[Rapscallion St Croix]

Originally Posted by mtdjed

If the tire RPM stays the same, then wouldn't actual speed change be a function Pi *D.

3.14* 10/3.14* 8 ?

No. The ten and eight are wheel diameters not tire diameters.

[RickeyD]

Geez, the mph or distance traveled in a given amount of time is a function of the tire circumference and RPM. Hence a larger tire will travel a greater distance then a smaller one at the same RPM.

[RickeyD]

Originally Posted by Bobs GolfCart Speedometer

I've installed over 600 speedometers on carts here in the Villages and have observed the following:

If you switch to 205 65-10 tires you will increase your speed by approximately 2.5 mph. If you buy 205 50-10 tires you will not see any speed increase.

Your screwing this guy up by not explaining the aspect ratio difference. A 65 aspect ratio will have a larger overall diameter then a 50 aspect ratio. That's why the 65 travels faster.

[ajbrown]

I suspect you have all the information you need by now

If you want another option, consider leaving the standard tires and spending about $225 on a Plumquick Bandit rebuild or new Plumquick motor ($325).

High Speed & Performance Electric Golf Cart Motors & Motor Controllers - Plum Quick Motors

Understand with that motor, you are now not a legal golf cart (by definition) since you can exceed 20 MPH, so you have to understand and accept all of the consequences. It is not my intent to preach, just make you aware. FYI, you will not be the only one out there who can go 23 MPH.

[Rapscallion St Croix]

Originally Posted by RickeyD

Your screwing this guy up by not explaining the aspect ratio difference. A 65 aspect ratio will have a larger overall diameter then a 50 aspect ratio. That's why the 65 travels faster.

Assuming the tires are the same width.

[rhood]

Originally Posted by 123Cookie

your speed on your speedometer is based on rotation of tire - when you change the size of the tire - the speed on the speedometer changes - NOT the speed of the cart - you are not going any faster - just your speedometer is no longer accurate!

Ya think ?

[Frank7]

Bobs Golf Cart Speeometers is exactly correct. Changing tires and wheels too 205-65-10
On a Club Car will result in a speed increase of 2.5 MPH.
Speedometers are calibrated in MM of the circumference of a wheel and tire will spin at the max that the carts controller will allow, the increase of rubber on the road with the larger assembly will result in the additional 2.5 MPH.

[village dreamer]

thanks frank

[Topspinmo]

Originally Posted by Rapscallion St Croix

Assuming the tires are the same width.

Width has nothing to do with it. It's the difference in height. Only thing width does is more traction and maybe more torque to turn/spin it. Which with more height on tire the torque going up hill will be less due to the length the tall tire will travel with one rotation. tHis can be measured by marking line on the tire rotate it one revolution and measuring, do the same with the smaller tire. This is the difference in final ratio between the two different height tires.

So the speed cart gains on straight and level may be countered when you climb hills with slower speed and more load on the batteries?

On gas carts the governor will kick in and speed the cart up to almost governed speed within few ten thousands.

[RickeyD]

Originally Posted by Topspinmo

Width has nothing to do with it. It's the difference in height. Only thing width does is more traction and maybe more torque to turn/spin it. Which with more height on tire the torque going up hill will be less due to the length the tall tire will travel with one rotation. tHis can be measured by marking line on the tire rotate it one revolution and measuring, do the same with the smaller tire. This is the difference in final ratio between the two different height tires.

So the speed cart gains on straight and level may be countered when you climb hills with slower speed and more load on the batteries?

On gas carts the governor will kick in and speed the cart up to almost governed speed within few ten thousands.

Dude, don't bother. Not too many gear heads living here, they will never understand.

[Topspinmo]

Originally Posted by RickeyD

Dude, don't bother. Not too many gear heads living here, they will never understand.

When I rented couple years ago a star cart was finished. It ran right at 20 MPH. I noticed high low switch on the dash which I thought was for headlights? Wrong! It was like over drive or another gear. The cart took off from 20 mph up to at least 30 mph. No this wasn't LSV. I guess star had some wiring that threw more volts to the motor? Was nice option, but I only used it once when I discovered it. 20 was plenty fast enough for me compared to life style cart that could verily break 16.

Something else I noticed on the star? Tires had severe in and outside wear on the back?

[Dr Winston O Boogie jr]

As has been pointed out, the increase in speed is minimal. Somewhere around 2 mph. But you will get a smoother ride. Small bumps are not felt as much with the larger tires.

Make sure that you have enough clearance. With larger tires you may experience the tire hitting the wheel well when you hit bumps. You may need to lift the cart a bit.

[RickeyD]

Originally Posted by Topspinmo

When I rented couple years ago a star cart was finished. It ran right at 20 MPH. I noticed high low switch on the dash which I thought was for headlights? Wrong! It was like over drive or another gear. The cart took off from 20 mph up to at least 30 mph. No this wasn't LSV. I guess star had some wiring that threw more volts to the motor? Was nice option, but I only used it once when I discovered it. 20 was plenty fast enough for me compared to life style cart that could verily break 16.



Something else I noticed on the star? Tires had severe in and outside wear on the back?

The switch probably killed half the motor poles thereby increasing your speed. A lot cheaper then an overdrive.

[toeser]

Originally Posted by 123Cookie

your speed on your speedometer is based on rotation of tire - when you change the size of the tire - the speed on the speedometer changes - NOT the speed of the cart - you are not going any faster - just your speedometer is no longer accurate!

A very cheap, easy solution to this problem is to buy a used smartphone (often can be found for $10-15), get a good speedometer app, and your speed will be dead accurate from the GPS system. The app I got also shows direction, odometer, trip meter, and time of day. There are cell phone mounts for golf carts on Amazon and Ebay that are cheap. I probably get 10 trips to a charge.

[tomwed]

Originally Posted by toeser

A very cheap, easy solution to this problem is to buy a used smartphone (often can be found for $10-15), get a good speedometer app, and your speed will be dead accurate from the GPS system. The app I got also shows direction, odometer, trip meter, and time of day. There are cell phone mounts for golf carts on Amazon and Ebay that are cheap. I probably get 10 trips to a charge.

What app do you have? I'm looking for an app that tells me when I'm speeding.