ste4en

I have a Cannondale Super X, Ultegra carbon cross bike. Three years now and it has never shifted smoothly. LBS have had several goes at it, better but never just right. Most recently visit was a new hangar bracket and a new bottom bracket. No real improvement.

I recently replaced the rear derailleur and the cables. Still issues. Just never smoothly in a gear (well maybe one) but usually always noisy, indexing seems out, sometimes struggles to change then at next click jumps two gears. I have watched numerous YouTube videos on how to adjust the derailleur and I am quite sure I am doing that part correctly.

So to troubleshoot further I removed the front derailleur, leaving the chain on the large chain ring. Still noisy. While riding the last few days the chain has come off the from the front chain ring - when I am shifting to a smaller rear cog the chain came off to the pedal side, and once when shifting to a bigger gear it came off frame side. Is this a symptom of something?

Any ideas? ......please

corrado33

Did you buy the bike used? How old is the cassette and chain? Did you replace the housing when you replaced the cable? What kind of shifter are you using? Is the cable guide under the BB clean?

Yes, it is a symptom of something. It's called cross chaining, and you shouldn't do it. Look it up. The front derailleur is there for a reason. Not just to shift, but to also keep the chain where it should be.

Why you would remove the front derailleur to troubleshoot the rear derailleur is beyond me.

techsensei

I cannot say what the problem is. When the new hanger was installed, was it checked for alignment? Also, try looking at Park Tool's guides on adjustment: Repair Help Articles | Park Tool

It is a symptom of removing the front derailleur. The chainring is made to make it easy for the chain to come off; it has ramps so it can shift smoothly. Putting the front derailleur back on will prevent the chain from falling off.

AlexCyclistRoch

Two things you need to check:

1) Is the hanger bent?

2) Is the shifter defective?

Also, sometimes shifter cables run under the tape causes issues. If this is the case, you may need to upgrade to a Teflon-coated cable housing.

ste4en

I bought it new in Oct 2013 - chain and cassette never replaced. I ride maybe 1,000 miles a year. It is an Ultegra shifter. I remove the from derailleur out of desperation since I was never sure if it was the front or rear making the noise.

I will put it back - then follow some of the suggestions being made.

thanks

berner

I'm no expert but can think of several possibilities for your problem. One is a mismatch of the derailler - say a 9 speed on a 10 speed cassette. The second possibility comes to mind because I had this problem. The bushing in the derailler that permits pivoting is worn or was poorly machined in the first place. In my case I had poor shifting and no amount of adjustment over a period of weeks helped. I noticed that the derailler had a lot of lateral play so that the jockey pulley was very floppy side to side. A new derailler solved the problem and has been fine for the last 4 years. Good luck.

deapee

Well, sorry that I can't offer much mechanical advice on how to fix it, but I just wanted to chime in that with the ultegra, you should barely know you're dealing with 'mechanical components' when it's working. You should just shift, it should go, and should be buttery smooth (assuming you're not shifting under load, etc). It should just be something you don't have to worry about -- I bet there's a bike shop you can take it to that will adjust it right up and it will work flawless, or at least someone that can tell you what's wrong with it.

techsensei

10 and below doesn't matter, but 10 vs 11 does. So if the bike originally had an Ultegra 6700 derailleur, and the new one is a 6800, that would explain the current issue of poor shifting. It would not explain poor shifting prior to the replacement.

ste4en

It is an exact replacement. The new one was hopefully going to fix the original problem. it didn't.

headasunder

when all the adjustments and tweaks fail its time for a new cassette and chain

tcpasley

+1 on the chain, and probably a cassette. Also check the B-tension adjustment on the rear derailleur (LBS should have done that).

FWIW - I seen to get good shifting with SRAM chain/cassette combinations.

dsbrantjr

The first thing to check when you have intractible rear shifting problems is your derailleur and hanger alignment. Just because it was replaced does not mean that it (and/or the frame where it mounts) is straight.

Flinstone

Not entirely true. I've been saying it often, because it's new and people need to start being aware of it more (and it will surely only trickle down more in time): The 2016 tiagra 10 speed derailleur, rd-4700, uses a traditionally 11 speed pull ratio. You can put an rd-4700 in an 11 speed setup, but you can't put an rd-4600 in a 2016 10 speed tiagra setup.

Camilo

Try a different bike shop and mechanic. A competent mechanic should be able to easily, in an organized way, figure out exactly what is wrong and quickly fix it for cheap (not including parts).

Like others said, Shimano (and really, any other) shifting should be perfect, and it's not difficult to make it perfect. I don't know the shop you've dealt with, but from your description of what they've done, I am not impressed.

Any competent mechanic should be able to very easily, quickly and cheaply figure out which of the likely culprit is: shifter itself, derailleur itself (function or compatibility), derailleur adjustment, cable condition or routing, hanger alignment, cassette condition, chain condition.

This isn't rocket science. You could figure it out yourself with some experience, but really, the shop should have fixed it within a month of you buying it from them.

That they sold you a bike that never shifted well and didn't fix it the first time you brought it in is, in the immortal words of Fielding Melish, a travesty of a mockery of a sham of a mockery of a travesty of two mockeries of a sham.

Seriously, find a different shop and pay them $25 (plus parts, if needed). It should be a no-brainer for any half-way competent bike mechanic.

KD5NRH

Demonic possession. Sink your entire drivetrain in the ocean and start over from scratch.

ste4en

I purchased from a bike shop in a big city and its a real pain to get to for adjustments. Lesson learned - buy from the closest or nearly closest bike shop to home - any buy the brand that they carry.

So as it happens I tried to refit the front derailleur and noticed that the mounting is cracked/broken (riveted type), which might have explained some issues I had with that. So headed to store today to get that replaced and will let them have another go at proper adjustment.

Thanks

corrado33

Any bike shop will fix almost any bike. Take your bike to your local (closest) bike shop for adjustment.

andr0id

Stuff to check

Mismatch of shifter, cassette, RD and chain. All need to be 10 or 11 speed, no mix/match. You can mix/match within 10 speed though.
Nothing bent, broken or crashed, Shifter goes click, click, RD moves smoothly. You may want to take parts off the bike to clean them and make sure they all work smoothly.
Check jockey wheels for wear and smoothness
Chain should not be worn out
Check RD hanger alignment
Cassette is tight on the freehub body, doesn't wiggle, has correct spacer(s) behind it as needed.
cable housing routing, needs to be smooth, no S bends, not too long, not too short
Cable guide under the BB (if there) should be smooth and not binding, these get worn and can create a lot of drag

Disconnect everything and trouble shoot each section of housing by itself. Grab a bit of cable at each end and work it back and forth and make sure there is no binding.

I think that's about it, otherwise I'll go with the demon possession thing.