spawn regear questions

[riverside_wraith]

So I asked this question in another thread but didn't get the answer I was looking for...
my spawn came with a stock 12t pinion gear.. 32 pitch..
my question is what size pinion should I run with bigger tires? I geared down to an 11 tooth pinion/64tooth spur but my motor is still getting hot.

I am running steel gears in the tranny as well as a 64tooth steel spur gear from a yeti paired to an 11t pinion.

Here's a pic of the tire upgrade.


How many teeth should I gear down on the pinion? Right now I'm one less than the stock pinion gear

[Eric0424]

You don't have many options left, a 10 or 9 tooth is about it in 32 pitch pinions and I think the 64 tooth is the largest 32 pitch spur gear you can run. If a 9 tooth pinion is not low enough you could install the 43/13 axle gears front and rear to get your FDR a little lower.

Also check your Spawn for binding or seized bearings in the drivetrain and double check your gear mesh to make sure it's not too tight, if you haven't already done so. These can cause overheat.

[riverside_wraith]

Where are some common bearing failures and how can I test them? I've spun pretty much everything with my fingers to feel for any binding, but I havnt taken apart the transmission since I put in the all metal gears.

[SoCal Crawlr]

I would buy a 27t axial motor to replace the stock one. Don't go through the hassle of trying to redo your entire truck for a $10 motor. Ebay has them for around $10 shipped I believe, or most of the major retailers will also have them for cheap

If you have a bearing seize up you'd definitely know but its not impossible that you're binding somewhere in the transmission. What is the ambient temp outside when you're running? how hot is your motor getting? Are you using a temp gauge or just testing it with your finger? what battery?

[Eric0424]

Originally Posted by riverside_wraith

Where are some common bearing failures and how can I test them? I've spun pretty much everything with my fingers to feel for any binding, but I havnt taken apart the transmission since I put in the all metal gears.

Generally your wheel and hub bearings are the most frequent failures, but the axle pinion bearings are also a known problem with some. About the only way to check them is to spin them. If you want to check the transmission, just pull the pinion gear off the motor and disconnect the drive shafts from the transmission. It should spin easily, if not you may want to open it up and check each bearing.

It's also possible your motor is just worn out or damaged depending on how old it is or how hot it's gotten if it's been overheating. If it's gotten hot enough to do permanent damage then it's probably going to keep getting hot no matter what you do.

[Duuuuuuuude]

Seeing the mud on your rig, a failed bearing is likely, and/or a toasted motor.

If lots of mud/water is what you play in, then keep buying the cheap rtr motors or make the switch to brushless (much easier to waterproof).

If not, then going to a quality motor (Holmes or Brood) will be money well spent. The extra power will open up your gearing choices.

Another option is to replace the diff gears with the underdriven HD sets (you'll eventually want to go HD anyway).

[riverside_wraith]

I live in so cal so Temps are about 80 right now. I switched to a 55 turn motor and the heat issues seemed to resolve. But that was way too slow for me so I bought a brand new stock 20 turn that's about 4 days old now and this thing heats up quick, I don't have a temp guage I just use my finger..I could fry an egg on this thing.

but I love how fast it is. I'm running a 2s lipo 7600mah and rarely go through mud anymore.. those pics were from when I first got it.. I have since learned my lesson lol

My main goal is to have some decent wheel speed but still have enough torque to turn theese tires without frying motors..
is gearing going to be enough on the 20 turn motor or should I get a decent motor in the 35 turn range like stated before? The 55 turn was so slow and boring

[Duuuuuuuude]

The best way to get torque and speed along with reasonable temps is to up the voltage. 3s works great in just about everything.

Upping the voltage means you can run a higher turn motor to get the bottom end torque while the higher voltage spins the motor faster at the top end for the speed. You'll still need to gear accordingly though.

[riverside_wraith]

I just ordered an 8 and a 6 tooth pinion from rc4wd, there hardened steel To go with the steel spur gear.

I'll let you know how much they affect the heat on the motor I havnt found many people gearing the spawn down so low. I probably won't run the six I just wanted to test it out.

[riverside_wraith]

Figured I'd show you guys What I usually wheel in .. I built a pretty rad trail in my backyard it's got a dump and bump.. a couple ledges few hill climbs and two rock gardens. One sandstone and miscellaneous rock and the other is a granite and cement slabs. Workin on a river rock waterfall that will feed my peach tree. That's what the palats are for

[riverside_wraith]

Got my new pinions in the mail today.



so far I've tested the 8 tooth for about 15 minutes..the motor was barely warm...so that's a step in the right direction..
tomorrow's my day off so ill get s more in depth test then I'll let you guys know


So my current setup is an axial spawn with the stock 20 turn motor 8 tooth pinion to a 64 tooth spur with 5.75 irok swampersmaking an 8:1 ratio

[DUWraith]

I didn't know you could get such a low pinion count in 32P. Whats the Spur ?
I'm running 13/87 in the other pitch (56?) so would want to match that at least.

[riverside_wraith]

The spur is the steel 64 tooth from a yeti. I had to remove the dust cap so it would fit. And the pinion is a hardened steel 8 tooth long from rc4wd. I really like it so far I played with it for about a half hour lastnight and the motor was a little warm after.. I could hold my finger on it for about 5 seconds. Much.. much better than before. The esc was just starting to get some warmth to it i wouldn't call it warm.. but it wasn't cold metal so I think I still have room to go lower.

Someone correct me if I'm wrong.. you just divide the two numbers right?

This is the gearing setups I've went through

origional spawn gearing
56÷12= 4.6 :1...motor gets too hot to crawl with larger tires...stock tires are ok but anything larger will smoke the motor

64÷11= 5.8:1.. still getting hot too quick with the taller tires but run-able

64÷8 = 8:1? Motor is warm to the touch, crawls fantastic. so far best combo with the irocks

64÷6= 10.6:1 havnt put it on yet. But might be the magic number if I step up to a 3 cell lipo. We will see what it does to my ESC temp. I'll try and run it later today.