Well I've had her a year now and 22,000 miles on the clock !
I don't know if you guys know it but the speedo/odo is optomistic by at least 5%.
That said,your mileage is a little lower than it looks.
I am running a car tire on mine now and it's a larger circle and much closer to ACTUAL mileage/odometer possibly an overdrive.
Babying her I get 42 -45 now.
It's probably a little more than that 'cause the speedo/odo doesn't know she's a little overgeared.
5,000 on the car tire so far !
JJ