In reply to Jim C:
> (In reply to DreadyCraig)
> I would be tempted ,initially at least, to just to bolt down a 7' tapered hardwood 'doorstep' about 3" or 4" wide starting at say 1/4" or 1/2" thick on end and 2-1/4" to 2-1/2" thick
Been thinking of something similar in my garage - the floor is anything but level
It slopes slightly towards the door and noticeably from left to right, such that there is a gap of nearly 2 inches under one side of the door.
Unfortunately, any sort of lip there will be a pain to get the motorbike over and a bit of a trip hazard.