SRAM Apex 1 downshifting problems

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  • Sorry if this is covered elsewhere, but I've got a new bike with SRAM Apex 1 and I can't get it to shift properly.
    Problem is, I can go all the way up to the big cog no problem, but going back down I get no tension, missing one or more shifts until it goes down all of a sudden.
    Anyone else got this? I tried to index it and set the limit screws, but it's still having the same issues.

  • Sounds like a frayed gear cable in the shifter. I would be surprised if that is the issue if it’s a new bike.

  • Sounds like the inner cable is getting caught. Possibly too tight a bend around the bars or perhaps under the bb the cable is not routed correctly through the plastic guides.
    If you put it on a stand and get it into the biggest cog. Release a couple of clicks without moving the cranks.
    If the rear mech does not move outwards then...
    If the cable running down the downtube does not go slack then the issue is in the lever or around the bars.
    If it goes slack and the rear mech does not move then check the routing under the bb and through the outer cable by the mech.
    I’m sure there’s other ways of checking but this works for me most times.
    It’s not unusual to go up the cassette but not down. Up and you are providing the force via the lever. Down and you are reliant on the spring in the rear mech which does not Have as much force.

  • Could be cable not seated in shifter. Could also be the inner cable is kinked at some point. Could also be if there are loads of extra rubber “johnnies” to seal the outer, they add a lot of friction. First step, remove and inspect then reinstall the innner.

  • Sounds like there is binding in the cable, take it back to the shop and get them to sort it. If you mechanically minded and I'm assuming it's a cross/gravel bike fit Jagwire sealed cables, they're well worth it in the long run, other wise the run of out from the rear mech just gets full of crap and ends up binding there.

  • I'll have a look at the routing and put some fresh inner tomorrow, see if that works.
    Could it be the chain is short? Honestly, clutches and 1x drivetrains are alien to me, my last MTB was 3x9

  • Easiest way to check if it’s the cable or shifter is to disconnect the mech and see if it shifts properly when pushed directly and released by hand.

  • If the chain was too short it wouldn't shift in to the lowest gear without doing some damage, probably to the hanger.

  • Just a word of warning on the limit screws, don't fuck about with them unless you know what you're doing, a friend of mine thought they were the reason for his poor shifting, he chucked his chain over the big ring went over the bars, and ended up needing a new spoke, chain and jersey, luckily the landing wasn't too bad. After all that it was a bent hanger. He also changed the BB on the same bike 3 times because he thought it was creaking, and it was the stem.

  • Aye aimlessly fiddling with limit screws is a one way ticket to new mech town.

  • https://www.parktool.com/blog/repair-hel­p/rear-derailleur-adjustment
    There’s a reasonable explanation of the purpose of the limit screw. Beware though, as said above, setting them incorrectly can be expensive and painful.

  • Man needs no manuals. Seriously though, I fixed it already, and what an ordeal it was.
    Cable was too long and grabbing somewhere so I took all the thing apart and put it back together in a much cleaner route.
    Then I took the derailleur off. Fixed one pulley, cleaned and oiled, back in.
    All together now, worked a bit better but still the same problem, sometimes stuck on the big cog.
    Out of desperation, I just measured the chain length (Sheldon's way). Too long, chopped a few links, better. Then I chopped the rest, too short (!), derailleur was hanging too far off the cassette and shifting was awful.
    Finally, I got a chain of my spares. Almost perfect, adjusted it an now don't miss any shift. Still, I have the limit screw all the way out and there's still space between cassette and pulley, could do with 1 or 2 links more.

  • TL; DR fixed cabling, shortened chain.
    Not sure what the reasoning behind shorter chain making it easier to go down are... Mechanical advantage? Spring more extended?
    Mixed feelings about all this 1x shite, got a better 2x already, but can't use it just yet

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SRAM Apex 1 downshifting problems

Posted by Avatar for Netakure @Netakure

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