Ultegra Issues

Oscarcat

Hi all,

Saved up for ages and finally bought for a brand new carbon frame with full ultegra 6800 about two weeks ago. I was dead chuffed.

Unfortunately though, I took the advice of a friend who decided that I should plump for a 52T 36T front gear set, with 11-28 rear cassette.

I was previously used to a 50T 34T, and 11-28, and have struggled to enjoy my new bike-I feel like I'm in between front cog gears.

Rueing my mistake of listening to the expert I decided to buy an ultegra 50T 34T and direct replace, I didnt replace the rear cassette. The front swap went well and pretty easy, but since then the rear derailleur just feels like it's constantly trying to change gear, giving that clicking noise you get when its not quite made gears. I've tried to tune/adjust the rear derailleur and it's still doing it. I'm absolutely gutted as I can't figure out what's up with it.

I'm thinking it could be chain length? The bike came with 116 link chain, does it need to be 114 when you change the front gear Set?
Incompatible rear derailleur-which would be odd given ultegra appear to pride themselves on compatibility
Bad adjustment of rear derailleur.

Any suggestions guys?

Thank you

arlowood

Using the chain length calculator here

http://www.machinehead-software.co.uk/b ... hcalc.html

suggests that switching from a 52T to a 50T front chain ring should need no change in chain length.

So either your indexing is out - in which case I suggest you check out this video for the best approach to set-up I've come across

https://www.youtube.com/watch?v=SkzvfCaIbyQ

One other possibility is that the chain line may be out slightly if you did not install the new chainset properly. In my experience some Shimano chainsets can require a bit of "persuasion" with a mallet to get them to fully seat against the BB bearing on the drive side. Check yours to make sure there is no gap and if there is, loosen off the NDS crank arm and give the drive side a good whack with a wooden or rubber mallet to get rid of any gap. Then refit the NDS crank as normal.

Oscarcat

Thank you. The chain thing has put my mind at rest.

I've given the front gear set a more firm whack and tellingly the front derailleur is now rubbing on the chain more than it was before, so my guess is that it wasn't in line either. Thanks, I wouldn't have thought of that.

I'll have another play with the derailleur, but will take it into the shop if it doesn't seem right.

Thank you.

cycleclinic

It is a setup issue. Chain length will have become 0.5 inch shorter probably no change needed but the rest is simply indexing of the gears and front mech alignment.

jermas

As above,the chain will most probably be too long (but doubtful that would give you the problem described). Also check you have the chain installed in the correct direction -some (shimano) have to be the correct way round- with the lettering facing out. Also the front derailleur will need setting up (lowered) as the chain rings are now a smaller diameter.

Oscarcat

Thanks for those messages. I had another go this morning, but couldn't quite get it right. Found a pro workshop nearby that'll sort front and back gears for £15 (but I'll be checking it before paying!), so I'll go down that route for now and then at least I know it's sorted following the front hub change.

nuclearred955

Have you reset your B-screw since swapping rings? Could well be that - it regulates the gap between top jockey wheel & cassette, and will need to be adjusted to compensate for the slightly slacker chain you now have.

Stick it in small front/small rear combination & tweak the B-screw to get the jockey closer to the sprocket. It'll likely be a balancing act with maintaining chain tension, but it should help it run quieter.

keef66

Just for info, your chain may have had 116 links when it came out of the packaging, but it would have been shortened to the correct length when fitting.

As above, 2 teeth fewer on the biggest chainring is unlikely to mean that you need to shorten your chain, unless it was too long to start with...

keef66

"I've tried to tune/adjust the rear derailleur and it's still doing it"

If it's just the indexing of the rear mech, that should have sorted it. Assuming you were tightening / loosening the barrel adjuster and not doing anything with the limit screws?

Oscarcat

Thanks for help.I chatted to my friend about it and we're done I think.It just needed lots of balancing every screw and bolt as you said and he knows more than I do so it was easier.he wants to try the old 52/36 as it might suit him anyway,so it worked out ok.