Need fault finding advice
 

I've got a fairly new mountain bike (done approx 100 miles) but there is an intermittant clunk has developed when I peddle. Any ideas on the source of this problem?

can you be a littel more descriptive? does the clunk occur with each pedal stroke or wheel rotation?

Cheers for responding Todd - The clunk isn't strictly routine but intermittant. If it was routine I would suspect cogs or chain maybe. The clunk can be felt fairly often when cycling. A sort of grinding clunk. Please help.