Shifting up gears- just can't get it smooth!

adamdavi3s
adamdavi3s Posts: 280
edited April 2011 in Workshop
This is officially doing my nut in and I can't think what else to check.

The missus bike is running full ultegra.
The mechs, chain, cassette etc are 1500 miles old MAX

Towards the end of our last ride it started to 'jump' when changing up gears (large cog -> smaller cog), however the changing down remained smooth. Prior to this is was silky smooth!!

So, get it on the stand and get it changing smooth ish both ways but as soon as it gets pressure on the system while riding, it starts to jump down again.

So Immediate thought is that the hanger is bent, drop it to the LBS who confirm it is slightly so they straighten it and apparently adjust the mech, however they obviously didn't ride it as it still has the same issue when being ridden.

I've changed the cassette to a new one
The jockey wheels are still in very good condition
The cables have max 300 miles on them so are in good nick
B screw is set correctly
H & L are set correctly
Chain length is correct

Comments

  • Have a look at this video.

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

    I think its unlikely that any of the kit is at fault, its more likely to be an adjustment issue.
  • adamdavi3s
    adamdavi3s Posts: 280
    Yes thank you for that video, I am perfectly aware how to adjust the gears thank you.
    I am also hoping that my LBS are at least slightly informed as how to do this as they employ three mechanics!

    This is the reason I thought a component must be at fault
  • Tom Butcher
    Tom Butcher Posts: 3,830
    Suppose you could try a new chain - nothing lost as if that doesn't solve it you can always put the old one back on and keep the new one for the future. If it's jumping back down after shifting up could there be something wrong with the shifters - maybe it's pulling enough cable to change up but then letting a small amount back out again.

    it's a hard life if you don't weaken.
  • adamdavi3s
    adamdavi3s Posts: 280
    I think I might have to try a new chain, but I'd be surprised if it was that worn already!

    Not not jumping in and out of gears at all, just on a few at really jumps /clunks into gear which is annoying!
    I've serviced the other three bikes this morning and they're silk smooth now, this one is just vexing me!
  • turnerjohn
    turnerjohn Posts: 1,069
    could have a stiff link in the chain...other then that gear set up sounds the issue here.
  • adamdavi3s
    adamdavi3s Posts: 280
    Yep checked that one!
    Each link is fine and dandy!
  • desweller
    desweller Posts: 5,175
    Increase the length of the rear housing loop to the derailleur. It's quite easy to get this too short; as it's the tightest radius the cable will follow, it will have the greatest effect on shifting quality when the internal sleeve starts to wear out. The wear rate of the internal sleeve is greatly affected by the radius of the loop.
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  • dabber
    dabber Posts: 1,937
    inner cable sticky in the outer?
    “You may think that; I couldn’t possibly comment!”

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  • adamdavi3s
    adamdavi3s Posts: 280
    Yep I've put a new loop on which is really quite large (yes using proper cable cutters!!), the flow of the cable appears very smooth the whole length of the system
  • pastey_boy
    pastey_boy Posts: 2,083
    sounds to me like a cable issue, its smooth going up the block but may be hesitating coming back down causing it to jump between cogs, tiniest bit of crap in your outers can cause this.
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  • ride_whenever
    ride_whenever Posts: 13,279
    pastey_boy wrote:
    sounds to me like a cable issue, its smooth going up the block but may be hesitating coming back down causing it to jump between cogs, tiniest bit of crap in your outers can cause this.

    ^^this
  • adamdavi3s
    adamdavi3s Posts: 280
    Hmm ok I'll flush the outers at the shifter end also
  • jermas
    jermas Posts: 484
    Like others have said, it sounds like a cable problem. Silicone grease on the cables can help. Also have you tried lubricating the rear derailleur pivots.
  • adamdavi3s
    adamdavi3s Posts: 280
    Yep first thing I tried when it still didn't work after having the hanger straightened

    New inner + outer cable and the problem persists.

    I also tried a newer chain and still the same issue.

    I think I am going to dry another mech on the back and see if that helps
  • adamdavi3s
    adamdavi3s Posts: 280
    OK tried a different mech and same issue.
    Also tried indexing without the cable attached and it jumps still
    i.e. from the smallest cog index it down with my thumb, this is nice and smooth, let go of the shifter and it 'jumps' into gear, so exactly the same as when the STI is indexing.

    The only thing I can now think is that the hanger must still be out but it looks OK and as if everything is still aligned...
  • jermas
    jermas Posts: 484
    Sounds like a very frustrating problem you've got there. One other possibility- is the cassette tight on the freehub (no sidways movement). If it's 10 speed it needs the spacer fitted.
  • adamdavi3s
    adamdavi3s Posts: 280
    Hmmmmm yes I've managed that once before when I was in a rush!
    It's nice and tight though!
  • rake
    rake Posts: 3,204
    check the cable guide under the frame, if its picked up dirt or grease thats dried out it will make the cables sluggish. Is the cable routed the correct side of the pinch bolt on the mechanism, it could alter the leverage ratio and movement slightly. it could be a clue that its only doing it going to a smaller cog which is purely the spring assisted movement, as opposed to being pulled by the cables going in the other direction. other things to look at are the freehub bearings, frame cracked. The bare sections of cable use the frame as a stop, so if the frame cracks or bends somehow it can alter the lenght of the cable.
  • adamdavi3s
    adamdavi3s Posts: 280
    Yep checked all the cable routing!
    Also tried a different wheel!!

    I'll double check the frame tomorrow but i'd be worried if it was cracked as it'd only a couple of hundred old!
  • rake wrote:
    check the cable guide under the frame, if its picked up dirt or grease thats dried out it will make the cables sluggish..

    Good shout. I've got a Trek which the happens to. Bit of grease and jobs a goodun.
  • adamdavi3s
    adamdavi3s Posts: 280
    Yep but I can't get a smooth shift even without the cable.
    Again moving it manually shifts smooth down but not up
  • adamdavi3s wrote:
    Yep but I can't get a smooth shift even without the cable.
    Again moving it manually shifts smooth down but not up

    When you say that it doesn't shift smoothly, do you mean that it just hesitates before it shifts?

    Apart from trying a different cassette, it looks like you've eliminated everything.

    It still could be the rear mech hanger, but I can't see how that would affect the shifts without any friction. My experience of a bent mech hangar was that the gears shifted, but the shifts were not precise and and at the top of the cassette on the easier gears there was noise you couldn't get rid of even by adjusting the tension. If you removed the noise at that end of the cassette, it would appear at the other end.
  • adamdavi3s
    adamdavi3s Posts: 280
    Nope tried that too!
    No it doesn't seem to hesitate, its not hanging before shifting down its just really clunking / jumping / slamming into the next gear, although its only on a few sometimes they work sometimes they don't which is why I pondered the hanger still being out.
    When actually riding you get that moment of slack before it picks up again in the new gear.

    Funnily enough I am getting a noise at the bottom end which I can't clear out.

    So far:
    Changed cassette
    Changed cables
    Greased ENTIRE cable line
    Increased cable loop at the rear
    Decrease cable loop at the rear
    Tried a 10 mile old KMC chain
    Tried my DA rear mech

    I think tomorrow I'll just drop it to the LBS again to look at the hanger as I've spent about 8 hours on the damn thing now!
  • You've spent about 7-hours more than I would have without slashing your wrists!!!

    With my experience of Ultegra 6700, I would deffo stick with the 6700 chain. My bike came with a cheap Sram chain and crap cables.

    Changed the chain to a 6700, installed a Jagwire racer kit and instantly awesome shifting without pissing about too much with the indexing.

    I know a lot of bods on here swear by KMC chains and the like, but in my experience I've always had he best results with the correct groupset series parts.

    The guy who sorted out my mech hanger, has got this tool:

    http://www.parktool.com/blog/repair-hel ... -alignment

    Having said that he didn't use it, and just adjusted by eye. Needless to say that I trust him with my life when it comes to any bike problems I can't solve.

    The description you've given about the symptoms of your problems, makes me think that it needs to bed it, on the other hand that doesn't make sense as the shifting before was good!?

    Good luck at the LBS tomorrow!
  • adamdavi3s
    adamdavi3s Posts: 280
    Its 6600 (except 6700 sti's) and a full jagwire kit.

    As you say, it was running really nicely before and for a good amount of time, just until 1/2 way through the last ride.
    Riding up here on Dartmoor there's a lot of pot holes / cattle grids so its possible something somewhere has gone ping or crunch but I am buggered if I can find it!!

    The only thing I can now think to check is the mech alignment
  • Did you get this sorted?
  • adamdavi3s
    adamdavi3s Posts: 280
    No its back with the LBS who seemed offended to have it back!
  • on-yer-bike
    on-yer-bike Posts: 2,974
    Has the mech hanger been bent and re straightened? Even if it hasnt, to your knowledge, it may be worth replacing it to one made by Wheels Manufacturing. If the hanger is too flexy gear changing is awful. It seems to be the only thing left to try!
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  • adamdavi3s
    adamdavi3s Posts: 280
    Yeah that is why it went in to the lbs in the first place!
    If it's still poor when I get it back i'll get a brand new hanger!