Lower gearing

[sfatoyota]

Hello, has anyone put a larger spur gear than a 45t on a trx4? I've got a 9t pinion 45t spur allready and I'd like to go a bit lower. Right now the only option I know that would fit is an underdrive ring and pinion.

Thoughts?

Thanks

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[AnimalHippie]

Go to a higher turn motor. I run the Holmes Hobbies Trailmaster Sport 27t with 9t pinion and 45 spur. Top speed in high gear is around 8mph. Not fast enough to blow donuts but enough wheelspeed to get up loose terrain hills. Allot of torque gained that way. Doing underdrive front and rear will slow it down but cost way more then throwing a different turn motor in it.

[KV242]

Originally Posted by sfatoyota

Hello, has anyone put a larger spur gear than a 45t on a trx4? I've got a 9t pinion 45t spur allready and I'd like to go a bit lower. Right now the only option I know that would fit is an underdrive ring and pinion.

Thoughts?

Thanks

Sent from my SM-G950U using Tapatalk

I run 9/45 as well and have looked for a way to lower the gearing further, but have yet to get it done. I'm interested as well if anyone has done something that works well. I've also considered underdriving front and rear, but not sure it will make enough of a difference for the money.

Originally Posted by AnimalHippie

Go to a higher turn motor. I run the Holmes Hobbies Trailmaster Sport 27t with 9t pinion and 45 spur. Top speed in high gear is around 8mph. Not fast enough to blow donuts but enough wheelspeed to get up loose terrain hills. Allot of torque gained that way. Doing underdrive front and rear will slow it down but cost way more then throwing a different turn motor in it.

Going to a lower turn motor is not the same thing as lowering your gear ratio.

[dr frankenstyle]

I'm running an 8t pinion and the 45 spur. I'm also running the all alloy motor mount and a Holmes Torquemaster, but the mod' I did may work on the stock set-up too.
By using the "not quite directly opposite" holes in the motor, and then using the "A" and "3" holes in the mount, the gear mesh turned out perfect. All that is needed is a little filing on the screw holes, as they're a little too wide apart. Here's a pic'.



You can see the screw set-up. It drops the overall gearing over 10 percent. Again, it may not work with all motors, not sure about the stock mount either. But it is an option, and I love the set-up in mine. It's probably part of what gives me an edge over my buddies.
Oh, just remembered .... that motor has a longer shaft, so I made a spacer to set it back 2 mm too.

jim

[sfatoyota]

I have been looking at some of the planetary gear reduction units. Not sure if I'll have enough clearance.

Thinking about ordering a 50t or 55t spur gear to see if I could make that work.

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[mass-hole]

Originally Posted by dr frankenstyle

I'm running an 8t pinion and the 45 spur. I'm also running the all alloy motor mount and a Holmes Torquemaster, but the mod' I did may work on the stock set-up too.
By using the "not quite directly opposite" holes in the motor, and then using the "A" and "3" holes in the mount, the gear mesh turned out perfect. All that is needed is a little filing on the screw holes, as they're a little too wide apart. Here's a pic'.



You can see the screw set-up. It drops the overall gearing over 10 percent. Again, it may not work with all motors, not sure about the stock mount either. But it is an option, and I love the set-up in mine. It's probably part of what gives me an edge over my buddies.
Oh, just remembered .... that motor has a longer shaft, so I made a spacer to set it back 2 mm too.

jim

I did something similar on my rock rey. Running a 9T pinion there when 10T is normally the smallest.