knee slider is your belt the same size as the 300i downtown 1004 mm. x 25.2 mm. with 30 degree I have bought 2 belts so far and they measure 1004 x 24 mm. so they are worn out brand new,. but they work very well,. and I have put 30,000 km. on the original belt and it still looks good, just a few cracks when you bend the belt tight, and it is still at 26 mm. , tops out at 144 km. per hour, I have not tryed down hill with a tail wind yet,. dressed to ride 230 lbs. 6 foot tall, and to old to do this often,. Don