Last summer it come to light that my bike is suffering extremely bad chain slip, to the extent I feel it is unsafe. From what I can tell, it only happens in the 50t ring, and the 34 may be ok, but it's been a while since I've been on this particular bike, so I'd have to verify.

Near come off the bike a few times moving off from a stop if I was pedalling out of the saddle, so I got a chain checker and I noticed that it was badly worn; the tool slipped right into 1% and who knows how long it was like that given my attitude to use things until they break. Maybe 10-15k miles on the chain. It didn't fix it. So I installed new cassette on there 100-200 miles later, and again, it unfortunately, didn't fix it.

I've reassessed the chain length, and this seems O.K. from what I can gauge (big-big combo - chain has good tension, and I'm not quite able to turn 2 links back on each other to make a Z, indicating that the chain is probably the right length), so now I've reached somewhat of a brick wall. I can't keep throwing money at the thing, especially considering my next step would be to replace the large chainring, but given the cost of FC-9000, it would be quite annoying if it were not to work. Is this a likely fix?

A friend suggested sticky pawls, but when I shoved a club mates disc wheel & cassette on there, I had the same thing, so that probably rules out the possibility of the freehub assembly going bad.

If there is anyone out there with ideas/advice then it would be greatly appreciated. I can get high-resolution photos of the teeth/drivetrain condition if it helps.

EDIT; just shoved it in the workstand and noticed the rear gears were very hesitant to go 25>28 in the big ring & adjusted accordingly. I could've sworn I indexed the thing when I last used it though. If that is the case could this add new cables and a blob of marine grease to the RD springs to the list of culprits?

Last summer it come to light that my bike is suffering extremely bad chain slip, to the extent I feel it is unsafe. From what I can tell, it only happens in the 50t ring, and the 34 may be ok, but it's been a while since I've been on this particular bike, so I'd have to verify.

Near come off the bike a few times moving off from a stop if I was pedalling out of the saddle, so I got a chain checker and I noticed that it was badly worn; the tool slipped right into 1% and who knows how long it was like that given my attitude to use things until they break. Maybe 10-15k miles on the chain. It didn't fix it. So I installed new cassette on there 100-200 miles later, and again, it unfortunately, didn't fix it.

I've reassessed the chain length, and this seems O.K. from what I can gauge (big-big combo - chain has good tension, and I'm not quite able to turn 2 links back on each other to make a Z, indicating that the chain is probably the right length), so now I've reached somewhat of a brick wall. I can't keep throwing money at the thing, especially considering my next step would be to replace the large chainring, but given the cost of FC-9000, it would be quite annoying if it were not to work. Is this a likely fix?

A friend suggested sticky pawls, but when I shoved a club mates disc wheel & cassette on there, I had the same thing, so that probably rules out the possibility of the freehub assembly going bad.

If there is anyone out there with ideas/advice then it would be greatly appreciated. I can get high-resolution photos of the teeth/drivetrain condition if it helps.

EDIT; just shoved it in the workstand and noticed the rear gears were very hesitant to go 25>28 in the big ring & adjusted accordingly. I could've sworn I indexed the thing when I last used it though. If that is the case could this add new cables and a blob of marine grease to the RD springs to the list of culprits?

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Last summer it come to light that my bike is suffering extremely bad chain slip, to the extent I feel it is unsafe. From what I can tell, it only happens in the 50t ring, and the 34 may be ok, but it's been a while since I've been on this particular bike, so I'd have to verify.

Near come off the bike a few times moving off from a stop if I was pedalling out of the saddle, so I got a chain checker and I noticed that it was badly worn; the tool slipped right into 1% and who knows how long it was like that given my attitude to use things until they break. Maybe 10-15k miles on the chain. It didn't fix it. So I installed new cassette on there 100-200 miles later, and again, it unfortunately, didn't fix it.

I've reassessed the chain length, and this seems O.K. from what I can gauge (big-big combo - chain has good tension, and I'm not quite able to turn 2 links back on each other to make a Z, indicating that the chain is probably the right length), so now I've reached somewhat of a brick wall. I can't keep throwing money at the thing, especially considering my next step would be to replace the large chainring, but given the cost of FC-9000, it would be quite annoying if it were not to work. Is this a likely fix?

A friend suggested sticky pawls, but when I shoved a club mates disc wheel & cassette on there, I had the same thing, so that probably rules out the possibility of the freehub assembly going bad.

If there is anyone out there with ideas/advice then it would be greatly appreciated. I can get high-resolution photos of the teeth/drivetrain condition if it helps.

Last summer it come to light that my bike is suffering extremely bad chain slip, to the extent I feel it is unsafe. From what I can tell, it only happens in the 50t ring, and the 34 may be ok, but it's been a while since I've been on this particular bike, so I'd have to verify.

Near come off the bike a few times moving off from a stop if I was pedalling out of the saddle, so I got a chain checker and I noticed that it was badly worn; the tool slipped right into 1% and who knows how long it was like that given my attitude to use things until they break. Maybe 10-15k miles on the chain. It didn't fix it. So I installed new cassette on there 100-200 miles later, and again, it unfortunately, didn't fix it.

I've reassessed the chain length, and this seems O.K. from what I can gauge (big-big combo - chain has good tension, and I'm not quite able to turn 2 links back on each other to make a Z, indicating that the chain is probably the right length), so now I've reached somewhat of a brick wall. I can't keep throwing money at the thing, especially considering my next step would be to replace the large chainring, but given the cost of FC-9000, it would be quite annoying if it were not to work. Is this a likely fix?

A friend suggested sticky pawls, but when I shoved a club mates disc wheel & cassette on there, I had the same thing, so that probably rules out the possibility of the freehub assembly going bad.

If there is anyone out there with ideas/advice then it would be greatly appreciated. I can get high-resolution photos of the teeth/drivetrain condition if it helps.

EDIT; just shoved it in the workstand and noticed the rear gears were very hesitant to go 25>28 in the big ring & adjusted accordingly. I could've sworn I indexed the thing when I last used it though. If that is the case could this add new cables and a blob of marine grease to the RD springs to the list of culprits?