SLX front 2sp mech, over-shift, will I die?

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  • SLX front 2sp mech, over-shift, will I die?
  • Premier Icon stimpy
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    Sounds like you haven’t set the high and low limiter screws properly? Put into each chainring and set high and low limiter screws so the cage moves enough to shove the chain on to the appropriate ring but no so far that it comes off?

    dantsw13
    Member

    You say “middle Ring” are you using a 2x front mech on a triple?

    It may still work. sounds like you need to adjust the end stop, so the spring pulls the mech closer to the small ring.

    Premier Icon stimpy
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    As expertly indicated by top quality illustration:

    Premier Icon bails
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    I’ve tried the slack cable trick, which works

    So do that…. I do on a converted triple chainset and my 2×10 xt mech works fine.

    Cranks are SLX 2×9 The limiter screws are set but the shifter won’t even get to the first ‘click’ before the limiter stops it, it’s as though the shifter is pulling too much cable.

    I know I can use the slack cable method but surely that’s not right. the shifter shouldn’t need to pull some cable through before the mech starts to move?

    Premier Icon bails
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    It works, so what’s the problem?

    supersaiyan
    Member

    Have a look at the cable routing again. I have had this before when I routed the cable on the mech incorrectly

    Premier Icon stimpy
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    What supersaiyan says ^^ – I was about to say cable routing too – I’ve got a SRAM direct mount on the front and the cable routing is mental.

    Shimano seem to think this for the SLX direct mount:

    Or:

    I got myself an SLX 2sp direct mount, top-pull, front mech as I’m crap with 1×10. Using a 2sp shifter, however, it seems to ‘over-shift’ knocking the chain off the middle ring before the shifter even clicks. I’ve tried the slack cable trick, which works but that seems a bit crap. Tried different shifters with the same laboratory (my shed) results. Am I being daft? Will I die? Your thoughts, as ever, are appreciated… GO!

    Premier Icon cookeaa
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    Cranks are SLX 2×9 The limiter screws are set but the shifter won’t even get to the first ‘click’ before the limiter stops it, it’s as though the shifter is pulling too much cable.

    sounds like too much cable tension then, dial it down or if you have to let the mech rest on the (correctly adjusted?) Low stop undo the cable clamp and let a bit of the tension off, re clamp it and try again…

    Question: You are using all SLX 2×9 parts (Mech & Shifter) and not mixing a Dynasis 2×10 part in somewhere are you?

    For my own part I didn’t bother with a double specific shifter I’m using an SLX M665 Top Swing 2×9 Front Mech with an old LX 3×9 shifter without issue.

    – “Top” shift on the shifter aligns with “Middle ring on the crank. – “Middle” on the shifter translates to Granny on the crank.
    – “Inner” position of Shifter just pays out slack cable and the mech sits on it’s low adjuster…

    Never quite understood why you’d pay more for a shifter with fewer clicks…

    Bails, I know it works, I’m wondering if it’s something I’ve done/not done, surely it should work without having to pull some slack through first.

    Supersaiyan, it’s a complete run outer cable, the only stops are the shifter and mech dude.

    I know on the new SLX shifters come with a a little switch so you can change from 3×10 to 2×10 but I don’t think that changes any pull of the cable, it just stops after 1 click.

    Cookeaa, it’s a new mech as I had to get a direct mount so it could well be dynasis and I’m trying old shifters, does the dynasis pull less cable? so if I’m using an ‘old’ shifter, is this pulling to much cable through

    Premier Icon stimpy
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    OP I don’t think you understand the point supersaiyan (and I) are making – ‘check the cable routing’ means ‘check how you’ve attached it to the derailleur’ as per the technical illustrations I copied from Shimano’s website for you.

    Also – cookeaa’s question – you mention you’re using 2×10 shifters but 2×9 cranks. Are you mixing 2×9 and 2×10 shifters/mechs? I don’t think you can since the pull ratios are different. All nine-speed or all ten-speed, but you can’t mix them (as far as I know).

    Premier Icon stimpy
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    Aaah – I reckon that’s it. Your ninja reply cut across my last post – you can’t mix a 2×9 shifter with a 2×10 mech since the pull ratios are different (yes, the shifter is pulling the ‘wrong’ amount of cable for the mech).

    That could be it, I have a set of SLX ‘Dyna-sys’ shifters, (which I didn’t really want to have to use/buy) so I will try that. I was hoping I could have used a shifter from the spares box!

    I really didn’t think that 2×10 and 2×9 would be any different as nothing really changes up front. Trust Shimano to throw a required change into the pot!

    Thanks lads!

    Premier Icon Scapegoat
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    Couple of things to check. As Cookea says, the mech and shifters need to be either both Mega9 or both dynasis.

    If they are both of the same sort wedge the mech open at biggest ring using an allen key. Check that the cage lines up parrallel with the big ring. Adjust its height if you can with the direct mount so that it just clears the bash if you have one. Check that the inside of the outer plate clears the chain by 1mm or so with the chain on the outer (middle) chainring and smallest cog on the cassette.

    Take out the allen key and let it spring back to low. Adjust the limit screws so that the inside plate of the cage misses the chain by 1-2mm in the biggest cog on your cassette.

    Shift your shifter to bottom before adding cable. Whether it’s a triple or 2 speed shifter, you need to index it so it’s pulling cable from granny to middle as you shift, not middle to big.

    Add cable, and make sure you clamp so that the cable goes into the groove under the clamp bolt. Pull down on the cable as you clamp to take up any slack.

    Now, shift onto the big ring. It should be indexed at this point, but may need some fine tuning with the limit screws to make sure the chain doesn’t foul the inside of the mech cage in big/little or granny/big.

    If it’s a converted triple chainset avoid running granny/little, but you should have free rein to work alll the cogs in the middle ring, so check for fouling in big/big as well.

    Premier Icon Scapegoat
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    Crossed in the post!

    dantsw13
    Member

    As an interim fix, if you allowed a little slack cable when in the little ring, then the first part of lever travel will take up the slack, allowing the remainder to push the mech to the stop – if that makes sense?

    Premier Icon cookeaa
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    Dynasis Front Mechs use the same Pull ratio don’t they? only they are intended to shift a narrower pitch with a slightly thinner chain, I could be wrong, no doubt someone will correct me, best way to confirm is to find the mechs Part Number (M???) and google it.

    TBH I don’t quite know what you mean by the “Slack Cable Trick”…

    This is my Routine for adjusting a front mech:

    I tend to get the granny position sorted first with no cable attached; check I’ve set the Low limit such that the chain doesn’t rub throughout the required range at the back.

    Then I connct the cable with the shifter set in it’s “Granny” poition and the barrel wound about 1.5-2 turns out (in case I want to let a little tension off of the cable later).

    I then pull the cable through using a pair of grips on the very end of the cable (which I will be clipping off later), clamp it, then try the up shift with the high limit screw wound out, check I’ve got no rubbing (adjust the cable tension as required if if I do).
    When I’m happy I wind in the High limit screw till it just touches then back 1/8th of a turn.

    Cycle the gears through their shifts front and rear a few times in both “Granny” and “Middle” until I’m happy they work and no unwanted rubbing is occuring, then Clip the cable and fit a ferrule.

    does that make sense?

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

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