P500 Tire size = indicated speed?

[Bushbaby]

I think this was discussed somewhere else on the site but I can't find it. So I've gone from a 24" OEM tire to a 26" Maxxus BH and I know my speedometer isn't reading correctly. I never was any good at math or even basic arithmetic so could someone please give me a number I could use to multiply the speedometer reading by to give me the correct speed. I was out for an end of season ride yesterday on a smooth forestry dirt road and I opened her up and it felt like we were flying. Speedometer indicated 55/60 kph the fastest I've ever had the 500. If a math genius could help me out it will be much appreciated. TIA

 

[Admin]

 

[Mudder]

?? Comments on 26 and 27s amd some other links in thread. Interesting how the speedometer seems more accurate with larger tires? Maybe one Honda engineer guessed right on how customers would mod their P500s.
P500 - Speedometer inaccurate?

 

[tomcj2]

Circumference is calculated by (pi x diameter)
3.1417 x 24 = 75.4 in (approximately)
3.1417 x 26 = 81.68in (approximately)

The circumference of your new tires is about 8% greater than your old ones. In other words when your speedometer reads 55 km/hr you will now be going 8% further and 8% faster than you you were going on your old tires.

My 2018 P500 with OE tires on it tops out at 64 km/hr before the computer limits it.

Before I posted this I took 'The Toy" out for a quick spin. When it registered 40 km/hr my GPS indicated 36 to 37 km/hr, which is about an 8% error. Your actual speed is probably very close to what the speedometer now reads with the larger tires on it.

Why is this the "end of season"? The snow is just about here and there are lots of hills in Elliot Lake. I live about 40 km from you; if I have to bundle up just to walk outside in the middle of winter I will probably just use my P500 to drive the few blocks to the store or mailbox rather than scrape and warm-up my car. I just installed a plow and will probably help some of my neighbours after the big snow dumps.

 

[Bushbaby]

Circumference is calculated by (pi x diameter)
3.1417 x 24 = 75.4 in (approximately)
3.1417 x 26 = 81.68in (approximately)

The circumference of your new tires is about 8% greater than your old ones. In other words when your speedometer reads 55 km/hr you will now be going 8% further and 8% faster than you you were going on your old tires.

My 2018 P500 with OE tires on it tops out at 64 km/hr before the computer limits it.

Before I posted this I took 'The Toy" out for a quick spin. When it registered 40 km/hr my GPS indicated 36 to 37 km/hr, which is about an 8% error. Your actual speed is probably very close to what the speedometer now reads with the larger tires on it.

Why is this the "end of season"? The snow is just about here and there are lots of hills in Elliot Lake. I live about 40 km from you; if I have to bundle up just to walk outside in the middle of winter I will probably just use my P500 to drive the few blocks to the store or mailbox rather than scrape and warm-up my car. I just installed a plow and will probably help some of my neighbours after the big snow dumps.

With all the extras I've put on the 500 the last thing I would have thought of are downhill skis! RFLMAO.
Thanks Tom - great info.

 

[Chooglin]

Why not just use a gps ?

 

[Bushbaby]

Why not just use a gps ?

Thanks Chooglin that's what I'll try next spring. Right now the 500 is on the trailer, covered, fuel stabiliser added and run into the carb yesterday, oil changed and the battery brought indoors. Now I have to do my 14ft. Lund aluminum boat that I tow behind my 500 for those hard to get to favorite fishing holes.

 

[trigger]

Doing all that math still won't make it go any faster.

 

[tomcj2]

Doing all that math still won't make it go any faster.

The metric system has some benefits. I weigh 102 and my P500 goes 64. My twin brother in the USA scales in at 225 and his machine only goes 40.