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DuraAce 8-spd Tuning and Chainline(9 posts)

DuraAce 8-spd Tuning and Chainlinescopestuff2
Oct 6, 2003 8:14 AM
I recently purchased a used Serotta with an 8-spd DuraAce drivetrain. 53/39 and 13/26.

I cannot seem to get the chainline to cooperate.

I cannot get it to not drag on the front deraillure when crossed small/small or large chain ring and the largest two cogs- no matter how much I tweak the front deraillure settings.

Trying to quiet the small chainring and small cog I adjust the front deraillure. When adjusted so the chain is not dragging on the front deraillure, the chainline is pulling the chain against the large chainring. So, even with the front deraillure out of the question, the chain is dragging on the large chainRing when crossed small/small.

Is this just a characteristic of the older DuraAce 8spd ? Could it be the wrong chain width ? If so, any idea how I can tell ?

Thank you in advance for any thoughts/suggestions !
re: DuraAce 8-spd Tuning and ChainlineRusty Coggs
Oct 6, 2003 12:09 PM
How about trim positions in the shifter? you should not be in the small/small or big/big anyway.
re: DuraAce 8-spd Tuning and Chainlinescopestuff2
Oct 6, 2003 2:19 PM
The trim works when going from small chainring to large chainring, but not the opposite direction - I get no movement even if I've go up once on the trim. Not sure if it's supposed to work in both directions.

I know I should not be crossed up on the chainline. But, I'm able to get more crossed up, quieter with my 9spd Ultegra which seems a bit more demanding than the 8spd DuraAce.

Also, I don't understand why the chain would run the large chain right when going small/small. Is that normal ? I don't believe that my Ultegra group has that problem. Has anyone else seen it before ? maybe it's just design and not a problem.

What makes me notice it is that the 8spd DuraAce is alot noiser than my 9spd Ultegra .... I'm talking about drive train noise while riding. Maybe it's just a noisier drivetrain ?

Thoughts ?

Thank you in advance !
a couple of thingsEric_H
Oct 6, 2003 4:27 PM
Regarding the small/small combo, having the chain drag on the big ring is not uncommon. On an 8spd system, the chain is a bit wider and this makes the problem worse. If the bike has short chainstays the problem will be even worse. I never ride this gear on any bike 8, 9 or 10 speed so I do not consider it to be a problem.

For the trim function on the front derailleur when using the big ring and a large rear cog, make sure the cable tension is not too tight. The STI lever should definitely have a trim position on the inner lever once the outer lever is fully pressed to engage the big ring. Adjust cable tension so the front derailleur moves completely outward when you shift to the big ring moving the outer STI lever fully inward, but so it JUST gets there (ie. it does not fall "back" from the outer limit). Too much cable tension will take away the trim function.

My old 8spd D/A was nice and quiet for many seasons. If you are having more overall noise, check your rear derailleur hangar for alignment and make the sure the the rear derailleur itself is not bent at the cage.
a couple of thingsscopestuff2
Oct 6, 2003 11:02 PM
Eric;

Thank you for the reply. I'm pretty much a nubie. It's good to know that the chain drag on the larger chainring is not a sign of impending doom - that's it's fairly normal especially for the 8spd.

I've pretty much tweaked all the deraillures, and 'b' screw on the rear. What I find now is that all is well (though much more noise than my 9spd Ultegra). However, I still rub either chainring or front deraillure when crossed with the large front and two large cogs, or small front and two small cogs. I realize that that's not a place I would stay for long .... however I do wind up there sometimes .... at least on my bike with the Ultegra. Still learning to shift properly and anticipate gears.

The rear derailleur does seem to hang properly. However, whenever I'm in the largest cog it makes a thump - thump - thump - thump sound along with the normal chain noise.

Does this sound normal ? The trim functions work properly.

Thank you again !

-Robert
re: DuraAce 8-spd Tuning and ChainlineMikeDee
Oct 7, 2003 3:26 PM
With the limit screws and cable tension set right, I never had a problem with my 8 speed DuraAce front derailler rubbing. The chain did rub the outer ring when in the small-small combination, though.

You obviously have the cable tension set incorrectly if you can't get a trim setting when in the big ring.
re: DuraAce 8-spd Tuning and Chainlinescopestuff2
Oct 9, 2003 11:03 PM
Finally found the problem. The lower pulley bearings are shot. Now I'm trying to decide whether to get a current Ultegra 9spd to replace it, or to find a matching 8spd DuraAce. Seems like the current Ultegra should do the job just fine. I don't care about the difference in grams.

Any thoughts on Ultegra v.s. finding an 7204 DuraAce to match the rest of the groupo ?

Thank you in advance !
re: DuraAce 8-spd Tuning and Chainlinesatanas
Oct 10, 2003 12:38 AM
It should still be possible to order DA8 jockey wheels from Shimano. If not, there's certain to be something else that fits. Be aware that DA8 (and before) used different cable travel to other Shimano (DA8 = same cable travel as all 9 speed Shimano).

This means that an Ultegra derailleur won't work properly unless bodgy cable routing is used, or the shift levers are replaced with 9 speed, etc.

Also, DA 9 speed derailleurs are intended to be retrofittable to DA8 drivetrains and have another cable notch at the anchor point which gives the correct travel.

I'd be buying jockey wheels....
what I did: sell that junk on e-bay!shawndoggy
Oct 10, 2003 3:00 PM
Sold all my 8 speed DA stuff and bought 9 speed ultegra (shifters, cassette, rear deraileur, chainrings, chain). Sold the old used up junk for $165; BOught all new for $225 (delivered, price matching at performance and using their 20% off coupon). Feels like I jumped into the new century! Even at its best, DA 8 sucks compared to ultegra (and maybe even 105) 9 speed.

My $.02, from a guy who has screwdriver holes in the side of his garage from tossing them in frustration after trying to get the darned DA 8 speed to shift.