I have a Giant Escape, with Shimano Acera gears (3 speed on the front, 7 speeds on the back). When the chain is in the hardest gear on the front cassette, then it is reluctant to shift into the hardest gear on the back cassette, otherwise it works fine.

When shifting from 6th to 7th, it stays in 6th while making a rattling sound for anywhere from 1 second to a minute, before changing to 7th.

I've tried decreasing the gear chain tension until it is basically slack when in 6th, but this doesn't help. I also don't think it is the limit screws (it was working fine before) and it shifts fine when not in the hardest gear on the front.

Also, this started when I had the rear wheel replaced 1 month ago.


This only seems to happen when I'm riding the bike, when it is stationary and I am pedalling by hand, everything works fine, for some reason. Also, I've tried replacing both the inner and outer gear cable.

  • 1
    How is the cable tension when you're trying to go to big-front and small-rear cog? Is it so loose that its dangling with slack?
    – Criggie
    Jan 6, 2016 at 21:44
  • @Criggie It's dangling just a bit, there's very little tension
    – texasflood
    Jan 6, 2016 at 21:48
  • 1
    when you replaced the wheel, did you replace the cassette, or did you keep the old one and use it on the new one? It could also be a bent derailleur hanger which is common, and i believe for your bike, replaceable. images would be helpful.
    – BrianC
    Jan 6, 2016 at 22:23
  • 1
    have you tried adjusting the limit screw? It'd not uncommon if you do something like changing a wheel, that distances can change slightly. Also frames can flex under load, which might explain why you don't see anything when the bike is in a stand
    – PeteH
    Jan 6, 2016 at 22:32
  • 4
    It sure sounds like the limit screws need tweaking. The other slight possibility is that the axle/hub is flexing slightly under load, which may be what Frisbee is thinking. Jan 7, 2016 at 3:16

1 Answer 1


It was in fact the H limit screw.

  • Good work - thank you for the closure. You can click the big tick/check on the left (below the up/down vote buttons) to confirm this is the accepted answer.
    – Criggie
    Jan 9, 2016 at 0:49

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