Freewheel & Hub

Wirral

Hi, First post.!!

I hope this is a simple question.
I have broke the back axle (badly bent) on a freewheel / hub set up but I have been told that to repair its a complete new wheel & Chain!. Can anyone answer why can the axle alone not be replaced? WHy the whole thing?

Also can anyone explain exactly why the Cassette set up is stronger?

thanks
David

will3

Hi, you should be able to replace an axle. I've done it on many old wheels.

nyanza

You need a new bike shop; not a new wheel and chain.

Replacing an axle is simple and cheap enough. In the process of breaking it you may have damaged the hub internals such as the bearing cups, in which case a new hub is needed, but the existing rim and spokes are unlikely to be badly damaged and could be re-fitted around it. However, if it's just a cheap rim then an entirely new wheel fitted with a freewheel hub (ie you screw on the freewheel sprockets) is probably easiest and is only 25 quid in my LBS. You can then re-fit the freewheel cluster from your old wheel.

But a new chain? What?? Where'd that come from?

Freehubs (on which the cassette sits) are better than freewheels as the freehub supports the axle nearer the ends, so it is less likely to bend (which is what you have nicely demonstrated with your freewheel!)
Sheldon Brown explains with a pretty picture:
http://www.sheldonbrown.com/k7.html

Cranks

These comments all depend on the state of the overall wheel, freewheel and chain. We cannot see this so cannot comment on the bike shop's recommendation.

If you are running a freewheel, it can indicate 2 things at least, 1 being the wheel maybe old, or, 2, the wheel is of the cheaper spectrum. Both would suggest a bike shop would recommend a replacement rather than a fix (if it can be fixed).

Did they indicate reasons for replacing parts? What were they?

A second opinion will do you no harm if not happy.

Wirral

The bike shop recommend the same wheel standard but one with a freehub, a new cassette instead of the freewheel. Reason: the Freehub and cassette being strong so in the long run it will be stronger. However I figured that as my bike is a shit cheapo that surely its easier to replace the axle, more work but a damn sight cheaper.

The wheel is cheap same as the bike.
Age about 6 months old.

MichaelW

So you have a screw-on freewheel with a bent axle.
The bike shop wants to upgrade you to a stronger freehub requiring a new wheel.

If your existing freewheel is in good shape and not worn, all you need do is change the axle.
Cheap axles are not very good. Get a chromoly steel one.

You need to remove the freewheel to get to the cones. The easiest way is with a freewheel tool (a large nut with some splines on; several spline patterns available) and a bench vice. Dont bother with a chain-whip or large wrench.

Wirral

thanks for the answers.

Final question. Is there a way to understand the size/dimensions of the axle without removing it from the hub?