Tire Hop

[rockwerks]

yes, my wheels are hopping when i am going up hill, when i said they wwere stuck, i ment that i was giving it throttle but it was not going anywere, it wanted to get the traction, but it sometimes just hops around. This was shile i was going up hill.
I know this is stupid, but what is anti-squat?
Is it how much the suspension can unload?
And what is droop? is it like sag?
Thanks for all the help, and for taking the time to answer my noobish questions!!
Oh yeah, raptorman, i thought you were giving me a hard time about the tire and wheel thing!:lol:

pics of your rig will really help us to help you

this is a very good info on basic suspension terminology and what does what

droop is the amount of suspension travel below ride height

http://home.tiscali.be/be067749/58/bug/print.htm

 

[Rc EnthuSiasTs]

Yeah i need to get a pic up, i am at school right now, but when i get home i will be sure to get a pic up.

 

[Reflection]

Oh yeah, raptorman, i thought you were giving me a hard time about the tire and wheel thing!:lol:

You thought right :lol:

 

[BigRedB2]

I googled the words. "An undesirable suspension characteristic in which a wheel (or several) moves up and down so violently that it actually leaves the ground. Wheel hop can be caused by many problems, including excessive unsprung weight, insufficient shock damping, or poor torsional axle control."

After reading some web definitions of "wheel hop" and knowing that you are having this problem going up hill i may have to rescend my earlier tip to get more weight on the wheels. actually...you need less weight "ON" the wheels and more "OVER" the wheels. Also lower the front of the truck.

When you hit the throttle, the weight of your truck transfers to the rear. when the weight transfers to the rear going uphill your rear axle acts like a fulcrum lifting the front end in the air. as the tires lose traction the truck stops and the weight again returns to the front of the truck, thus making the tires grab traction again and sending the weight back to the rear....thus continuing the cycle until the obsticle is over come.

The way this is dealt with in the 1:1 world is the hook the winch to the front axle and pull the nose of the truck down. this transfers the weight forward and tightens up the suspension so that it doesnt rebound as much.

In a scale world like RC crawling, moving battery weight to the front of the chassis out over the axle and using thicker fluid in the front shocks will help. Maybe using less foam in the front tire would help the tires be a little softer so they dont bounce as much.

 

[Rc EnthuSiasTs]

http://www.rcpics.net/media.php?searchstr=user:16251&trick=Any&type=Any&time=1164157676&search=search&limit=10
Got some pics, it is the first 4 pics of my album.
Bigred i still need to read your post, looks like some good info!

 

[Unholy]

Your problem is most likely the Stampede tires.
You are getting wheel spin and those tires do not grip.
Then the lugs start your hopping motion. "thumbsup"

 

[BigRedB2]

Extend your rear links and get better tires.

 

[EeePee]

Firstly, I'd try to lower the thing a tad, by moving the upper shock mount. That will change the link angles, and should alter your squat numbers, and make the rear tires spin more, than bounce. Give it a shot.

 

[Reflection]

......... When you hit the throttle, the weight of your truck transfers to the rear. when the weight transfers to the rear going uphill your rear axle acts like a fulcrum lifting the front end in the air. as the tires lose traction the truck stops and the weight again returns to the front of the truck, thus making the tires grab traction again and sending the weight back to the rear....thus continuing the cycle until the obsticle is over come.

This is where anti squat will help you. Set your links up for more anti squat and it'll climb better. The rear won't squat as much,therefore not lifting the front as much;-)

The way this is dealt with in the 1:1 world is the hook the winch to the front axle and pull the nose of the truck down. this transfers the weight forward and tightens up the suspension so that it doesnt rebound as much.

This is true,I understand all that. I honestly believe it's better to set your links up properly so you don't have to rely on the cable to climb. ;-)

 

[Rc EnthuSiasTs]

i am sorry, i know i should know these terms, but i am having a hard time understanding some of these ideas, i have an idea of what anti-squat is, but i dont really understand it, to me it sounds like it relates directly to sag and droop, but then again i dont truly know what those things mean either, i will search right now to try and figure what this suspension terminology means, but for now i would like to thank everyone for trying to help me figure out this problem, and of course, i would love to hear more feed back on any of this.
oh yeah, what do you guy's think of my trucks set up so far, how about the shocks, should i lay them down a little bit more, do the links look alright? Any input is valued, i am still new at this and am grasping to learn as much as i can from you more experienced guys!

 

[Reflection]

I'll try to help a little.

Anti squat. Depending on how you set your links,you can adjust how much or how little anti squat you have. What anti squat actually does? Ya know when you dump the clutch in a car and floor it,the rear end of the car will "squat" This inturn makes the front end light(less traction in a 4WD application or even a wheelie)

With various link mounting configurations,you can make the same car in the same situation squat when the throttle is applied, raise up when the throttle is applied or stay neutral when the throttle is applied.

Does this info help any?

Don't ask me how it does it,I just know it can be done. I'm not 100% positive but I believe it has some to do with the weight transfer. Depending on how the links are mounted to the chassis,it transfers the weight differently. I may be totally wrong or partially right,but this makes sence to me:lol: I know for a fact that theres alot more that plays into it besides this little bit,so don't take this as "all you need to know":lol: Just as something to think about.

I know Rockwerks is pretty slick with links and stuff,he'll steer ya in a pretty good direction.

 

[Rc EnthuSiasTs]

thanks raptorman for the reply, it does make sense.
Can you set the front of the car up to do certain things similar to that, like under acceleration have the front dip down? I know weight is not transfered to the front under accel, but if the back can be set up to raise a little, it seems maybe the front would be able to go down. Sorry if that made no sense.
One other question, what do you guys try to get at, a neutral position under accel, or do you try to have the least amount of anti,squat?
Thanks.:lol:

 

[EeePee]

Anti-squat in the rear: hit the throttle, rear of the truck goes up. You can have so much anti-squat that the shocks will try to keep extending themselves and try to actually lift the rear of the truck off the ground. Tires lose traction, gravity kicks in, truck comes back down, repeat. Rear tires are bouncing.

Squat in the rear: hit the throttle, rear of the truck goes down. Tires are being planted into the ground. Too much squat and after the tires have exceeded their total possible traction, they'll slip, and spin.

It's of my opinion that some squat is better, to aid in traction, but also because tire hop is near worthless.

Yes you can set the front of the truck with squat/anti-squat.

8)

 

[Reflection]

Like EeePee said,it can be done. It's just reversed,since the links are doing the opposite since they are backwards. They are on the front of the rig,but they are backwards from the rear links"thumbsup"

The way mines set up,I think:lol:,it's got a little squat. It can't be much though. With the power of my BIG outrunner,if I'm at a dead stop on flat ground and nail it,I can't even notice it squating. You gotta be quick though watching my truck. With a 45:1 final drive gear ratio.....it's fairly peppy:lol: