Whats your final drive ratio ?

[SouthernComfort]

Whats your final drive ratio on your rig ?

Also tire size as that effects the outcome. .

[Olle P]

I'm using about 75:1 (currently 13T pinion) with HB Rovers. (Different gearing front and rear.)
That doesn't say much unless you also know what motor and battery voltage I use, as well as the fact my truck has worm drives...

[TacoCrawler]

47.2:1

stock SCX-10 factory drive train 87/14

3s LiPo / 55T mtr.

I have not calculated how my current 4.25" (1.9) tires
affect the over-all ratio.

I generally roll 4.19" - 4.30" (1.9) tires

my top speed is maybe 4 - 5 mph

[GraniteBandit]

Toyota Land Cruiser BJ, ~300:1
SCX10 Hilux truggy, ~200:1
Trail Finder 2, ~140:1
Jeep Wrangler ... coming

I love super slow rock crawling like what you'd see in California (Fordyce Creek, Rubicon, Duzy Ershim Trail, Sledgehammer).

The Land Cruiser, SCX10 and Jeep are running worm drive axles with a ratio of 25:1 ... the Trail Finder is running a 2:1 gear reduction unit between the motor and trans. $10 brushed motors in all running 7.2v

Occasionally I get passed by ants.

[SouthernComfort]

Dear God man... 300:1...

[GraniteBandit]

Originally Posted by SouthernComfort

Dear God man... 300:1...

I hear ya. It's ridiculously slow. That one is running the RC4WD R2 transmission and Worminator axles. Eventually the R2 is coming out and getting replaced with the R3 single speed and a 1:1 xfer case.

[Rowdy_Giff]

How do you calculate this?

[Calderwood]

Originally Posted by Rowdy_Giff

How do you calculate this?

Multiply each ratio by the last.


My 1:1 Toyota has a 210:1 crawl ratio . I've never calculated my rc ratios.

[Rowdy_Giff]

So (spur/pinion) x trans ratio x xcase ratio x axle ratio = final drive?

[Calderwood]

Originally Posted by Rowdy_Giff

So (spur/pinion) x trans ratio x xcase ratio x axle ratio = final drive?

Yes.

[chino63]

Originally Posted by Rowdy_Giff

So (spur/pinion) x trans ratio x xcase ratio x axle ratio = final drive?

Yup

[BigSki]

My 14lb. 1/6th scale Jerp comes in at 102:1. With a HH 35T TorqueMaster and a 3 cell LiPo, it goes about a slow walking pace at WOT.

[SouthernComfort]

Im looking at 116:1 with Traxxas Summit wheels.. at about 7-8 pounds im told a 3800kv 4 pole brushless motor wont have the power... and im thinking with that gearing it wont be all jerky at start up ..
I do have my sights set on a M775 gear motor setup with 20:1 that ends up being 99:1 but thats all with a 1:1 from the gear box to the center shaft..

[meatmonkey]

I run all three of my SCX's with a 12 tooth pinion and 87 tooth spur on 1.9 tires ranging from 4.19 to 4.6" tall. Trucks range from 4.5 to 7 pounds in weight.

Comes out to a 56:1 crawl ratio. It's sufficient for precise low speed crawling with cheapo closed endbell 27 turns and 2s power.

IMO you need at least 30:1 to do any real crawling, and anything deeper than 100:1 would be annoyingly slow.