slipping

Quoted message said:

I have a CCM MegaSize mountain bike, it's at least 5 years old, and just a
few weeks ago the crank started slipping from the chainwheels, it would get
really ba (so bad i couldn't make it up sligh inclines), if i pedalled fast
while it was slipping then let it rest for about half a min it would stop
slipping. What i want to know is, why is it slipping, and what can i do
about it?

How many miles and what sort of maintenance has the chain had? How badly
worn is it presently? Your symptoms sound like what you get with a
*severely* worn (lengthened) chain, which tries to wear the chainrings &
rear cogs into its worn shape, eventually destroying them. Once
sufficiently bad, a new chain won't help things (and might even make it
worse). In that event, you need to replace chain, chainrings and rear cogs.

If you're not sure what's going on, bring it to your local bike shop. This
is the sort of thing that ought to be pretty easily diagnosed.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com