Ezgo Marathon 36 to 48 volt conversation

[JohnnieB]

Originally Posted by Sir Nuke

yeah Johnnie....its always a bad thing when you have an unexpected "Energetic Disassembly".

It didn't disassemble, it glued itself together. I still haven't gotten it apart.

[Sir Nuke]

oh that's right.....excuse my French! lol

[JohnnieB]

Originally Posted by Olman

Johnnie--They didn't give me an rpm. I guess I could ask them however. I told them I had 20 inch tires though. I just measured my tires (diameter front to back with tire pressure at 22 psi) at 21 inches exactly. No wonder I lost so much torque when I first put them on. I thought they were 20 inch as advertised. Since the tires are 21s, maybe I'm safe at 30mph.

I can't reprogram but I can back off the skinny pedal.

Some manufactures list MTD (Mounted Tire Diameter) for their products, but most don't.
IE: Carlisle lists two "Turf" tires in 18X8.50-8. The Links is 17.4" tall while the Turf Master is 18.3" tall. Same size stamped on the sidewall, but almost an inch difference in mounted height.

To get the most accurate tire height, put a chalk mark on the sidewall and road where the rubber meets the road and move the cart until the chalk mark touches the road again and make another chalk mark on the road. The distance between the chalk marks will be the circumference of your tire and to reduce measuring errors, move the cart further and divide the distance between chalk marks by the number of times the tire revolved.

A 21" tire has a circumference slightly under 66", so it should turn 10 times in about 55 feet.

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With 21" tires, your motor is only spinning 6K at 30 MPH (5,974 RPM) and 6.5K is reasonably safe for most cart motors, so you ought to be able to take it up to about 32.6 MPH (6,491 RPM) without pushing it too hard.

I did my stock motor in going down a long incline at full throttle and when I lifted my foot to slow down for the turn at the bottom of the hill, the regen braking kicked in hard and moments later the rear tires started sliding. I believe I had spun the motor faster than 7,600 Rpm going down other hills, but I had never lifted my foot at that speed.

I'm pretty sure I have all the GPS data for the run and others I made while running a DCX400 and a stock PDS motor. If so, I've got a program I can replay it on and find out exactly what my speed was.

[Olman]

Thanks Johnnie. That makes me feel better about doing 30 mph. I don't think this setup will top 30 anyway. Probably a good thing in the long run I guess. Handling is a little dicey at 30

[JohnnieB]

Originally Posted by Olman

Thanks Johnnie. That makes me feel better about doing 30 mph. I don't think this setup will top 30 anyway. Probably a good thing in the long run I guess. Handling is a little dicey at 30

Lifted carts tend to be top heavy, but adding spacers to increase the track width will offset it some.

MY cart is stock height and the tires are only 18.3" tall, so it felt pretty stable at 30+.
However, sliding to a stop at from 33, or so, was a wee bit exciting.