Ultimate RC Home RC Forum RC Videos RC Photos RC Projects & others
Affiliate links:
Not a Member Yet? You're Missing Out!
Sign up in minutes for a free URC Network account and you'll be able to post in over 100+ forum categories, search over a decade of archived topics, exchange private messages with other members, upload pictures to the RC photo galleries, and much more!

Already have an account?
Sign in below!
Sign in:
Reply
Thread Tools
"Experienced user"
WOGGIES - 2.04.12, 3:08 pm Post #1: | Reply With Quote
Just wondering how people are gearing ? I have a 21t pinion and stock spur gear with the traxxas vxl 3500. What should I try if I want less acceleration? I can't really go full throttle or it will wheelie
"Experienced user"
WOGGIES - 2.04.12, 4:11 pm Post #2: | Reply With Quote
I believe I am at 21/87?
JroX's Avatar
"Experienced user"
JroX - 2.04.12, 5:16 pm Post #3: | Reply With Quote
Correct. Your stock spur is 87t. The stock pinion is 20t. If you're looking for less acceleration (higher top speed, less torque to stop wheelies) you're going to want to gear up (higher tooth pinion, lesser tooth spur).

Generally, your pinion will add more gradual changes as you experiment with different options. It's more of a fine tuning approach. Your changes with a lesser tooth spur will provide more dramatic results to your performance.

It might be a good idea to invest in a decent set of both pinions and spurs and see what you're liking the best both combination and performance-wise. Just remember to keep a close eye on your temps during running. Get yourself an infrared (laser) thermometer to monitor. You'll save yourself a lot of frustration and heartache with a $20 temp reader, you don't want to go frying your perfectly good components!

Anyway, back to gearing. Yeah, I have several spurs and pinions to play with, my pinions are 19, 20, 22, 24, 26, 28, and 30. Two tooth changes at a time are usually best for changing pinions.

As for my spurs, I have a collection of 72, 75, 81, and my stock 87 that came with my ECX Boost. Unfortunately ECX only provides the 87t spurs, if you want to change it, you will have to get the Associated spurs for the T4 and B4 vehicles.

For some reason I am getting away with a 75/30 combo with my 15t Dynamite motor. This has changed my drive ratio from 11.3ish (stock) to 6.5 (current) that's a pretty big slam in gearing. I don't know why, but it's working in my car and the temps are nice and cool all around. I DON'T recommend you doing this, but it's working for me, and my car flies on that brushed motor.. About 36-38 mph.

Just start with your pinion.. Go up 2 teeth - check your temps on your ESC and motor. If nice and cool (under 160 Fahrenheit) gear up two more teeth until you are either getting the speed you want OR getting close to thermal limitations.. If you're up to a 30t pinion and still have room to play around with, change your spur to a lower tooth and start over with your pinion to be safe (Go down a few teeth and work your way up as you experiment). Keep in mind the less teeth on the spur, the smaller diameter it will have and you will be limiting your pinion options because lesser tooth pinions are usually smaller diameter and it may leave you too big of a gap to meet the two gears to mesh them. I had to go thru this the hard way..

Have fun, and watch those temps!

Cheers
(Last edited by JroX : 2.04.12 at 5:29 pm)
60% of the time, it works every time.
kingkong559's Avatar
"For her pleasure user"
kingkong559 - 2.04.12, 7:27 pm Post #4: | Reply With Quote
Always start with stock gearing and go from there.. It will wheelie whether you like it or not. It takes throttle control to maintain wheelies. You can get a wheelie bar to prevent your body from contacting the ground.
Automotive/Motorcycle enthusiast
49ERS
Gone fishing on the weekend. Don't bother me.

Opinions are like @holes, everyone has one.
"Experienced user"
WOGGIES - 2.05.12, 3:35 am Post #5: | Reply With Quote
Actually, i have a 23T pinion right now, I am going to try a 25t.
indy34096's Avatar
"Shake n' Bake"
indy34096 - 2.05.12, 5:29 am Post #6: | Reply With Quote
Stock gearing is 19/87 on the Circuit. I don't know if it's maybe 20t on the boost or not.
Associated B4.1 FT, Associated RC10 Classic, ProBoat Impulse 26
He passed me, so I rammed him. -- Rocket Rex Staten
MOPAR OR NO CAR!!!
Larry's Performance R/C's Frequent
"Experienced user"
WOGGIES - 2.05.12, 6:32 am Post #7: | Reply With Quote
Yes, it is 20/87 on the torment. I currently have a 23T pinion on there. Motor and ESC do not get hot at all. Going go try the 25T pinion.
Ratrodsuzuki's Avatar
"bring me a shrubbery"
Ratrodsuzuki - 2.05.12, 6:48 am Post #8: | Reply With Quote
I believe a stock vxl slash is geared 23/86 and they seem a bit heavier than a torment. 25/87 is a good start.
dustyhubsrc.com
☆breaking rc cars since 2001☆

"Experienced user"
WOGGIES - 2.05.12, 7:24 am Post #9: | Reply With Quote
Thanks rat.

So If i get the 25 and still want to gear up more. Should I go to a 27T pinion, or start gearing down the spur?

Does it matter if you increase the pinion or decrease the spur, as long as they both fit?
Ratrodsuzuki's Avatar
"bring me a shrubbery"
Ratrodsuzuki - 2.05.12, 9:41 am Post #10: | Reply With Quote
I guess it will depend on the room available. If there is room for the bigger pinion, gopher it. Otherwise, smaller spur. But if you have to go smaller spur, go back to the 23 tooth pinion and try that. Like jrox stated ealrier. It might be better just to adjust the slipper a bit.
dustyhubsrc.com
☆breaking rc cars since 2001☆

Reply
Thread Tools


All times are GMT -8. The time now is 6:28 am.


Featuring: Ultimate Tamiya, Traxxas Slash forum, Slash 4x4 forum, Ultimate RC forums

Original content & design copyright ©2000 - 2013, Bamidele O. Shangobunmi & the Ultimate RC Network. Privacy policy
Manufacturer/vendor images, names, & trademarks are copyrights of their lawful owners & used with permission and/or within Fair Use guidelines.

Lego fan? Check out JANG's LEGO blog and LEGO videos on YouTube