Originally Posted by
yippee
A few weeks ago my smallest cog started slipping and 2 bike shops told me my chain had stretched.
Did they say *how* they knew it had "stretched"? If you know (or believe) that they measured the chain elongation, then you need a new chain. If you think they just winged it, you could check the chain elongation yourself (which, IMO, you should be doing anyway... chain check tools are cheap and easy to use).
Steve