I would venture that no it shouldnt.

what part broke?

I'm not familiar with the technical term but I would describe it as the 'side-bit that the left side crank arm slides onto'.

if the spindle went (which is what it sounds like you're saying) then I doubt the bike shop had much to do with the failure

So are we talking more of a manufacturing fault?

Nothing to do with fitting in my opinion. Either manufacturing fault, or you weigh 25 stone.

However if the lbs supplied and fitted then yes, they should sort it out even though not actually there 'fault' if it's a decent shop it should be no problem.

What kind of BB is it? Square taper? Hollowtech? Unless you were doing some serious "stunt riding" it sounds like a manufacturing defect. In any case, the bearings on a BB ought to wear out long before the axle snaps.

Errm - if they supplied and fitted it then they must replace it.

I'm a big bloke but not a whale so wouldn't put it down to 'physiological reasons' on this occasion. Am hoping that a sensisble and not too costly solution can be found (considering transapp's point). Will feedback once LBS have had a look at it and given their views (can't take it in till next week - gutted as I was doing the London transport cycle challenge (I live in Hertfordshire and XC into Enfield) and had been racking up the miles).

Incidentally can anyone recommend reliable cheapish trip computer? Recently bought a £30 cateye that's proved to be bunk - even with replacement battery (having a bad run of luck as you may tell).

Have a look at the VDO range. I've got an A8+ and it's been going strong for a few years now.

Thanks for the tip tuckerUK I'll check the vdo out. Bit miffed I wasted £30 though. I hope it goes well with the LBS because they've always seemed like nice guys and the mechanic has sorted me out in the past on a brake overhaul. I'm off to afan/brechfa in a couple of weeks and need a few more bits and bobs so hopefully a good deal can be done.

Jimification - not au-fait with different bb types so couldn't say (mental note to self: 'male more time to learn more about my bike')

has the BB snapped/ failed or the crank?
I doubt either is the shops fault but they would deal with BB and ignore the crank as not their fault.. LBS fits tyre and then the wheel breaks would they fix the wheel?
Hollowtech has an external bottom bracket where you can see cups with notches on the outside.
Square taper has something square sticking out the Bottom bracket that the crank insert on to with a bolt on each side
Hollowtech is also hollow viewed from drive side [ right] with a plastic cap on the non drive side [left] - right and left as sat on the bike

Clarification - 'MAKE more time......' (****in' iPhone)

Junkyard - Ironically the same LBS sold me the left crank arm recently due to a stripped thread from a knackered cheap pedal (bought pricey new pedals off them too). The crank arm was sold to me at a discount as it was an 'as new' one that had been swapped out for a customer who upgraded the crankset when buying a new bike from them.