Kraton Downsizing Pinion?

[Daywalker_27]

Just serviced my V5 6S Kraton and for the life of me I couldn’t set the gear mesh I was aiming for. I’ve got the motor pushed in the motor mount as far as I possibly can and it’s still not where it should be. I stopped by my LHS to ask for help and the first thing they asked is how much did I downsize my pinion?

I went to a 11t (from the 12t) due to my belted 3.8“ Pro-Line Trenchers causing frequent overheating issues (didn’t overheat no where near as much before the Trenchers). I’ve had several suggestions that I downsize pinion size to combat the overheating. Now my LHS is telling me that the 12t is the smallest pinion meant for the Kraton 6S.

Surly there must be someone here that’s downsized pinion gears on a Kraton 6S, so how did you make it work?

 

[nomis38]

Ive not ran that small of a pinion on a K6 but I will say if your motor is pushed all the way towards the spur and your mesh is still sloppy and to loose then yes that is as small as you can go. 12t i guess

 

[Garcbomber]

The best solution would be to run a bigger can with lower kV for better thermal properties when regearing. 4074/2050kV is really a 4S MT bashing motor, works fine for a light 6S rig or someone who isn’t “full trigga” most of the pack.

On a budget pinch you can go 52T spur and gear down that way.

 

[nomis38]

Yeah if there are options to go bigger on spur that would fix your issue and help even more with lowering gear ratio. I've not looked at bigger spurs, only smaller. As for replacing the motor that may not be in the pocket book of the OP, not sure. I'll look for a bigger then stock spur that fits the stock diffcase.


Edit:

I am not saying to buy this one, but it would seem to work, just letting ya know i guess they are out there, as Garcbomber said.

https://www.amazon.com/dp/B0BLZ6LGG...industrial&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw

 

[SrC]

12T is smallest that will fit for an acceptable mesh. 12 or 13T is the stocker if I remember. The Noto maybe? K6S and 6s Noto run one or the other. Don't remember
Just 11T will not work with the 50T spur on the stocker M. Mount. You are not set up right there. No need to drop that low.
Change out the spur if you want to really get into things, going a shorter, lower ratio.
Not sure why you need or want 11T to begin with. If for heat reasons, you are way low already. Consider the motor you are running, or other ways around this.

The best solution would be to run a bigger can with lower kV for better thermal properties when regearing. 4074/2050kV is really a 4S MT bashing motor, works fine for a light 6S rig or someone who isn’t “full trigga” most of the pack.

On a budget pinch you can go 52T spur and gear down that way.

+!

 

[slick2500]

I'm going to have to agree with @Garcbomber here. The stock power system is already pretty much at it's limits for offroad use. Gearing down will just make the car slower and less responsive imho.

12T is smallest that will fit for an acceptable mesh. 12 or 13T is the stocker if I remember. The Noto maybe? K6S and 6s Noto run one or the other. Don't remember
Just 11T will not work with the 50T spur on the stocker M. Mount. You are not set up right there. No need to drop that low.
Change out the spur if you want to really get into things, going a shorter, lower ratio.
Not sure why you need or want 11T to begin with. If for heat reasons, you are way low already. Consider the motor you are running, or other ways around this.

+!

12t for the Kraton and Notorious, 16t is the speed pinion. Idk why but I could have sworn the Noto was 13 or 14t.

 

[Daywalker_27]

Not sure why you need or want 11T to begin with. If for heat reasons, you are way low already.

Yes, it was due to the frequent overheating after switching to belted wheels. I was told to watch for overheating after the switch in which I was told that downsizing the pinion should overcome the overheating issue.

 

[nomis38]

Yes, it was due to the frequent overheating after switching to belted wheels. I was told to watch for overheating after the switch in which I was told that downsizing the pinion should overcome the overheating issue.

I'd Just run it and check temps sir. Temps are also massively dependent upon your outside ambient temperatures where you live.

 

[Garcbomber]

Thinking about this more, I’d make sure your drivetrain bearings are fresh especially in the motor if you aren’t constantly wide open on hot days. A Kraton should be able to push the tire around decently without overheating in normal temps with box gearing. Ensure your ESC fan has all blades/fully operational and get a motor fan.

Next time the pinion/spur are out of the way, confirm it rolls freely on all 4 and coasts a bit before coming to a full stop. Same with the motor when you let off the forward/reverse with 0% drag brake.

 

[GraniteFox]

You could just look to install some high speed fans for the motor and esc....it not running currently. I would say check to see if you have some bad bearings causing friction but you said you just serviced it. Those belted proline 3.8's are very heavy.

 

[Senton_Prime]

Drop the timing way down, should help considerably

 

[nomis38]

Drop the timing way down, should help considerably

Always a great option I most times forget to tell people.

 

[Daywalker_27]

Drop the timing way down, should help considerably

Explain more about timing please, I’ve got no experience with this. I do have a programmer for adjusting the timing, I’ve just never tampered with this.

I'd Just run it and check temps sir. Temps are also massively dependent upon your outside ambient temperatures where you live.

This summer was hot and it’s been parked for the winter.

 

[SrC]

I'd Just run it and check temps sir. Temps are also massively dependent upon your outside ambient temperatures where you live.

+1
Tru dat.
I just never heard of belted tires necessarily causing way more heat, unless they are super heavy or way larger than Non belted stock tires.
A "proper" Fan solution is critical and always a given. what I would look into. With Temp gun in hand.
Leaving the 12T pinion in there.

 

[slick2500]

Drop the timing way down, should help considerably

I keep forgetting the Firema 150a has adjustable timing.

 

[Daywalker_27]

A "proper" Fan solution is critical and always a given. what I would look into. With Temp gun in hand.
Leaving the 12T pinion in there.

I’m running a PowerHobby heatsink with dual fans

 

[nomis38]

I’m running a PowerHobby heatsink with dual fans

I agree with SrC, you should be good man. Check temps. But im willing to bet even on a hot day you'll be fine with the 12t. Lord knows i've ran mine with giant heavy tires with more gearing that that all weekend without it blowing up.

 

[SrC]

I keep forgetting the Firema 150a has adjustable timing.

Zero timing for me. Your motor will thank you too. Default is like 22.75 degrees or something. That is just crazy high IMHO.

I agree with SrC, you should be good man. Check temps. But im willing to bet even on a hot day you'll be fine with the 12t. Lord knows i've ran mine with giant heavy tires with more gearing that that all weekend without it blowing up.

My K6 now runs a 16T ( stock elec.). 15T is probably its sweet spot with stock electrics.
Fans, fans, fans. Get your cooling solution sorted out first. Make sure Motor BB's kept lubed. Also reduces heat.

 

[hobo]

dropping one tooth on the pinion wouldn't do anything anyway

 

[SrC]

Yeah usually 2 Tooth changes are made to notice a difference with gearing. A 10T pinion will never fit.
That's too low a ratio ayway. You will be over revving the motor and for longer. That can cause high temps as well.
Get good fans and Lower the Motor Timing all the way down. Test with the 12T Pinion from there. If it runs cool now, try a 14 or 15 pinion. Only a temp gun can assist you from there. Simply touching the motor with your finger doesn't tell you how hot it is..