobile%20Uploads/1015091929a.jpg

Any help would be greatly appreciated... Thanks!


operator
10-15-09, 06:07 PM
Looks like you bought a 1/8 ring instead of a 3/32 "road" ring. I'm assuming the # of chain speeds = # of cogs in teh back because it's hard to see in your pic.

freefallkev
10-15-09, 06:11 PM
Looks like you bought a 1/8 ring instead of a 3/32 "road" ring. I'm assuming the # of chain speeds = # of cogs in teh back because it's hard to see in your pic.

I'm not 100% sure the size of it, the LBS ordered it for me. The mechanics are, as far as I can tell, very knowledgeable, and the meausred the bike first, so I'm hoping that's not it... yes, there are 8 cogs on the cassette.


operator
10-15-09, 06:17 PM
I'm not 100% sure the size of it, the LBS ordered it for me. The mechanics are, as far as I can tell, very knowledgeable, and the meausred the bike first, so I'm hoping that's not it... yes, there are 8 cogs on the cassette.

I can gaurantee you that ring is 1/8. measure the width of the teeth if you want to make sure.

freefallkev
10-15-09, 07:47 PM
I can guarantee you that ring is 1/8. measure the width of the teeth if you want to make sure.

I owe you a :beer:, everything meshes up properly with a stock 52t chainring. f@CK! waited all week for that chainring to come in. everything runs smooth now except for one stupid stuck link in the new chain... oh well, can't win em all...

Thanks a lot for your quick help.

Wanderer
10-15-09, 07:57 PM
Justg flex that chain a little bit, side to side, where the one link isn't moving freely. That will take care of the chain.

freefallkev
10-15-09, 08:40 PM
Just flex that chain a little bit, side to side, where the one link isn't moving freely. That will take care of the chain.

lol thanks, that's actually one of the things I knew how to handle :) was more griping about how new, shiny parts still have bugs.

Everything runs smooth as silk now, going to take that ring back tomorrow and try to get store credit. If that fails, anyone want to buy a 46t chainring cheap?

Thanks for all your help guys/gals, if it weren't for this site my bike would be a broken tangled mess by now :crash:

spinerguy
10-15-09, 09:13 PM
What you got is a track chainring, it appears that you have a 130 BCD crankset.

What you need is a road (whatever # of teeth) in 130 BCD. Even if they meshed properly tracks teeth are different from road's (ramped & pinned) which prevent them from smooth shifting.

operator
10-15-09, 10:24 PM
What you got is a track chainring, it appears that you have a 130 BCD crankset.

What you need is a road (whatever # of teeth) in 130 BCD. Even if they meshed properly tracks teeth are different from road's (ramped & pinned) which prevent them from smooth shifting.

He's running a single chainring up front so it won't matter. You can run a road chain on a 3/32 "single-speed"/track chainring just fine. Especially since he's not running two chainrings.