tires size to change mph?
 

I have a Honda VTX 1300R MotorTrike. The speedometer reads 5 mph to fast at 60 on the speedometer, I'm only going 55 by my GPS. I want to put on norrower wheels on the same rims, and if I get taller ? wheels will that put me closer to the correct speed without loosing mpg. Any help would be appreciated.

Hi GeoDenny,

I had to do a google search to see what your trike looks like. I am not qualified to advise you but you might have more luck asking this question at a VTX1300 trike enthusiast site like:

Honda VTX Forum | VTX 1300 & 1800

That said, I see the stock rear trike tires are 205/R70-15. Your speedo reads approx. 10% fast. All you need is a higher profile tire on your current size rims to lower the speedometer readout back closer to accurate. The only problem I see is the rear fender clearance. Not sure how hard it is to raise the fenders to keep a higher profile tire from rubbing . Might make the trike look a little goofy though.

Best luck,
John Downs

That's How They Work
 

There's nothing wrong with your speedo that's just the way they are set up. It must legally read -2.5 mph and its bottom tolerance is -10% of indicated reading. So at an indicated 50 mph you are actually traveling at between 45 and 47.5 mph.

Yes, all bikes read 10% high and all cars read 5%+ high.

Best option is to fit a speedo-healer (or speedo-DRD) if you are really concerened about it.