Flux Gearing Off?

[Muggydude]

I just picked up a used Savage flux. Has BP Diffs, 44T spur, and a 18T pinion. I will be running some Proline Maxx Masher Tires, badlands, or HPI Supper Mudder Tires. On 4s it (ScriptAsylum Calculator) says top speed is only about 35 m.p.h? Is the preset gearings in the calculator off, or should i buy some new pinions and spurs? I plan on running 4s, 5s, and 6s. Any good starter gearings are welcome. Thanks

Replied at BYT

[bryan]

Originally Posted by Muggydude

I just picked up a used Savage flux. Has BP Diffs, 44T spur, and a 18T pinion. I will be running some Proline Maxx Masher Tires, badlands, or HPI Supper Mudder Tires. On 4s it (ScriptAsylum Calculator) says top speed is only about 35 m.p.h? Is the preset gearings in the calculator off, or should i buy some new pinions and spurs? I plan on running 4s, 5s, and 6s. Any good starter gearings are welcome. Thanks

You really should change gearing for 4s,5s and 6s.They are all different setups.

[_dV]

Given stock wheels, normal Flux gearing is 20T pinion for 4s and 25T pinion for 6s. Use a slightly smaller pinion for heavy wheels, stock wheels are about 300gm. scriptasylum numbers look right to me.

[thzero]

The 25T pinion is just the 'insane' speed pinion, only works with 6S, otherwise its massively overgeared on anything else. But really unless you are going for uber speed runs, 25T is NOT a good pinion.

Standard measurements for Flux on Script Asylum should be 44t spur, 20t pinion, 4S (3.7v), 2200kv motor, standard tires are GT2 (#4462, 6.3") I do believe.

Most of the tires you mention are about the same size as the GT2, but are heavier, so _dV is right you probably want to drop one tooth in the pinion to account for it.

Changing the batteries without changing the gearing just means that truck is going to go faster (i.e. from ~37mph to ~57mph). However temps on the batteries, ESC, and motor may tell you to adjust the gearing. Here is some good advice that I pulled somewhere and keep on hand myself on what the temps are telling you.

Although not always true, a rule of thumb is:
Hot motor, cool controller, cool batteries = undergeared
Cool motor, hot controller, hot batteries = overgeared
Warm motor, warm controller, warm batteries = happy components

Hot, warm, and cool vary as well, so here's another general rule:
Hot for a motor = generally over 160F (71C)
Hot for a controller = generally over 150F (66C)(or "thermal" range for the controller)
Hot for batteries = generally over 150F (66C) for nimh, 130F (54C) for lipo
Warm for a motor = generally 100F (38C) through 150F (66C)
Warm for a controller = generally 100F (38C) through 130F (54C)
Warm for batteries = generally 100F (38C) through 130F (54C) for nimh, ambient temp through 120F (49C) for lipo
Cool for all components = generally ambient temp and up to 10 degrees F (5.6C) more

So it depends on what you want to get from going from 4S->6S. Boost in speed? Don't change the gearing. Even more insane speed? Go to the 25t pinion. But in either case don't expect to be doing long runs before your motor temps go up... especially in the case of the 25t you should monitor the motor temp frequently.

If you are going to 6S to get more power, but better efficiency... then you would need to gear down. Say you want to target 45mph roughly, then dropping to a 16t pinion is probably a good place to start.