Another wobbly freewheel cluster

[AlexM]

My cheapish bike has a noticeable wobble in the freewheel cluster. Easy to see when the rear wheel free-spins and you look down at the cluster. I'm sure it's not a bent axle because the wheel is tree and doesn't wobble at all. Also, almost every bike I've got has some wobble in the cluster. Seems endemic and I'm just curious as to why. People rarely have cause to open up clusters but generally they have gaps in the number of bearings used ie there might 30 odd little ball bearings in a race but room for 40. Given that there's an outer and inner race in the clusters, I'm wondering whether this contributes to the wobble, allowing a little bit of lateral movement mechanism turns.

Wheel bearings, cups and cones all in good shape.
I'm going to try packing a few more bearings in the races with maybe only a 2-3 bearing space left.

This previous post from someone else shows the exact problem with video footage, but I don't think any of the replies get to the cause.
Anyone got any other theories?

[Painkiller]

it could be just a cheap cluster, If the bike is not throwing the chain and is shifting good do not worry about it. Also if the cogs on the cluster become loose because the rivets fatigue that will cause the problem you describe

[nfmisso]

(05-21-2011, 08:44 PM)AlexM Wrote:  ........
Wheel bearings, cups and cones all in good shape.
I'm going to try packing a few more bearings in the races with maybe only a 2-3 bearing space left.
.......

if you are using loose balls, fill it up so that there is not enough room for even one additional ball. There will still be a slight gap; like a half a ball or so.

[AlexM]

Filled it up with bearings, no loose rivets or play in the bearings. She just wants to wobble. Gear changing is not good - ie adjust the high range and the low range end goes askew; and vice versa.
I think it's a buddhist thing ... sometimes you just have let things wobble.

Have a look at the video on this post ... it's the exact same problem.

http://forums.bikeride.com/thread-1438.html

You'll see that the wheel's pretty true, but the cluster is just wobbling a bit.
My other bike. My partner's bike and every other spare mongrel bike I've had does this to some degree, though the current one is quite pronounced.
Check your own bike. Just lift the back wheel and spin it freely so the cluster freewheels and stays stationery, and look down at the cluster. I think in the northern hemisphere it will wobble in the other direction though!
Here's my knew theory ... this is actually a built in engineering feature that help promote gear change?! No?
Cheers
a

[trevgbb]

Cheap bikes use cheap components, these are made to much wider tolerances than quality parts, at one time there were several very thin packing washers below the lock ring which enabled the bearing preload to be adjusted, don't know if they still fit these as life is too short to dismantle a freewheel.

[SpennyCycles]

Just to add a comment on wobbly screw on freewheels. I just had a bike in for a PDI as they didn't want to go back to the shop. The freewheel was wobbling massively, (wheel itself was perfectly true) - at least 5mm of movement and the chain was grazing the wheel protector in bottom gear. Took the wheel off, the axle was off centre making inserting the freewheel remover tool very difficult. Once undone it was clear that it was cross-threaded. Fortunately, it replaced ok so no trashed wheel or freewheel.

Sometimes there is a simple reason for a problem.