RTR Wraith gearing help

[duramaxcj5]

My little bro has an RTR Wraith that we have been modifying to be more of a crawler. We put in a 35T motor for more torque but it seems to get really warm after a while. I believe by lowering the gearing this will be solved, am I right and if so what spur and pinion combo would be a good choice?

[wheelhead4x4]

I would start with a 84 spur gear an 16 pinion. And work from there.

[allanon1965]

if you are doing more of a crawler, switch to the 32 pitch gears, 56 on the spur and 14 on the pinion. I got mine from robinson racing products and its great for crawling, much better than stock!....my holmes hobbies 27T motor stays pretty cool... i can keep a finger on it without any issues after running 2s lipo thru it.

part number 7856 Traxxas Slash 2WD GEN3 Slipper Unit - 0.8 module 56 Tooth Steel Spur/Slipper Pad/Backplate/Bearing http://supershafty.com/product.php?id_product=110
part number 0140 Steel Alloy 32 Pitch Pinion 14 Teeth http://www3.towerhobbies.com/cgi-bin...?&I=LXAGVZ&P=M

this keeps the stock ratio of 4 to 1 which for me has been great for crawling and decent speed as well..

you can see more on my build thread...
Allanons wraith upgrade

[k7zpj]

If you haven' read it yet, Read Harley's thread:
Choosing a motor and ESC for your Wraith - Gearing Added!

The stock gearing 80/20 is 4:1. To keep the motor cooler you need to be closer to 5:1. As wheelhead4x4 recommended above I would start out with 84/16 and then check the temps.

If you don't have a 84t spur, I would use the duratrax 56 t 32p spur gear DTXC9397 along with a RPP 11t 32p pinion. That would give you a 5:1 ratio and move you to 32p and keep the cost around $10 with shipping.

DuraTrax Spur Gear 32P 56T Nitro Evader BXModels
Robinson Racing 32P Pinion Gear 11T

[meatmonkey]

If your only crawling with a brushed 35 turn you don't really need the 32 pitch gears. My Wraith has been getting by just fine with 48 pitch gears for over two years now.

I'd suggest you pickup up a 12 tooth pinion and 87 tooth spur for a 7.25 ratio. I don't think you can gear 32 pitch as low. Even a 60 tooth spur (which I think requires ditching the spur cover) with a 9 tooth pinion is only 6.667

[k goodrich]

Min i would go is 5.5:1 For my daughters i went 14/87 and the stock motor has lasted 3 years.

[crawler nut]

[QUOTE=allanon1965;4502694]if you are doing more of a crawler, switch to the 32 pitch gears, 56 on the spur and 14 on the pinion. I got mine from robinson racing products and its great for crawling, much better than stock!....my holmes hobbies 27T motor stays pretty cool... i can keep a finger on it without any issues after running 2s lipo thru it.

56/14 is exactly the same as the stock ratio and is not low enough. For a crawler he needs to be somewhere in the 56/10-11 range. 56/14 will burn your motor up. That's why most change the gearing right out of the box.

[allanon1965]

just a question here, but why would stock gearing burn out a better motor like the HH 27t motor I bought? its not getting hot at all and still retains decent speed and crawls very well.. I can understand if the motor was overheating, but...its not. my stock motor didnt get hot either but wasnt as much torque.

just trying to learn here...

[67mustang]

Gearing can be whatever you want it to be. Personally i think going from 4:1 to 5:1 isnt really much of a difference. If your motor is getting hot at 4:1 it will probably get hot at 5:1. 5:1 could actually make it worse if the user tends to bash and run at top speed alot. The car wont be as quick. You have to take desired run speed, motor speed, gearing, and terrain into account. Running in a boulder patch is much different than dirt parking lots or gravel.

[allanon1965]

Ok, i tried several different pinions, 10,11,12,13 and 14

56/10= 5.60-- this was good for only crawling, no speed to speak of and not alot of wheel speed to help cleaning out the tires of mud and such

56/11= 5.09-- this was also really best at crawling, a little better wheel speed, but not much

56/12= 4.66--this was a good combination of crawling and wheel speed and I think would be a good compromise between crawling and rock racing/trail running

56/13=4.30--not bad crawling, seemed to strain a bit on the more difficult crawling challenges but better wheel speed

56/14=4.00--stock ratio, crawls ok, but strains for sure on the more difficult crawling challenges, had the best wheel speed. I think this would be great for running trails/rock racing with no heavy crawling challenges

I went with the 56/12 combo on mine.

hope this helps temps never got too hot on any of the combinations, although I would suspect the 4.00 and 4.30 may get the motor warmer than the others if you run heavy duty crawling courses with no short flat runs to help cool the motor down.

