Hi MF,

Thanks appreciate your kinds words - nothing that a coffee and a 'couple' of choc biscuits can't assist. :-/

Alas no, it's not just an adjustment factor. I have played with the amount of tension on the belt tension arm and on the smaller belts (M36) it literally cannot move at all and when tensioned up this doesn't change - so much so in trying this I literally snapped the steel cable - alas another minor thing now to fix.

On the bigger belts the amount of movement on the tension arm is I am certain correct - it almost fully comes out - but can't put enough extra grab on the belt.

I'm really befuddled by it as I've now tried 36, 37 and 38 - but no luck on any of them. Atleast one of each size came from a reputable maker and so I am sure there sizing technique is sound i.e referring to internal diameter as their size.

I'll duck down and get a few pictures, if nothing else they add context - I agree and felt that a relatively well known model would be simple to find a replacement belt for - but as this thread will show there seems to be much varying info.

Thanks again - this thread has felt a tad 'lonely' so atleast I know someone has seen it and perhaps we can get to the bottom of it in time. :-)