This is a universal fit transmission geared for straight axles. Typical use would be Scaler and Sportsman class vehicles.
Ultra lightweight: 42G (1.4oz)
Dimensions: 58mm W x 34mm H x 19mm L (not including output shaft)
Ultra low center of gravity (LCG). The motor sits as low as possible with a stubby type motor. Full size 540 motors require the included spacer under the transmission, meaning they get the ultimate in LCG too.
Heat treated alloy steel gears and output shaft.
Easy 2 hole mounting with extra room for long screws without hitting the gears.
Uses 48 pitch pinion gears from 11 to 18 tooth.
Low gear ratio: 4:1 plus a 44T spur gear.
11T pinion = 16:1 transmission ratio, or 60:1 final (AR44), or 54:1 final (AR44 w/OD gears), or 46.8:1 (AR60)
14T pinion = 12.6:1 transmission ratio, or 47.1:1 final (AR44), or 42.4:1 final (AR44 w/OD gears), or 36.7:1 (AR60)
18T pinion = 9.8 trans ratio, or 36.7:1 (AR44), or 33:1 (AR44 w/OD gears), or 28.6:1 (AR60)
Personally, I like a 40 to 55:1 final drive ratio for most comp rigs or scalers. Crawlers that is, rock bouncers or bashers will want more speed.
What is a good pinion to start with? A 14T (48P) pinion is a good starting point for typical non-portal crawlers, then adjust to your personal preference, and your specific setup. If you are running a fast motor or heavy rig, maybe 13T. If you are running a very light rig or slow motor, or want more speed maybe 15 or 16T. Portal rigs perhaps an 18 tooth starting point (49.1:1 final drive in a Capra with 20/15 overdrive gears).
Chart above shows possible ratios using stock Axial portal and AR44 straight axle gears