That prospect of my camshaft drive belts snapping is a chilling one. My VW 1.9 Turbo diesel engine has perhaps 2mm clearance between the closed valve and the piston at TDC. Belt snapped = new engine is the rule here in the UK. It causes terrible engine damage and a complete rebuild so they just scrap the whole engine. That cost £4000 when the exchange rate was E1.25 to £1. Now it would probably be £5000 if the belt broke. I replaced my camshaft drive belt at forty thousand miles and spent £300 in fees to the mechanic as preventive maintenance. Well worth it. I still don’t think the belt should have a hard life when used on a strida. Turning a car camshaft must be a far harder job I think. Probably similar torque to pushing the strida along, but much faster. I’d expect the strida drive belt to last a very long time if it had been handled properly.