[hulsty]

Hey guys, from the beginners guide, with a stock Wraith RTR I should be looking at 84/16 gears. I'm a newbie to this sort of thing, do I just need a spur and pinion to do the change or other parts required? 48P or 32P doesnt really matter as long as they match?

thanks

[hulsty]

Also does the type of gears matter?

I was looking at the following

Traxxas TRA4684 84 Tooth, 48 Pitch Spur
Robinson Racing RRP1016 16 Tooth 48 Pitch Pinion Gear

[allanon1965]

I would go 32P because it gives you more contact area on the gear teeth, if you go up in power or battery size you will need it. Some prefer the weak point to be the spur gear, I personally do not. I went metal spur and hardened pinion, this is make more noise than the plastic spur, but I dont care, I prefer to hear the noise as it helps me determing motor load and also wear on the teeth (I am a retired ASE Certified Master auto technician).

I think your gearing is fine for crawling but it wont have much in the wheel speed department, depends on what you are looking for, try it and see how you like it.

[Cmarcan167]

i want to go 32p as well. looking at 56/12. will traxxas spur and pinions work because my LHS has them in-stock.

[Ammo Troop]

This info is great but I'm still having problems with the math. On my wraith I have a matrix Pro lathe 55T, Spur is 48p-87t and the pinion is 32p 13t. This is giving me a 51.48 ratio. I seem to have lots of climbing power but NO wheel speed. allanon1965 mentioned in his post several options and he's using the 56/12. Allanon1965, What motor? The biggest confusion I have, is on the crawling post A Lot of crawlers are using 55t motors and seem to do great, I have stock gears in the axles, Do I need to change them? With a 55t what pinion and spur should I use? I've read tons of info on gearing, Motors, ESC but I haven't found anything that matches or couples motors to gearing. I did have one reply that said "the 55t was the wrong motor for the wraiths capability". Any help would be great.

Ammo Troop

[allanon1965]

I am running a holmes hobbies 27T torquemaster sport 540 motor with my 32P 56t spur and 32P 12t pinion, you state your using a 48P 87T with a 32P 13t, I hope this is a misprint, you cant run a 48P against a 32P you need the teeth pitch to be alike, 48P to 48P and 32P to 32P..

I also switched my ring and pinion gears in the differentials to the 43T/13T to give a bit lower ration in the differentials. I dont do uner/overdrive in the differentials due to more stress on the driveline, I dont crawl 100% of the time and dont think its necessary.

I like the speed of the 27T verses the 35 or 55 turn, and with the lower gearing of the diffs, it allows me to do what I want, and still crawl very well. I have been climbing up my door with no issues, it will vertically climb my door until gravity takes over and it flips backwards...but when starting out facing the door, it has no issue going right up the door.

no bogging down or hesitation at all...

motors to gearing is going to be a personal experiment most likely, alot of people go brushless and sensored brushless, but I see no need...I have a couple exo terras for go fast bashing and also a 4x4 slash...they are all brushless..

I am going to get a 27T holmes handwound motor next for the ultimate power as I see it..my 27T was already twisting stock driveshafts...so I have plenty of power. I went to MIP drive shafts and some other upgrades are coming..

[redsawacs]

I would say you have something binding if your motor is getting hot. Also, 32p and 48p gears don't work together. If you have them crammed together, that's why your motor is getting hot.

[axial 4x4 crawler]

It is the gearing for sure, I would run 80t spur and a 15t pinion, that is what I have on my ridgecrest and which it has a 55t motor but anyways you don't need 32p gearing 48p will be just fine. The 15t pinion may seem to much but it will give that 35t more torque and make it cooler. - axial 4x4 crawler

[Jus]

Originally Posted by allanon1965

I am going to get a 27T holmes handwound motor next for the ultimate power as I see it..my 27T was already twisting stock driveshafts...so I have plenty of power. I went to MIP drive shafts and some other upgrades are coming..

You're going to love it. I have found the 27T HH Torquemaster Pro to be the perfect crawling/trail running motor for the Wraith. It's just awesome. Mine is geared 87/14 and always on 3s power and it's just a hoot and a half. Two years now still running the plastic 48p spur and steel pinion I installed when I built it. both are like new. Slipper is cranked down all the way but it'll still slip if you bind it up hard. I see no point in 32p gears for anything but the most extreme brushless motor.

[Johnnysplits]

Originally Posted by Jus

I see no point in 32p gears for anything but the most extreme brushless motor.

On 6s