Am I a Power-God or did I do something wrong???

[Steve H]

My chain was wearing quite a bit, so time for a replacement. I thought it would also be sensible to change the cassette this time around. I'm not that great at maintenance, but these are jobs I can do and have the tools for.

So off comes the wheel and out come the chain whip and the lock-ring tool. I get the lock-ring off reasonably easily and off comes the first couple of sprockets of the cassette with ease. However the next sprocket is a bit stuck. After a lot of jiggling, I have to apply pliers and the chain whip again. Same for the next couple of sprockets. It turns out that some of the sprockets have twisted into the freehub. Now this was a Shimano 105 cassette on a Shimano/SRAM freehub and I seem to recall that the cassette would only fit on when aligned the right way. See photo of how the cassette has twisted into the freehub.

So have I done something wrong when I fitted this cassette last time? Or do I simply have legs so strong that regular equipment isn't tough enough for me???

 

[oldfatfool]

I will go for fitted wrong (don't know how though, did you use a hammer? ) otherwise there would be groves at the same position on every spline of the freehub.

 

[02GF74]

that's amazing; i've never seen anything as bad as that - you can get small nicks on an alloy casseette but this is in a different league entirely. it is not possible to fit the sprockets onto the free hub in any other way than the correct way due to the assymetrical positon of the smaller spline, even with a bigg hammer you would strruggle.

are there no similar grooves on the other splines?

 

[Rob3rt]

WTF. Alloy freehub bodies often get notched, esp if the cassette is not torqued down correctly but that is just bonkers.

 

[Rohloff_Brompton_Rider]

Looks like the lock ring wasn't tightened enough, allowing the sprockets to move about individually. When the lock ring is tightened, the whole block acts as one and spreads the load across the soft alloy free hub. When not tightend enough, the load is transmitted thru the individual sprockets allowing the pressure to dig in. Think of a stiletto heel digging into a soft floor where wide shoes wouldn't.

Just file down the rough edges Steve, when you fit the new block, make sure you tighten the lock ring enough.

 

[lulubel]

Wouldn't the cassette wobble around and run noisily if the lock ring wasn't tightened enough?

 

[potsy]

Awesome power is my bet, downhill anyway

 

[Rohloff_Brompton_Rider]

Wouldn't the cassette wobble around and run noisily if the lock ring wasn't tightened enough?

Only if really lose, I mean it was tight, just not tight enough.

 

[lulubel]

Only if really lose, I mean it was tight, just not tight enough.

OK, thanks. I asked because I was told, as long as the cassette doesn't move laterally, it's tight enough.

That was obviously wrong, so I'd better tighten mine up!

 

[Rohloff_Brompton_Rider]

That's true, for cassettes that are on carrier bodies, not individual sprockets. Personally I'd have a steel free hub body with individual sprockets.

 

[accountantpete]

Theoretically the splines should spread the load and contact the sprocket all the way around

Yours only have notches on one raised part of the freehub - meaning that the other raised areas were not making contact with sprocket.

That is why the freehub has worn away so badly. I'd have a close look at the individual sprockets and try and work out what has gone on.

 

[Steve H]

Looks like the lock ring wasn't tightened enough, allowing the sprockets to move about individually. When the lock ring is tightened, the whole block acts as one and spreads the load across the soft alloy free hub. When not tightend enough, the load is transmitted thru the individual sprockets allowing the pressure to dig in. Think of a stiletto heel digging into a soft floor where wide shoes wouldn't.

Just file down the rough edges Steve, when you fit the new block, make sure you tighten the lock ring enough.

Thanks - sounds like a sensible explanation. The lock ring did seem to come loose much easier than when I've changed cassettes before. It says 40Nm on it, which is pretty tight, so if the sprockets can move individually when the torque isn't tight enough, that would explain the result.

So is the general consensus that I can still use this freehub if I tighten my next cassette sufficiently? Or am I safer replacing it? I don't want a situation where the middle gears suddenly cut through the freehub.

 

[Rohloff_Brompton_Rider]

Thanks - sounds like a sensible explanation. The lock ring did seem to come loose much easier than when I've changed cassettes before. It says 40Nm on it, which is pretty tight, so if the sprockets can move individually when the torque isn't tight enough, that would explain the result.

So is the general consensus that I can still use this freehub if I tighten my next cassette sufficiently? Or am I safer replacing it? I don't want a situation where the middle gears suddenly cut through the freehub.

nah you'll be fine Steve, it will need fettling so the sprockets will go on smoothly.

 

[lulubel]

That's true, for cassettes that are on carrier bodies, not individual sprockets. Personally I'd have a steel free hub body with individual sprockets.

This is why I love this forum. I've acquired more knowledge about bikes since I've been a member here than in my whole life "before CC".

 

[Rohloff_Brompton_Rider]

This is why I love this forum. I've acquired more knowledge about bikes since I've been a member here than in my whole life "before CC".

yep....fools learn by their mistakes....genius' learn off other peoples mistakes....

i'm no genius...