Gearing question.

[GALLERY=media, 219]IMG_0823 by MnWade posted Jan 20, 2017 at 9:51 PM[/GALLERY]

We're putting these new tires on my kids Amp MT's. They stand easily a full inch taller than stock. Do you think I'll get away with the stock gearing or not? If not would I be better off to change the pinion or spur gear? I'm new to the electric side of this hobby so any help is appreciated.

Thanks in advance!

I would for sure be checking temps with a temp gun. I think they will run too hot with stock gearing.

When I run my stock amp (albeit on lipo) in the grass, the motor gets up to 180F. If you run yours in the grass with those tires, it's gonna fry. You'll probably need something like a 14T or 15T pinion to get near the stock gearing if they really are an inch taller.

I'm thinking 15t. They're about the size of a Stamede tire. The kids really want monster trucks so we'll make the adjustments.

Also have a question about gearing. (not to hijack the thread)

I just purchased this SkyRC Cheetah 2590KV 13.5T Sensored Brushless Motor CS60 60A ESC combo
I'll be running 3s Lipos. I've replaced the plastic trans gears with the metal kit. Also replaced the plastic driveshafts with the metal kit as well.

My concern is pinion an spur gears. Do I need to change the ratio?
And does anyone have info for metal upgrades on these? I'm worried about chewing these stock ones up fast with this new added power.

I would see where you are at first before you change the gearing. Speed and temp wise.

You can get a metal spur if you want (HR has one I think) but a cheaper and quieter route is to upgrade to a 32p spur and pinion. Team Associated 32p spurs work if you drill out the hole to 5mm (need a metric drill bit), with common 32p pinions (Robinson Racing, Traxxas, ...).

I just came across this in my search.
http://m.ebay.com/itm/Hot-Racing-EC...ear-SECT881-/291932539147?nav=WATCHING_ACTIVE
Does anyone have a review on this product

I have that and it has been solid with my 3s and 2s batteries. More noise comes from the metal differential than this.

Get new slipper pads, don't bother trying to remove the old ones. They are stuck on with double sided tape and don't come off nicely/easily.

sc302 said:

I have that and it has been solid with my 3s and 2s batteries. More noise comes from the metal differential than this.

Get new slipper pads, don't bother trying to remove the old ones. They are stuck on with double sided tape and don't come off nicely/easily.

Click to expand...

Good to know. Did you keep stock spur gear? I'm also replacing diff gears to metal along with the Cv axels and have 3s Lipos on there way

Kept the stock gear until it broke. Then I went up 2 teeth.

I guess I over tightened it.

RC Rebels said:

I just purchased this SkyRC Cheetah 2590KV 13.5T Sensored Brushless Motor CS60 60A ESC combo
I'll be running 3s Lipos. I've replaced the plastic trans gears with the metal kit. Also replaced the plastic driveshafts with the metal kit as well. And does anyone have info for metal upgrades on these? I'm worried about chewing these stock ones up fast with this new added power.

Click to expand...

I dunno. I race my Circuit with stock plastic transmission gears, a 72t AE plastic spur gear AND a 175RC plastic (yes!) 28t pinion all with a 13.5t motor (granted, only on 2S).