Just put on a bike speedo on my rancher and was wondering what tire cirrcumfance i should put into the display.

 

If you have the stock tires which are 24 inches in diameter than 3.14*24 = 75.36, therefore you cirrumference is 75.36. I did the same thing on my Rancher with a $20 bike speedo from walmart.

 

It has been a over a year since I did mine but I'll try to help. Put the atv on a flat surface and inflate tire to correct pressure. Measure from the top to the ground. I put a board across the top of the tire. If in inches : multiply the amount by 25.4 to convert into millimeters. Then multiply that number by 3.1416 and take that number and divide by 1.61 to get it back to english. You might have to select between km and mile on speedometer.
Depending on the speedometer, you might just have to multiply the height by 3.1416 and put that in
rounded to the highest or lowest number. (Measure the tire where the sensor is mounted.) On a 4x4 you can mount the magnet on a front drive axle. I used a flat round magnet from the bottom of an old shower curtain that I was throwing out. Silicone the magnet on. I know you said that you put it on. But I just want to point out to anyone else that might be interested in doing this. You'll probably have to splice
extra wire in to add length.

 

Hey, 'chaser, why does it matter to measure the circumference at the position where you put the magnet? It's only going to pass the pickup once every revolution no matter where on the wheel you put it, so the main thing is to get the overall circumference correct, right? Am I missing something here?

JC

 

Jerms,

You are correct in that it doesn't matter where on the wheel you place the magnet, because as you say "It's only going to pass the pickup once every revolution no matter where on the wheel you put it" is true. What's important is the size of the tire because the tire's overall diameter will determine how may times the wheel will spin in a mile, thus miles/hour. The smaller the tire size the more revolutions per mile and visa versa.

 

Right, my logic exactly. I was hoping I wasn't losing my mind...[img]i/expressions/face-icon-small-smile.gif[/img]
BTW, has anyone tried the Cateye Enduro 8 speedometer? You can see it at Cateye's site at http://www.cateye.com/detail_mod02.php?products_id=99. It sounds like it has some improvements over the Enduro 2 and you can get it for under $25 online. Their "Enduro" line supposedly is built a little more rugged.

JC

 

It is just better to stay with the same wheel and tire to be accurate. If you're off it could have a 50mph atv going 70mph. The front tires may be taller than the rear tires. If it is taller then there are more mm's around it. If you take a taller tire and a shorter tire and mark a spot with a piece of chalk on the tires. The taller tire is going to travel a little further than a smaller tire as the chalk mark comes one cycle. So if you measure the taller front tire and put the sensor on the shorter back tire, it is going to show a higher speed than you are really going because the shorter tire is making more revolutions than the front taller tire. The two front tires might not be the same height because one might be worn more. You shouldn't just go with someone elses measurements because their tires might be worn more or less or just a different make. You also should not just go with the number on the sidewall. A 22 tire may not measure exactly 22". The speed could also be off alittle the faster you drive because the tire tends to expand outward. Try to get your speed as accurate as possible so your not posting that your Bayou 220 is doing 60 mph.

Jerms, You just measure the total height of the tire itself not to the sensor. I misread the question and rambled on with the above because I thought you wanted to put the sensor on one tire and measure another. What can I say, It's getting late. I'm just leaving the above because it took so long to type. Maybe it will help someone. When I said to measure the tire where the sensor is mounted. I just meant to measure that tires height. So, yep you're right.[img]i/expressions/face-icon-small-blush.gif[/img]

 

Hehe, been there, done that. [img]i/expressions/face-icon-small-happy.gif[/img] Very good point about tire sizes, though. One brand of tire in a particular size is almost guaranteed to be a little bit different from another brand of the same size. Another factor that comes into play is air pressure. The higher the air pressure the larger the actual circumference.
BTW, I just ordered a Cateye Enduro 8 on Ebay for $22. Can't wait to get it![img]i/expressions/face-icon-small-cool.gif[/img]

 

I looked at the Cateye site. It looks really good and at a good price. Originally, the only reason I bought the Bell was because a local store was going out of business and I bought it on clearance for $8.00. They usually sell for around $20.00 also. It's good to know that there are other choices at reasonable prices. It seems like anything made for an atv is priced high. (Also boats)

 

what should i do bout my tires?? there 20x7.00-8 and what speedometer unit should i get?