Road Cycling - Why does my ultegra rear derailleur suck?

Just wondering if anyone has thoughts on this... I just bought a new Trek 5200 with full ultegra. I love the bike, however the rear derailleur completely sucks. And by sucks I mean it will not keep a gear. I will put it in the 4th ring of the cassette and it will jump to the 5th, I shift it back and it jumps to 3, then I shift to 4 again and it repeats. This happens consistently. Also in the 5th ring when i get out of the saddle to dance up a hill, it will jump gears as soon as I pound on it to take off. This is scary, I don't want to bust my knee on my top tube or something. Anyway, I am taking in this afternoon, but wanted advice as to whether this sounds like adjument or whether I got an Ultegra with a twist of lemon.
Thanks...

not tuned right, take it back to the shop and ask them to adjust it correctly.

Sounds like it needs adjustment. Things that work in the shop don't always work under load. Let the shop have a crack at it before making lemonade.

I have about 8500 miles on a bike with an Ultegra RD. It has been absolutely flawless for the first 8400 miles. I've just noticed a similar circumstance to what you describe. However, I seriously doubt that it is my RD's fault. After having dissasembled the rear RD STI shifter, cleaned it, lubed and reinstalled it, I am convinced the problem is in the shifter. I have a new STI shifter set on order and will probably install them in the next couple of weeks.

Just wondering if anyone has thoughts on this... I just bought a new Trek 5200 with full ultegra. I love the bike, however the rear derailleur completely sucks. And by sucks I mean it will not keep a gear. I will put it in the 4th ring of the cassette and it will jump to the 5th, I shift it back and it jumps to 3, then I shift to 4 again and it repeats. This happens consistently. Also in the 5th ring when i get out of the saddle to dance up a hill, it will jump gears as soon as I pound on it to take off. This is scary, I don't want to bust my knee on my top tube or something. Anyway, I am taking in this afternoon, but wanted advice as to whether this sounds like adjument or whether I got an Ultegra with a twist of lemon.
Thanks...

Though probably an adjustment issue, it could also be that there's a tight link in your chain somewhere compounding a minor adjustment issue.

Your rear derailleur does not suck. Learn to tweek those little cable adjusters. It's not rocket science!

Your rear derailleur does not suck. Learn to tweek those little cable adjusters. It's not rocket science!

I agree with Fixer. It's very simple to make minor cable adjustments. You should learn to do it yourself, so you don't have to waist good ridin' time by taking your bike to the LBS everything the cable needs a simple adjustment.

Start here: http://www.parktool.com/repair_help/FAQrindx.shtml

or take your bike to the LBS and ask them to show you how to do it as they are adjusting yours. It's a matter of turning the adjustment barrow one way or the other...very simple. Good luck.

how old is that chain and are the teeth of that cog worn on the cassette?

Your rear derailleur does not suck. Learn to tweek those little cable adjusters. It's not rocket science!


Don't listen to him, he dosen't have a derailleur! :D

Yep just and adjustment, an easy one at that. The tight link thing could be valid. Also an easy check.

Don't listen to him, he dosen't have a derailleur! :D

Yep just and adjustment, an easy one at that. The tight link thing could be valid. Also an easy check.
Thanks for the feedback everybody! I do need to learn how to work on them myself, just need to find the time to learn.
Cheers,

Just wondering if anyone has thoughts on this... I just bought a new Trek 5200 with full ultegra. I love the bike, however the rear derailleur completely sucks. And by sucks I mean it will not keep a gear. I will put it in the 4th ring of the cassette and it will jump to the 5th, I shift it back and it jumps to 3, then I shift to 4 again and it repeats. This happens consistently. Also in the 5th ring when i get out of the saddle to dance up a hill, it will jump gears as soon as I pound on it to take off. This is scary, I don't want to bust my knee on my top tube or something. Anyway, I am taking in this afternoon, but wanted advice as to whether this sounds like adjument or whether I got an Ultegra with a twist of lemon.
Thanks...

Not to scare you but that kind of gear jumping around could mean a bent derailer hanger or a bent derailer.

Could it be the cable tension-have had them do something like you describe when the cable is too loose.

Why does my Ultegra rear derailleur suck?
Because its not campagnolo? :D

Because its not campagnolo? :D
Ah geez Marty, give the kid a straight answer! :D

Ah geez Marty, give the kid a straight answer! :DThat was a straight answer! :p

Try a half turn counter clockwise on the barrel adjuster on your rear der. If it gets a little better but still shifts bad, try another half turn counter clockwise.