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Question about bicycle cassette Answered


I bought an Shimano HG-50 8 speed cassette.

When fitted, I could see that it did not seem to be exactly true.

For example, if I turn it backwards with my fingers and use a spoke as a reference point, it deviates by at least 1mm

I took everything apart and tightened up the free-hub.

The free-hub run perfectly true.

It was still the same when reassembled.

So I sent off for another HG-50 ( intending to send the defective one back).

The newest HG-50 was the same.

When I try I put on another new cassette ( an HG model but very old stock) it runs true ( it is a 7 speed with a spacer).

Does anyone have any helpful input.

Thank you


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1 year ago

I think it would not make any difference to how your bike will preform. You would not normally spin the pedal backward, any runout would be taken up by the derailleur, if its a mountain bike you would get more runout than that as soon as the chain gets loaded with mud and crap.


Reply 1 year ago


Yeah, it seems to run ok.



1 year ago

Most of these things are not fully horizontal to the axis.
I only had a few bikes without a "wobble" in the cassette.
But sometimes you can just be fooled by this wobble and seemingly misaligned and faulty part.
Try this:
Assemble all properly.
Spin the pedals and keep a slight resistance on the wheel.
Take a pin, pen, stick or whatever you have to check for the wobble now.
You might need a second person if you don't have a suitable stand and set the brakes.
In most caes there won't be any wobbl anymore.
For a good cassette this "wobble" is actually intended.
It makes sure that, under load, the gears align properly with the chain.
Keep in mind: The angle of your chain changes with the gears and the cassette has to compensate for this as otherwise the chain would wear out quickly ;)