E- revo gearing questions
 

I plan on getting an e-revo, and will be running a quark 125b w/ 7xl...... any suggestions for gearing

What kind of battery setup were you looking at? I've read that the 7xl runs pretty hot, so you would probably be best off to gear for ~40mph.

2s2p (4s) maxxamps 8000 lipo's.....i ran this setup with no issues on my gmaxx & it weighed about 11lbs....

Go to this site and plug in some values.
http://scriptasylum.com/rc_speed/_top_speed.html

Front/Rear Differential Gear Ratio: "Traxxas Revo"
Transmission Gear Ratio: E-maxx (3905) 1-Speed or 2-Speed 2nd Gear"
Spur gear: Assuming you're going to be using 32p (0.8mod); 54 56, 58, 62, 65, 68(Stock)
Pinion gear: These can be had from tower, impaktrc, rc-monster, kershawdesign. (Stock is 19t)


This is what you might be looking at:

Differential Ratio: 2.8461538461538463
Transmission Ratio: 1.8333333333333335
Other Ratio: 1
Spur Tooth Count: 54
Pinion Tooth Count: 19
Total Voltage: 14.8
Motor KV: 2382
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.84 : 1
Total Ratio: 14.82996 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Total Motor Speed: 35253.6 RPM
Vehicle Speed: 40.66 mph (65.32 km/h)
Estimated Adjusted Speed: 39 mph (62 km/h) - 5% loss
Effective KV Value: 2382

You makee a mistake on the spur gear , the stock e-revo spur gear is 68T, mod .8.
So with your 4s li-po, gear it with a 23T 32pitch pinion, and you'll be in the 39-40m/h:wink:

On my e-revo, on 6s, with badland tire (5.85" OD) i'll use a 22T pinion.

You'll be ditching that 7xl right quick, if it lasts long enough ;). It's too hot a motor for something heavy as a Revo. 8xl even runs too hot on 4s in my Revo. My 9xl on 4s is good for only about 15 minutes before it's too warm for comfort.

J.

Maybee you was over geared with your 9XL, because i've run it in a 11.6lbs truggy with excellent result.
DOn,t think an electric revo weight more than 11 lbs.

Well here is all the info in one shot
quark 125b
7xl
2s2p (4s) 8000 maxamps lipo
badland tires

so i should gear it the following
23t pinion
68t spur

feigaos will stay cool if you can run them in a meat locker....:lol:

Yeah i do know that 68T is the stock spur, but i was using a 54T spur that traxxas makes for the jato. Since a spur is cheaper than a pinion, i thought i would suggest another spur(~$3) instead of another pinion(~$12).

that spur would be too small for anything Emaxx wise, you'd need a 28 to a 30 tooth pinion to get any mesh and the gearing would be too much for even the most powerful setups

From a few trials with the E-Revo, don't gear for 40mph with the stock tires. My first gearing was 24/68 on a 1515 running at about 30,000rpm geared for 35mph - at 35 mph the stock tires balloon enough (about a full 2" in diameter)to make the speed closer to 50mph+ and will drop your overall ratio tremendously and you will get some serious heat (got up to 180* on a 1515 in 10 minutes - a 7XL would become a griddle)

I just switched out to a 1515 running at ~36,000rpm on 6S and geared it at 18/62 with the Badlands MT (again ~35mph) and it was running much smoother and motor temps around ~130*.

The badlands do not balloon much at all. The Talons are cookie cutters - if you gear for 40 you're going to balloon close to 55-60mph gearing with the tire expansion.

I would say to gear up to closer to 30-32mph and with a little tire ballooning you'll be around high 30's. When you get better tires you can then gear back down to a 20-22T pinion.

The stock tire on my e-revo is in the garbage:lol: I've put half offset Ofna wheel with proline bowties MTR.
I've a Neu 1515 2.5d/f with 6s, gear 24/68 and i'am about in the 40/42mph range.
If i put y badlands on it, i switch for a 22T pinion to campansate for the extra .15" diameter and weight.:wink:

I'm going to ebay mine to some poor schmoo along with the titans, esc, radio and receiver.

Same motor/bat setup as me, but I dropped the spur to 62 to make use of the low-CG mount. I feel I could go up from 18/62 to 20/62 with now problems as well with the badlands tires. That puts me at the same ratio as you with th 22/68.

That just feels like a nice range for a MT. No need to try and go 50 in a truck..... More fun to go a little slower and use it on the bumps like it was made to do.

Ya:lol: i said " in the garbage" but in reality, i've sell it for $40.00 to a friends ( no, my firends is not a garbage:rofl:)

And all my stock electronic (motors, ESC, Tx + Rx and servos) is ever sold to another of my friend for $110.00.

So my e-revo, with both taxes and shipping is at my door for exactly $382.16 CAD:wink:

What did you want to mean by low-CG mount??? You put your Neu on the front of your truck to the place of the rear???

From the e-revo user manual.
http://i87.photobucket.com/albums/k1...motormount.jpg

I stand corrected.

Thanks - best answer I could give.

Neu is still mounted in the back spot but it sits a little bit lower to the chassis. There is actually somewhere in the manual (or on the Traxxas site - can't remember) a listing of what gear combinations will work with the low-CG mount and the high CG mount.

Using the stock 68 spur gear your gearing on the low-CG mount is limited.

