Slipping, little advice

Dfects

Hiya guys,

Hoping for a little advice I have an old GT Outpost I commute on sometimes that's unfortunately started slipping somewhere on the rear. It has Shimano deore XT hubs (m705) with a 7 speed shimano cassette (cs-hg30). It happens normally under pressure but not always and isn't consistent. The peddle gives way maybe 1-2 inches, loud "twang" and it generally results in pain and almost getting run over.

I've swapped the rear wheel from my other halfs bike and so far its been fine, so pretty sure its either the cassette or something in the hub

Any idea what the most likely culprit is? I'm trying to figure out whether its worth investing in the tools to take it apart and try to fix it (new bearing's, regrease, cassette), or to buy another cheap wheel/hub/cassette pre built. I only paid £70 for the bike a few years back so I don't want to sink too much into it.

I've taken a photo of the cassette here. It doesn't look to me like its particularly worn? Please excuse the filth :oops: I normally keep things pretty clean but it's been peeving me off

http://photos.nullabletype.co.uk/Site/nullabletypecouk/2811055_d7pSB5#!i=2554840685&k=QjjSTWp&lb=1&s=O

Any help appreciated! Thanks

thistle_

Check the length of your chain. 12 full links should be exactly 12", if it's more then your chain is probably worn out and needs replacing. If it's a lot more than 12" you probably need to replace the cassette too.
Google "chain stretch" and read the info on sheldonbrown.com about it.

Buying a cassette tool, chain whip and chain breaker shouldn't set you back more than £30 if you're on a tight budget and if you're using your bike a fair bit they will be worth the investment.

It could be the freehub or something else, but it's usually the chain/rear cassette.

SRAM PC971 chains were under £10 on Amazon the other day.

Dfects

Thanks for the reply

I did actually replace the chain, but it didn't help. I think when I first purchased the bike I also changed the chain as some of the links were a bit stiff... not sure if it was slipping from the moment I purchased as I didn't use it much until we moved closer to my work.

I'll invest in some tools, try swapping the cassette and give the hub a service too, hopefully that will sort it. Thanks!

The Rookie

New chain on a worn cassette is a perfect recipe for slip, it will often be worse than it was with the matching worn chain.

Dfects

I generally ride from 4-7 on the rear, I haven't noticed it only happening on one ring, it could easily be though!

I've ordered some bits now. As it had a HG cassette on before I've bought a hg41 cassette and the recommended hg40 chain so hopefully they'll match well and sort the problem out. I've also bought some new bearings and grease to do at the same time as I haven't done it before, and I have no idea if the previous owner did either!

leevil knievil

It could be the free hub, or chain jumping as has been said I would prob lean towards the free hub, pawls or teeth maybe worn had a similar thing on mine but it wasn't a shimano hub.

Dfects

Well if this doesn't sort it, I guess I can at least just buy a new wheel and hub to fit the cassette and chain. Really hoping it doesn't come to that though

Maro

Another vote for free hub, if a different wheel fixed it and a new chain didn't I would go for the hub.