Rear wheel/cassette

apple eater

My back wheel has started making a rotating click/grinding noise.

If i spin the wheel backwards it makes the noise and rolling forward it makes the noise. The bearings and axle are new and fine with no play in the axle. I took the wheel off tonight and discovered the noise is coming from the cassette when that spins.

Anyone know what this is? grit or worn bearings? are cassettes sealed units and need to be replaced as such?

The cassette is a shimano hyperglide-c 7 speed on a shimano fhm475 hub.

sniper68

It's more than likely the freehub.Cassettes sit on the freehub,if it's making the noise when pedalling and freewheeling then that's your problem.Inside the freehub are Pawls.Pawls are what allows the wheel to "freewheel" but lock the cassette to enable pedalling.The Pawls are quite flimsy on some cassettes so if any water/crud is in there then they could be grinding.
What hub is it?
Some freehubs can be rebuilt others can't.

apple eater

Shimano fhm 475 32 hole hub

sniper68

Looking at this:
http://techdocs.shimano.com/media/techd ... 728374.pdf
It's a sealed unit (Number 13 free hub body)part number Y-3SL98030
Shouldn't be more than a tenner,the complete hub is £26.Your LBS should be able to get a freehub.If you buy a complete hub you'll then have to have it laced into your rim so £26+spokes+wheel build+about £60 so a tenner on a freehub is your best bet.
All this is assuming it IS your freehub and you can do it yourself?

apple eater

I could change it myself, i'll need to buy the cassette removal tool and any other specific tool if needed. Thanks for the info.

I have a question though, i bought the bike used from someone who modified it.

The gear selector has 1 through 8 on it, the hub is described as an 8 - 9 speed hub but the cassette is a 7 speed?

Why would anyone down size from 8 to 7 speed?

supersonic

Must have got it cheap. They fit on the freehub with a 4.5mm spacer first.

You could upgrade to an 8 speed cassette easily.

http://www.jejamescycles.co.uk/shimano- ... 86752.html

apple eater

anyone want to recommend a hub upgrade? budget for the hub would be £50 - £60 max.

Chunkers1980

Yes the one above.

apple eater

either i'm missing something or the one above is the one i already have.

supersonic

A new hub would require unbuilding the wheel, new spokes, rebuild - be easier to get a new wheel.

Or just replace the freehub.

386ka

Either upgrade the hub, or buy the same hub, then swap the freehub from the new hub to the old hub. Then you are left with hub spares (axle, cones, bearings) for further servicing.