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Chain Drops After Triple Upgrade(6 posts)

Chain Drops After Triple Upgrademtbnutty
May 5, 2003 10:14 AM
After installing an ultegra triple setup, I drop the chain if I'm in the middle ring and big cog (42/25) I've been through the front and rear deraileur setup twice to no avail. This is my first experience with a triple on a road bike but have built many mountain bikes with triples without any problems. All parts are brand new and all other gear combinations seem to work. Could I have a chainline problem??

re: Chain Drops After Triple UpgradeLone Gunman
May 6, 2003 5:56 PM
Where is it dropping? FD? You realize that there are four positions on the Ultegra? 1 is for the 30t ring, you must click the shifter all the way down several times to make sure you are there. The cage must be almost touching the chain to the inside of the cage, must be in big rear little front to adjust without the cable attached. Of course the next adjustment is the big ring little cog on the outside, again cage almost touching the ring, a bit more leadway with that. You should be ready to attach cable. Shifting up puts you in position 3 of the middle ring, it skipped over position 2, if you half shift the FD down it will trim you for the lower range gears (25t,23t maybe 21t cogs) the chain won't rub when in these cogs. Of course position 4 is big ring and really you can take it down to about big ring/21t and not get rub. Anything beyond that and you are stretching the limits of chain line to the point of possibly crosschaining. Riding in this position causes excessive wear on the drivetrain.
re: Chain Drops After Triple Upgrademtbnutty
May 7, 2003 9:47 AM
I've set up the front derailleur as you described. With the chain on the middle ring and the biggest cog (42/25) and no rubbing of the FD the chain rips of the chainring. This happens after approx. 20 pedal strokes regardless of pedal pressure. I can keep the chain on only if I trim the FD to rub the chain toward the big chain ring.
Something does not sound rightLone Gunman
May 7, 2003 5:31 PM
take a peek at the position of the FD as far as the position on the seatpost, perhaps loosen and twist the clamp(if it is a clamp type) to the left just a smidge. If you are certain that the FD is not causing the chain to drop off and it is coming off the ring, look for simple stuff like a stuck link in the chain or (gasp) a bent or misaligned frame. Ultegra triple stuff works pretty smooth, should not be doing what you describe. Worst case scenario, take it to a shop and have them figure it out.
Turn the crank backwards and watch...TFerguson
May 8, 2003 3:58 AM
for the rear derailleur pulleys to jump indicating a bad link.
Something does not sound rightmtbnutty
May 8, 2003 7:57 AM
I'll check the FD alignment tonight one more time. Maybe the FD is mounted too high and lifts the chain a bit in the middle ring. This may not be visible when I'm riding and looking down. My frame is less that 1 season old and I've never hopefully I don't have a bent frame...$$$$$$$ouch! BTW, thanks for all the help here. I'll post again after tweaking things tonight.