This is a quote from Zinno from the traxxas forums:
http://monster.traxxas.com/showpost....00&postcount=4

"For 2x 550 setup, the info is in the manual. For single motor mount, the range is HUGE:

High CG motor position:
54T spur: 11 - 36T
56T spur: 9T - 34T
58T spur: <= 32T
62T spur: <= 28T
65T spur: <= 25T
68T spur: <= 22T

Low CG motor position (or alternate "big" motor mount):
54T spur: 12T - 29T
56T spur: 10T - 27T
58T spur: <= 25T
62T spur: <= 21T
65T spur: <= 18T
68T spur: <= 15T"

What's "big motor mount"??? Is a Neu is consider to be a big motor??

So if i understand, if i want to run the stock 68T with 22 T pinion i don't have any choice other than put it on high CG??

wowow..if i want to use the 68 spur and a 20t pinion i can not use on low cg position:oh:

Exact my blueberry friend:lol:
That's for this reason that i've order a 62T spur with a 20T and 21T RRP pinion.:wink:

The neu 15XX uses the same size mounting as the titans,... that can be used in the low and high CG mounting places. The Big motor mounting option is well......bigger...Its for 29-30MM set motors like this;
http://www.hobbycity.com/hobbycity/s...hless_Inrunner

Also Don't worry about the term "high CG". It's all of about 4mm higher than the other one. I think the only point of the two different smaller mounts is to give more gearing options. Still way lower CG than the e-maxx mount.

wow....hmmm, now im not sure how to gear...think i may start out with 22/68

I would recommend start out with a 19 or 20T and go from there based on performance.

I think that with my 1515 2.5d and 6s, i'll be not to bad with 22/68, but i've RRP MOD .8 pinion 20T and 21T on the way:intello:

David - you and I are running the exact same setup with the badlands - and running last weekend on 18/62 (equiv to 20/68) I can see 20/62 (24/68) being a good setup - but the badlands really don't balloon too bad.

You had recommended the badlands setup to me in a pm and I got the tires with the maximizer bead locks and they are a perfect bashing combo.

With the regular stock Talons you might as well take the diameter of 5.9" and add an additional 2" to the diameter if you gear for 35 or more.

SJCRSS - if you have the options of getting a few pinions I would go low and then work your way up, but either way you will love this truck - I've been having a blast with it so far.

I'll try 20/62 at first, and if my component is to hot to my taste and runtime to short, i'll drop it to 20/68:yes:

Regardless of motor or battery - if your setup is going to be around 30,000rpm - do not run 24/68 with the stock tires - you'll overheat the motor when the wheels balloon because the motor will be way overgeared at speed.

I have a set of Badlands and Maximizer beadlocks also , they are still in the package waiting to be assembled I am presently running a set of LPR Crimefighters on my BL Revo

i can get a few pinioins, i just need to figure out the range of them.....so im guessing for the following ...using the stock 68p spur....
20t pinion thru 24t pinon......am i correct in this info?

Just order a pair of RCM hybrid V" diff (buggy ratio) for my e-revo.

Ho! I've recieve it today, great machine, but the front diff have a defect on it, the pinion gear is bad, can't turn it a completed turn:lol:

That's my reason to order the V2 hybrid diffs:lol:

I'll gear it 24/62 with this ratio for about 41m/h

Sorry to revive an old thread - Just read through this when doing a search for something else.

For everyone that has posted that the Talons are junk/balloon to much I think you need to try something, try re-gluing the tires or don't use pre-glued ones. I'm running a Tekno 1515 2.5d on 6s. I started with my 17mm Maximizer beadlocks/Badlands(taped on the inside because THESE become dinner plates) until I lost a wheel nut. Not having a spare nut and not wanting to be down waiting for one I took off my 17mm adapters and put the stock 14mm hexes back on along with the talons. I previously cut the tires off the rims, cleaned everything up and took my time re-gluing them. The Talons provided much better grip on ashphalt and even ballooned less than my taped badlands with 20/62 gearing on 6s.

Not trying to start a battle over tires, just wanted to point out that Badlands DO balloon to dinner plates unless taped and talons can be used when securely mounted.

You are right. I have a maximizer/badland combo on my erevo and they ballooned to a huge size before I taped them. I also balanced them, which made a huge difference. It is geared for around 42mph and it is smooth as silk at that speed. I have also had great success running the talons on stock traxxas wheels. Never really noticed a problem with them, even bone stock.

I re glued my talons, and don't really see any need to use a more expensive tire/wheel combo. They tires offer great, I run a 2100kv motor on 6S with 20/68 gearing and the wheels do balloon at WOT but nothing too scary. Once re glued they've been flawless.

Edit: What size badlands and maximizer rims are you guys running? I have no idea about these after market wheels :(

any suggestions guys on a tekno converted revo? currently using a 40t spur (stock)with 15t pinion 1 metric pitch. truck has disturbing amount of torque compared to the dinosaur 3.3 it replaced. just curious who is running the same setup.

Badlands MT tires with Maximizer beadlocks - 17mm hex - Ofna 17mm conversion

If you haven't already found this http://scriptasylum.com/rc_speed/_top_speed.html
you should try it! It will quickly become your best friend! Brushless will have more torque than a nitro period! Depending on your motor and voltage your running that could be the issue. Too big of a motor or HV will give more torque, more wheelies