Lower gears for RXV

Monstermaker

I’m an old gearhead/hot rodder type, new to carts. I bought a 2015 RXV to get around my property on, because they have a limited slip and I got a decent deal on it.
Of course I’ve got the bug to lift it and put big wheels on it... and being familiar with cars and trucks I know what that will do to the gear ratio.
I don’t want to try to compensate with more power, I think that’ll still suck.
This thing needs to climb hills under a load sometimes.
I’ve managed to order a set of the somewhat elusive Jacobsen Eclipse 332 lawnmower 19.63 gears that are supposed to fit in an RXV rearend. I’d rather regear lower for the big wheels like you do (if you’re smart) on a truck.
I’m plodding into this somewhat blind.
Has anyone else done this gear swap and have anything to say about it?
I see a lot of talk about bigger tires and upgraded controllers and wiring to get the power back and almost no mention of just putting in lower gears like I’m intending to do.

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

BobBoyce

I hope the gears fit and the limited slip unit will fit the gear. Stock gear ratio in the RXV is 16.99:1
I commend your plan, because so many do not consider the stresses placed upon the motor and controller when larger tires are put on an RXV.

Monstermaker

Well my 19.63 gear set arrived. When I can find any time at all to play with it I’ll bolt ‘em in.
I think they might be fun even with the stock tires. The thing should really pull.

OttyFields

Make sure there are plenty of pictures...lol

Sent from my SM-N960U using Tapatalk

JohnnieB

FWIW: The motor will be spinning 15.5% faster for each axle revolution, so you'll get about 15.5% more torque with stock height (18") tires, or you can install 20.8" tall tires and get stock performance.

IIRC, Bob says 20" tall tires are the tallest that can be installed on a RXV with stock gears without having to do some major reprogramming of the controller and that translates to 23.1" tall tires with your 19.63:1 gears.

--------------
I'm sure I'm preaching to the choir, but the explanation is for the non-gearheads that may read this thread.

Monstermaker

I’m also thinking I could get pretty good size tires on without lifting.
Just for grins I bolted the 22” turf tires (on 12” wheels) from my lawn mower on the cart (rear only, I only had two) and tried it out, totally stock. The rubbing was just against some plastic inside the rear wheelwell and I think I could just trim that.
If there was any issue with the fender openings I think I’d just radius-cut them and add flares so it looks “finished”.
My property has some gnarly slopes that I need to cross sideways and I don’t want to raise the center of gravity. The further up you go the sooner you roll over on your side!

yurtle

Not so much "preaching to the choir" as I totally ignored motor RPMs at high speed, until another member's motor exploded, possibly due to RPM. I'm attaching a spreadsheet JohnnyB created, that allows RPMs to be calculated from speed, gears, and tire diameter.

I've been known to do 37+ mph downhill with the wind at my back with stock tires, which results in 8,916 RPMs.

Just something to consider. You'll have to decide what's a "safe" RPM for your motor. I think I remember Bob saying some RXV motors may be good up to 10k RPM.

Bob, is this correct?

Attached Files

Tire height and Gear ratio.zip (13.9 KB, 0 views)

BobBoyce

12K is max at the Curtis AC controller drive RPM limit. E-Z-GO limits at 8000 to 9500 in the VCL, depending upon the application.

cgtech

The general construction design of the rxv motors rotor inherently affords some more rpm. It doesn't have soft copper windings in the rotor to sling out and cause hell..

yurtle

Gotta love (Nicola) Tesla's brushless polyphase motors.