Bent Frame?

ed1973

Well I’m still stuck with a slipping chain that only slips in 13t gear.
I’ve tried lots of suggestions and my own thoughts:
Indexed gears done
Bought new rear hanger and attached
Aligned rear hanger (LBS did this)
Checked chain for length and sticky link
Replaced the 13t cog
Replaced the cassette
Changed the rear mech

I’m stuck now on what to do the only thing left is could a misaligned frame be the cause.
Any other suggestions?

whyamihere

The hanger alignment (if done properly) aligns the hanger to the wheel, so would accommodate a misaligned frame. The one thing you don't say you've replaced is the chain... Have you done that?

ed1973

whyamihere wrote:

The hanger alignment (if done properly) aligns the hanger to the wheel, so would accommodate a misaligned frame. The one thing you don't say you've replaced is the chain... Have you done that?

I’ve not replaced it, just checked it, even the mechanic at LBS said it was not stretched. Could this be the culprit? Would it slip on just 1 particular gear if it was needing replacing? It’s only done about 300miles.

ed1973

Another thing I have thought. The chain is a sram chain on a shimano cassette, would this make a difference?

cooldad

Nope.

bondurant

Bent derailleur?

Edit...missed that you've done that.

steve_sordy

Ref the chain: If its the only thing left, why not change it? If the problem remains the same, then you will have ruled that out too. And you could still put back the old chain and keep the new one for next time.

ed1973

steve_sordy wrote:

Ref the chain: If its the only thing left, why not change it? If the problem remains the same, then you will have ruled that out too. And you could still put back the old chain and keep the new one for next time.

Good idea, I’ll give it a bash, thanks for the advice.

steve_sordy

Something else occurred to m just as I was dropping off to sleep last night.

I note that you replaced the 13T cog. Was there any damage to the splines inside the cog? Has that damage been transferred to the freehub? If so, even a new 13T cog may slip on the damaged splines of the freehub. Unlikely I agree, but you have pretty much checked everything else.

What prompted that thought was that many years ago when I first got a bike with some gears (7 of them!), I had a similar problem that in one particular gear (can't remember which one now) used to slip when I put pressure on. It slipped with a huge clang and I nearly lost my footing on the pedals. The LBS changed the freehub and the job was done!

I just checked and you haven't mentioned the freehub as being changed so far. Could be a good place to look.

ed1973

steve_sordy wrote:

Something else occurred to m just as I was dropping off to sleep last night.

I note that you replaced the 13T cog. Was there any damage to the splines inside the cog? Has that damage been transferred to the freehub? If so, even a new 13T cog may slip on the damaged splines of the freehub. Unlikely I agree, but you have pretty much checked everything else.

What prompted that thought was that many years ago when I first got a bike with some gears (7 of them!), I had a similar problem that in one particular gear (can't remember which one now) used to slip when I put pressure on. It slipped with a huge clang and I nearly lost my footing on the pedals. The LBS changed the freehub and the job was done!

I just checked and you haven't mentioned the freehub as being changed so far. Could be a good place to look.

This is why I love this site, you guys are very helpful and think of stuff that doesn’t occur to me.
I will check the freehub for damage.
Once again thanks for all the helpful advice.
By the way, my best thinking always happens in the shower.

steve_sordy

Ed1973 wrote:

..........
By the way, my best thinking always happens in the shower.

We all know what men think with, so spend more time washing the rest of you!

ed1973

I’m pretty sure that you will all be excited to find out I’ve fixed my chain slipping issue. Having checked everything I (and you guys) could think of I went back to basics. Not only had I checked the chain but the lbs had checked the chain for wear and stretch and both were fine. Before forking out for a new chain that might not have solved the issue, I grabbed an older chain and put it in and wham, problem fixed. Big thanks to steve_sordy who hounded me to replace the chain.
In celebration of this mammoth solution. I have purchased a new cassette a new KMC (not shimano which was the route cause) chain and a new chainring!!

steve_sordy

An old chain running on a new cassette, or a new chain running on an old cassette are frequently a source of problems. So I'm not surprised that fitting an old chain back onto an old cassette solves the problem
But you had changed the cassette hadn't you quite recently? And the current chain had been checked and found OK?

I'm puzzled. It was only a really old chain that solved the problem, on your recent cassette?

I have no idea what the problem really was, maybe a duff cassette. Had you checked the teeth for burrs?

Anyway, I'm glad you got it sorted, but problem solving should not be just a policy of replacement until the problem goes away; so what have you learned from this?

ed1973

steve_sordy wrote:

An old chain running on a new cassette, or a new chain running on an old cassette are frequently a source of problems. So I'm not surprised that fitting an old chain back onto an old cassette solves the problem
But you had changed the cassette hadn't you quite recently? And the current chain had been checked and found OK?

I'm puzzled. It was only a really old chain that solved the problem, on your recent cassette?

I have no idea what the problem really was, maybe a duff cassette. Had you checked the teeth for burrs?

Anyway, I'm glad you got it sorted, but problem solving should not be just a policy of replacement until the problem goes away; so what have you learned from this?

Cassette and chain were originally bought and put on at the same time. Which is why I also found it odd!
Things I’ve learnt:
Listen to Steve
Don’t buy shimano chains

angry_bird

Changed the cables? I like blaming the cables, it's a good excuse to tinker with the bike a bit.