got a couple Kenda 270's for the rear and a Kenda 777 for the front. gotta be better than the stockers. review later...
I love mine on the 510. Little bit soft in the sidewall but not bad at all in the bush. Very close to running a "Trials Tire".
front is WAY better in the sand the rear will not last if I keep spinning up on gravel but I'm very pleased with the traction even in sand it seems to grip
I've run Kendas on a lot bikes and always found them to be as good or better than a lot of the priceier competition.