Originally Posted by
Roadrash730
ok so i finally got one after haveing a mtx3 for a while i decided to UPGRADE there is a wealth of info on here but i cant seem to find much about the side pullys like what affect the 25 has opposed to the 24 i dont know a whole lot about overdrive ratios i do understand the 1.1 means front and rear rotate at the same speed, but if i measure my tires and come out with say .996 with the 24 tooth does that meen that the front is spinnig faster or the rear is spinning faster?
Any help would be wonderful
Thanks Dustin
Look at overdrive charts for MTX3 or MTX4.
Anything above 1.0000 means OVER DRIVE ( front tires rotating FASTER than rear tires ). Examples : 1.0351 means 1.0000 - 1.0351 = 0.0351 x 100 = 3.51 %. Therefore, front tires is rotating 3.51% FASTER than rear tires.
Anything below 1.0000 means UNDER DRIVE ( front tires rotating SLOWER than rear tires ). Examples : 0.9152 means 1.0000 - 0.9152 = 0.0848 x 100 = 8.48 %. Therefore, front tires is rotating 8.48% SLOWER than rear tires.
Equal to 1.000 means FULL TIME 4WD.
However, since rear tires's diameter are wearing out at faster rate than front tires, we need to give some
tire split by shaving front tires diameter before race. Most split range from 2mm to 3mm. Examples, front tires diameter before race : 62mm and rear tires before race : 64mm. Thus 2mm split.
Why tire split ? Because we can't drive very well when front tires have bigger diameter than rear tires ( I feel like I want to shoot the car ). ..... this is true for racing on long mains. We want driveable car for the whole mains. Another trick to slowdown rear tires wearing out faster than front is using 1 or 2 grade harder compound for rear tires. Examples, 35 shore for front, 40 shore for rear.
For MTX3. I find the nicest setup by going underdrive. Replace the rear side pulley 19T with 18T, and keep using 24T side pulley.
For MTX4. I also prefer underdrive with 25T side pulley.
Anyway, people may have different opinion and driving taste on these...... so please don't take my preferences without further testing on your own.