The BB on my Stumpy sounds like an asthmatic cement mixer, so it’s time to replace the bearings. However, looking at the cranks the recommended torque is something like 450lb and those mechanics at Specialized seem to have used every single one of those torques on my cranks, for the buggers won’t shift even when leaning my body on a breaker bar whilst holding both cranks with my hands.

I’m not a small bloke either.

Do I need to loosen the plastic collar on the axle first, or is it an LBS job?

AFAIK (seen a few I think) it’s a 10mm or 8mm in the self extracting nut then bounce on it.

Yep, 8mm allen key with a breaker bar…believe me, I bounced.

My Enduro’s cranks weren’t too tight but you do need to turn the bolt the right way!

I had to use an old handlebar to get mine undone. If it’s the same as mine the bolt is on the drive side and therefore undoes anti-clockwise as you’d expect. When undoing really tight bolts like these it helps to apply intermittent pressure i.e. apply – release, apply – release etc. This seems more effective at freeing the bolt than applying just a single load of constant pressure. Also position the pedal on the drive side so that it’s in the 3 O’Clock position. As you apply pressure to the bolt the pedal will rise, you can then put all your weight on the pedal/crank to stop it from moving. Cable tie the brakes levers closed as well for added security.