Can't pedal forwards - sprocket is free-wheeling?

[Barefoot_Wanderer]

Hi All

I have an 8-speed mtb (Saracen Raw3) with a cassette sprocket. When I pedal forwards the sprocket free-wheels which means the bike doesn't go anywhere. If I get hold of the sprockets I can turn it both anti-clockwise and clockwise

I changed the cassette about 3 months ago but the bearings haven't been changed or greased since I bought it (2007) (maybe the problem?)

I can ride the bike for a short time before it happens - after a few moments the sprocket will grip again and then stop again and so on...

I've tried bringing the wheel inside the house thinking there might be frozen water inside the cassette but the problem persisted

I'm not a complete beginner when it come to fixing bikes but this is a new area for me and need some ideas before I take the cassete off (which I've done before when I rteplaced it) will I need to grease the bearings or even try spaying some lube/wd40 into the cassette?

Your thoughts appreciated

thanks in advance!

[1FJEF]

NO WD-40 unless you use it as a parts flush & degreaser! It's not a good lube, use a good lube after WD-40.
If you have an 8 speed you almost certainly have a cassette rather than a freewheel. The cassette fits onto your freehub. The freehub has the ratchet assembly in it, the cassette is not involved.
Your freehub is the issue, (unless you have somehow destroyed the splines which locate the cassette during installation) and needs to be replaced or lubed.
My hubs need the axle removed to get some lube in the freehub. Go look here. Remove the axle & bearings, get some thin oil like Tri Flow or Break Free for step 7.

[Barefoot_Wanderer]

(01-07-2014, 08:01 PM)1FJEF Wrote:  NO WD-40 unless you use it as a parts flush & degreaser! It's not a good lube, use a good lube after WD-40.
If you have an 8 speed you almost certainly have a cassette rather than a freewheel. The cassette fits onto your freehub. The freehub has the ratchet assembly in it, the cassette is not involved.
Your freehub is the issue, (unless you have somehow destroyed the splines which locate the cassette during installation) and needs to be replaced or lubed.
My hubs need the axle removed to get some lube in the freehub. Go look here. Remove the axle & bearings, get some thin oil like Tri Flow or Break Free for step 7.

Just what I was looking for.

Thanks for link and advice :-)

[Barefoot_Wanderer]

I've just been looking what I have available at moment - I already have a spray lube like this one - could I use this instead of the triflow?

I also have a household degreaser (Mr. Muscle) which I have used to wash the chain and sprockets - this could be used instead of the Citrus ChainBrite

Finally I have a box standard pot of grease I could use for the bearings? Should be OK?

I know I'm cheapskating a bit but I have these already. Let me know what you think

Cheers,

Andy

[1FJEF]

I'm not familiar with the product, but I am wary of a "lubricant" that claims water displacement (like WD-40) as a major feature.