Shimano MF TZ 20 rear sprockets

[R0ckerB0nz0]

Hello members,

Can anybody help me with this query,I have have had two 6 speed hybrid bikes.One from Argos and the other from a cycle shop near me.The one from Argos was a 26inch wheel and the other is 28inch model.What my query is they all had the Shimano MFTz 20 cluster on the rear wheel and when i had to put repair punctures on the wheel i noticed that when you spin the wheel when the bike is upside down,the cluster has an eccentric wobble.Not shaking but like all the hubs are machined badly from new.I had to replace the wheel on the 26inch bike after an accident and that cluster has a uneven movement from side to side.My neighbour has Shimano gears and clusters on his 28inch wheel, 24 speed hybrid but that does not move like mine.
Has anybody else noticed this problem,it doesn't affect the bike when riding.

Thank you

Paul Brown.

[Brucey]

what you describe sounds like the hub itself is distorted, rather than just the freewheel. If the hubs are steel ones made of several parts pressed together, and have seen a bit of action, this kind of thing isn't uncommon. Occasionally it precedes a major internal hub problem.

cheers

[R0ckerB0nz0]

Hello Brucey, I have had 3 all the same types brand new with the same problem,they must have a manufacturing problem at Shimano factory.As i said before my neighbours bike hasn't got the problem which his bike is years old and had it.my old Townsend Rally Sport 10 speed racer which is years old which has Shimano gears but i have not the model type of the gears at the moment does the same as my 2 hybrids.
Talking of the Rally Sport, I am trying to find the replacement clevis pin shaft type shaft and double sprocket for the front.Might have to replace it with the modern type for that bike which i was trying to keep it original style.

Paul Brown.

[Brucey]

I have had 3 all the same types brand new with the same problem,they must have a manufacturing problem at Shimano factory..

not if the hub is defective; the freewheels could all be perfect and they will never run true when the wheel spins.

Note also that HG sprockets have chamfers near the top; these go one way for about half a turn and the other way for the other half a turn. At a glance freewheels like this can appear to be out of true, but it is an optical illusion in this case.

cheers

[AndyA]

Most cheap freewheels do this. The sprockets will wear out long before the rest of the freewheel fails in my experience so don't worry about it. Much more likely to snap or bend an axle than for the freewheel to fail. Part of me says buy a better rear wheel with a freehub rather than a freewheel because freehubs don't bend/break axles, but you'd likely be better off upgrading the whole bike.

On your Townsend I think the bit you're after is a cotter-pin rather than clevis-pin. You can still get em in 3/8" and 9mm (English and Continental) sizes