Gearing guesstamate

[MasterCylinder]

what range pinion should be appropriate for starting??

G2 alu Chassis, Racer-X arms & shocks, UE ultralight 8-Spider difs,
2 speed trans, 14-16 cells, Novak HV(to start), strobe slipper/Ofna 51t spur.

Your best estamates would be appreciated.

[Sylvester]

16 tooth pinion, what spur are you using?

[supermaxx4190]

your best bet is to do the math out. i cant remember the ratio of the UE diffs, but its on their website

[RC-Monster Mike]

I would start with a 14 or 15 tooth pinion with that setup. It should be in the ballpark.

[MasterCylinder]

Thanks for the guesstamate,
I am at a total loss trying to figure this kinda thing, as you can probably tell it's all new to me, ...man its really great that you guys are willing to help a struggling stupido here.
I am far below par with the math and what makes it worse; I dont even know the formulas.
I have not bought the Ofna 51t spur yet...I just want to be relitivly sure that Mod-1 1/8" shaft pinions will be available to dial in the truck before I jump in there...If not; I may have to scrap the idea of running with that slipper/spur with 51 teeth.

If any one has any thoughts on this; I would be very appreciative

[RC-Monster Mike]

I believe I may be able to get the mod 1 pinions with the 1/8" bore in 12, 13, 14 and 15 tooth sizes. I am still working on it, though.

[MasterCylinder]

Highly interested Mike,
I think that set-up would make a great foundation to add some real power after I get everything mechanical squared away.

If this dosen't pan out... what other off the rack options, besides stock and/or RRP's slipper ? are left to consider.

What do you guys use with thoes killer motor setups?

[RC-Monster Mike]

I use the stock setup on most, and the Robinson slipper on others. I have one Kipster slipper, which uses the robinson spur gears, but the slipper mechanism works like the Strobe. This is the best on I have (best 32 pich slipper I know of), but I think Kippster no longer offers any products. The stock slipper will hold up if you use 12 pegs and crank it all the way down (don't allow slippage). This makes throttle control very important with these high powered beasts, though, as you can't tune power delivery with the slipper.

Here's a gearing calculator that'll get you in the ball park. You'll just need to knowyour tires diameter and transmission ratio; then you can play with the spur and pinion numbers to see what would be a good starting point. Then check the temps after running a pack, if you can't keep your finger on the motor for at least 5 seconds, you'll want to drop down a tooth or 2 on the pinion.


Gear wizard calulator

Here's a list popular vehicles and their transmission ratios. Don't know if yours is on it though.

http://www.rcuniverse.com/community/gearwizard.cfm

[Chase023]

For using mod 1, is the Ofna 51 T Spur using the Strobe basically it for the spur choices?

[RC-Monster Mike]

Pretty much. A smaller one won't fit the slipper and a bigger one would probably bind with the driveshafts. There aren't a lot of sizes available that will even fit.

[MasterCylinder]

Using the gear calc...It looks like (to me) It might work with 12t to be about where Novak recomende starting.

I could not get the tranny ratio so I kinda guessed 11t pinion + one tooth for the effect of the difs.
Do you think im in the ballpark??

[RC-Monster Mike]

Yeah, I think an 11/51 or 12/51 is around the same ratio Novak recommends (16/72).