"OFFER: CITYSPORTS walking treadmill, speed goes up to 6mph, machine needs some work. (Thetford)".
Ah, ok, 'needs some work'. This probably means that there is no speed control, we had one like that. You walk along and eventually end up running like hell trying to keep up with the machine. 6 mph is just a number you pass on the way to ????
I will pass on that offer. My DIY does not reach to that kind of stuff.