Bicycle Mechanics - Chain, limiter or what

I took my Trek 5200 in for a new 8speed Sram cassette and Sram chain. When I got it home, there was a large fracture in the 105 crank so I took it back in and they put on an Ultegra 10 speed crank.

Then the thing wouldn't shift well even after fiddling with the limit screw adjustment. So I took the mess back and they "quickly adjusted it"...

Got it home and after shifting to the smaller chain ring? WTF? same thing all over again :mad: OK so now tomorrow's commute is wrecked (not to mention wasting the weekend cleaning, and trying to figure out the problem. That was no cheap repair why didn't the shop make sure the bike worked on all gears?

Nice crank but it doesn't. Help! Is there a special chain for the Ultegra 6600 crank????

EDITED: Limiter screw for smaller chain ring aligned for only the 3 biggest cogs on the cassette...extra unscrewing does nothing to align chain. Help!

When the chain is on the small ring and big cog, what is the chain rubbing against? The big ring?

So you have an 8sp cassette and an 8sp chain and a 10sp crank? Isn't the spacing and chain width different for 8 and 10sp? If that's what's going on, the mechanics should have known better. However, you should be able to fix it with chainring bolt spacers to move small ring in a tad. I think the 10sp rings are thinner, too. But it shouldn't be a problem.

How did the 105 crank get damaged?

The 105 had a hair line fracture where the end of the crank joins the chain rings I guess from climbing hills over the past 2 yrs.

The 6600 crank was the only one they had. The thing is unridable. I don't have spacers or tools to remove the crank. Guess I'll have to take it back.

>When the chain is on the small ring and big cog, what is the chain rubbing against? The big ring?
Yeah it was sort of stuck between the 2 chain rings.

Limit-screws does nothing for shifting precision and alignment. They just ensure that the derailleur doesn't move too far inwards or outwards and dump your chain. To adjust the alignment of the derailleur over each chainring, that requires adjusting the cable tension... If it doesn't go down into the smaller rings easily, loosen the cable. If it doesn't go up into the big-ring easily, tighten the cable. If it goes up easily but down slowly or eventually with a time-delay , you've got cable-friction...

Did you get a new BB with the cranks set? Even if the spline is the same, different cranks may need a different BB spindle length. This would certainly affect chain line and shifting.

The Ultegra 6600 requires it's own BB. Although the the 8-speed shifters and cassette were compatible, the mechanic and I could get smooth indexing on all gears. Sure it worked on the mechanic's stand but didn't cut it out on the road.

So I ended up upgrading to 10 speed Ultegra for everything. They gave me a great deal and my money back on the 8 speed cassette and chain (less than 10 mi on them).

Ugg...$$$...my head is still spinning. While waiting for them to put the shifters and derailers, I wandered over to see what that same money would buy in a new bike... not much.