The front tyres on the five speeder are, I think, the same as I'm running on my vintage trike. Whilst I could understand a bit more wear as it's more powerful, 4200 km and looking worn out is suggestive of a lot of scrub, which you really don't want as it will reduce the overall adhesion. And as said before, a gross tracking error is the simplest way of getting this. Too much too toe in probably, since with too much toe out, the trike will be very nervous and dart this way and that at the slightest provocation.
Now a short life from the back tyre, that I could understand, You Tube is full of folk making oodles of smoke.
