without me touching the gear levers - ok until I start uphill then it jumps up and down a gear every few revolutions of the pedals?

Sounds like the gears need adjusting. Check the sprokets as well to be sure they aren't missing any teeth or that they are bent

[Edited by Saxo Boy - 12/3/2003 1:57:56 PM]

Either that or:

Worn chainrings
Worn cassette (sp?)
Worn chain

But as SB says they could just need some adjustment. Do the gears change smoothly and quickly when you do want them to?

needs a good service.

bike has only been used 4 times

your shouting BOO and scaring it. ;)

What groupset are you running? Shimano stuff (even at the base level) should be fine, but there's some right dodgy stuff out there.

More likely it's due to the fact that it's new, the cables have stretched, and you now need to make some small adjustments. Check your manual, should tell you how to do it (though it's pretty intuitive tbh).

<thread hijack>
just bought a beautifulroad bike last night. Specialized Allez Comp frame, built up with '02 Ultegra, Rolf wheels, Campagnolo BB, carbon forks ...... make even my slick-shod MTBs seem like slugs on the road.
</thread hiajck>

One of my bikes used to do this, and it drove me bat****!:(:

One day, while cleaning the chain, I was turning the cranks backwards, and noticed that it jumped every so often.

A more careful look found a tight link in the chain.........this meant it stuck up, and tried to change gear.
I cured it with a chain tool, but if you find one, you can cure all but the worst by flexing the chain strongly to each side, against the tight link, until it frees off.

I've found several others on other peoples' bikes too, so it's not that rare.

Alcazar

Hate to say "I told you so" but... I did try to warn you that Claude Butler MTBs (and cheapo MTBs in general) are rubbish, with cheap componants. Surely the place you bought it will sort it out for you f.o.c.? Personally I would try to get shot of it. Sorry.

UB:(

Sounds like 'ghost shifting' - caused by suspension action pulling on the cable (if it's a full suss bike) or just slight lack of fine adjustment. You could try an Avid Rollamajig - Chain Reaction Cycles sell them. Just a little roller that takes away the big curve of cable outer that goes to the rear mech.