I ask as I have an idea to use moped wheels at the front of a tadpole trike. They effectively have a "fat" tyre at 110mm wide which will combine nicely with the old Kawasaki 1000cc rear and swing arm I possess for the rear. The 'ped wheels are only 12" (that's a proper 12" for the wheel only not the cycle way of measuring including the tyre) and stand about 16.5" in total. They cost very little indeed on ebay, coming in at sub £50 for a pair of wheels, tyres and discs. The calipers will possibly require widening to cope - not expecting an issue there. The issue is the bearings accommodate a M12 bolt. I'm certain a 3/8 isn't butch enough and I know a 14mm will cope even with a porker such as myself. I'm taking a bit of a gamble here in trusting a M12 but should I get high tensile bolts or not? Are the 14mm axles high tensile? It seems that I ought to copy the tensile rating of the 14mm axles. Equally I'd rather have a failure of a bent axle than a snapped one. All advice, speculation or "that's a bad idea because"'s welcome.