Viewing 19 posts - 1 through 19 (of 19 total)
  • drivetrain problem – front mech clearance
  • sadexpunk
    Full Member

    just built up my jake the snake ready for commuting, but im not happy with the gears.

    cant seem to get the right clearance from the mech, and also the shifters arent working as id like. heres the pic

    if you look close enough youll see the campag crank, is only just missing the front mech towards the rear. yet the chain is still catching on the mech at the front. obviously i cant twist the mech or move it out for the chain to clear, as then itll hit the crank :-/
    its a campag mirage chainset, campag veloce mech, and campag bb.

    also, whether its related or not, when im on front ring, it takes about 3 clicks to get it onto small ring, and then i have to do 1 click back to stop chain catching on mech again.

    any ideas? (new cable and outers btw)

    khani
    Free Member

    Looks like the bottom bracket is too narrow, what size axle is it

    cynic-al
    Free Member

    Can you rotate the mech so that the front and rear of it’s outer cage clear the crank by the same amount?

    Doesn’t look compatible tbh, is it all from the same year, meant for the right crank etc?

    crispedwheel
    Free Member

    also, whether its related or not, when im on front ring, it takes about 3 clicks to get it onto small ring, and then i have to do 1 click back to stop chain catching on mech again.

    ^that doesn’t sound right at all – what shifter are you using?

    sadexpunk
    Full Member

    khani, that was my first thought, but if you think about it, whatever size the bb is, its pushing everything out or in at the same time. its not going to affect the front/rear clearance of the mech :-/

    the mech as a bit of a bulge built into its shape, and the crank seems to be struggling to clear that.

    mech is rotated so its in best position for both chain and crank. any more to clear the crank, and the chain rattles against it 🙁

    dont know about same year, but youd expect campag to be compatible with campag? :-/

    shifters are sora. indexed right? how can i alter the indexing?

    thanks

    khani
    Free Member

    also, whether its related or not, when im on front ring, it takes about 3 clicks to get it onto small ring, and then i have to do 1 click back to stop chain catching on mech again.
    ^that doesn’t sound right at all – what shifter are you using?

    Sounds like a triple front shifter and a double chainsett
    I’m probably wrong though

    sadexpunk
    Full Member

    think the shifter actually has more than 3 clicks. was thinking that was deliberate so you can adjust it slightly if chain is catching. am i wrong there?

    didnt actually know you got ‘double-specific’ shifters :-/

    khani
    Free Member

    dont know about same year, but youd expect campag to be compatible with campag? :-/
    shifters are sora. indexed right? how can i alter the indexing?
    thanks

    I didn’t think sora was compatable with campag

    sadexpunk
    Full Member

    hmmm is that right? is it like shimano/sram then? different cable pulls?

    khani
    Free Member

    didnt actually know you got ‘double-specific’ shifters :-/
    My road bike has double front shifters for the double chainsett (ultegra)
    They are different than the triple on the wifes bike

    cynic-al
    Free Member

    You should be able to get the sora to work “OK” IME, but it looks to me like the mech and cranks are incompatible.

    sadexpunk
    Full Member

    yeah, think youre right there.

    what sort of mech should i look out for do you think? the cable comes up from under the bb shell. is that ‘bottom pull’? and top swing? bottom swing? i get confused with bottom bracket terminlogy 🙂

    cynic-al
    Free Member

    I’d get one from the same campag groupset & year, just to be sure. All road mechs are bottom pull and bottom swing (i.e. both are irrelevant)

    sadexpunk
    Full Member

    thanks mate. problem is, i dont know what year the crankset is 🙂

    ajf
    Free Member

    Oh I got this problem as well! Campag veloce throughout but still catches.

    Does it seem that the gap between the crank arm and the large ring is too small? therefore the derailluer does not fit as it is either touching crank or touching chain?

    You manage to fix or work it out? I went for ensuring that the chain catches only when in top gear and 2nd to top gear. All the rest are now smooth but it is a compromise as I cannot work out how or why it wouldn’t work.

    Tracker1972
    Free Member

    Surely a longer axle would reduce the angle to the higher gears so “might” solve the problem. Should at least lessen it?

    missingfrontallobe
    Free Member

    I seem to recall a similar problem when I set up a bike a few years ago, the front mech cage would catch the inside of the crank arm when the chain was on the outer ring – seem to recall it was all my mistake, and I’d simply been too hasty to set things up. Stripped eveything down, and went at it again slowly & steadily, especially when it came to adjusting the front mech stops.

    sadexpunk
    Full Member

    got someone else to check it over, and they agreed it was strange but id done the best i could with it, and it just wouldnt work ok.

    so ive bought a second hand shimano mech now. waiting for it in the post, so ill update you on whether its any better once its fitted.

    cheers

    cynic-al
    Free Member

    some mechs have no crimping on the outer plate which helps in this situation. can’t say off hand which ones!

Viewing 19 posts - 1 through 19 (of 19 total)

The topic ‘drivetrain problem – front mech clearance’ is closed to new replies.