sunco1

iTrader: (29)

I've been watching the nats in PA all day and couldn't help but notice how many people like to throw their cars sideways over jumps. Do you guys do this? Is it purely for style or is their really an increase in speed through the air? How do you do this? Sometimes I get lucky and pull one off, but normally when I race I concentrate on just making the jumps!

scracer68

iTrader: (9)

Whipping or scrubbing a jump lets you hit the jump faster and lower and if done right can deffinately be faster over certain jumps. You need to really know the track and the jumps and your car very well to do this consistantly.

Jerm13

iTrader: (36)

it also helps you set the car up for the on comming turn by shifting the weight. not very difficult to do but very difficult to do consistantly. And you have to have a pretty good set-up on your car. if the suspension is too stiff it will flip on landing, too soft and it absorbs the weight transfer and you get nothing.

asc6000

iTrader: (15)

what a load of malarky, you can in no way do a motocross style scrub, mechanically physically impossible, like getting tv from a radio. Yes you can "whip" and yes you can fly in a way that has benefits ... but, no motox scrub.

tc5 man

Me no one im not a "pro driver " but do race in a pro truggy class at times not always . I have to much other things to worry about when jumping lol.

But ive noticed any guys do that at the tracks ive been to .

Its really a pro driver a "paid driver" kind of thing ive noticed watching videos.

Im not sure hows its possible with a rc car the only thing i can think of is that you have to turn the front wheels full lock a little before you land.

scracer68

iTrader: (9)

You're the only one I've seen mention "motocross" scrub in here. When I said whip or scrub all I was saying was hit the jump in a way you can scrub speed and stay lower and it is "mechanically physically" possible.

R.Shackleford

iTrader: (4)

To answer your question yes I do "whip" the car when it is advantageous.

What we are doing is setting up for a corner after a jump. When you throw the car off the jump in the direction of the next corner, the car wants to roll to the opposite direction of the corner (which will result in the car rolling upon landing, as the car is already angled in the roll axis toward the outside of the corner). So to counteract this you have to steer the wheels the opposite direction of the corner in the air. This will "lean" the car into the corner upon landing. If any of you have ridden street motorcycles you have no doubt felt the gyroscopic effect used in counter steering. When you turn the bars slightly to the left the bike wants to lean right. Simple physics really. Same principle at work on our r/c cars. Really good drivers can also "catch" the car in the air if it begins to roll. To do this you need to steer into the direction of roll. In other words if the car is rolling to the right, steer right and it will cause the car to roll back left. It is not really that hard (if you're good), it just takes practice. Once you get it figured out you can really control how the car flies and lands.

As for Mr. you can't motocross style scrub. Obviously a 4 wheeled r/c car can't get the lean angle coming off of the jump, but the concept is exactly the same. You turn one direction coming off the jump (it is just way more exaggerated on a dirt bike) and then once in the air, crank the wheels (or wheel) in the opposite direction to use the gyroscopic forces to correct the angle. It just so happens that on a dirt bike you can lean the bike to counteract/redirect the rebound forces of the suspension, thus "keeping it low". Also in addition to being able to lean a dirt bike, you have this dynamic (moveable) weight (the rider), which comprises about 40% of the weight of the bike/rider combo. Being able to throw this weight around also has a big effect on the flight characteristics of the bike.

Go to youtube and search 775k50QWlTM The video is local hot shoe Austin Blair getting down on the new layout at Nor-cal. Pause the video at 0:44 and look at how cranked the front wheels are (in the direction of the turn). Then go to 0:45-0:46 and see how his wheels are cranked the complete opposite direction.

OldGuydust

iTrader: (18)

Muahahahaaaa.... I likey!! ^^^

I used to love doing this with my hotshot in 86'... 4wd makes it so much more.. haha..

Davidka

iTrader: (85)

All correct but to make sure readers really understand the differece, the biggest cause/effect of the moto scrub is that the rider can effectively shrink the height of the jump by the amount that he can lean the bike over. Done correctly, it is breaking traction of both tires and laying the bike down in the face of the jump. It's known as the "Bubba scrub" but James Stewart by no means invented it, he just did it in such an exaggerated manner that he was able to seize a bigger advantage with the technique. Others had to learn to do it like him to keep on pace. You can find video of Bubba doing this where his wheels have left the ground 1-3ft before the top of the jump and the side of the bike is just clearing the lip. How he gathers the bike back after this "controlled crash" is the magic.

The "whip" we do with cars is purely a directional control. Because the car can't be leaned over on the face of the jump the loft from the jump will be more or less the same.

I do like to emply a different scrub when I can make it work. I approach the jump at high speed and chop the throttle (or even brake on the face) to shorten the flight. It's hard to do on some jumps but when it works it's a great way to pass.

sunco1

iTrader: (29)

Good advice everyone I think ill start experimenting with different this and see what happens. I believe that is the best way to learn; trial by error so to speak.

Ah yes the "bubba scrub"-the one thing Stewart can do without wrecking himself

scracer68

iTrader: (9)

You can scrub speed and height off of some jumps by making the car break traction going up the jump face and turning the car sideways then correct it once it leaves the face of the jump.

CR0SS

iTrader: (5)

With a scrub like you see in moto the riders are not scrubbing speed. A true scrub lowers your flight path and reduces the distance you jump. You see this when a rider hits a jumps and is passed by another rider who scrubs mid air who is also flying 4' lower. When a motocross rider hits a jump and does a scrub they have to scrub or they would overshoot the jump. The 75' jump on the track I work/ride on if I hit it at the speed of the guys that scrub it I would overshoot the jump by at least 20' if not more. They land right at the top of the landing. As you learn to scrub one thing that makes it intimidating is you have to start hitting the jumps faster. If you hit a jump at the same speed you did before and scrub you would case the jump. Casing when trying to scrub is not to much fun because with a scrub the front of the bike drops in the air and casing front wheel first is not a good feeling.

So doing a scrub with a RC car I do not see how that is possible. Yes you can whip and setup the car for what is after the jump.

Davidka

iTrader: (85)

You can scrub speed and energy, sure, but it's not the same as what the moto guys are doing. They are scrubbing height/distance while keeping speed.

http://www.youtube.com/watch?v=WYytyij1wII

vw addict

iTrader: (38)

Whips, please. I do backflips over the triple while leading the A.

madweazl

iTrader: (12)

Only time I make adjustments mid air are when I come off wrong or I need to work a different line to get around traffic. We do have a 90 degree step up on the current layout that I have to make corrections on 7 times out of 10 attempts, about 1/2 of those attempts will get me what I'm after, a couple more close enough, and I'll screw up a couple. A few layouts back, there was a jump that you would have to "whip" every lap if you wanted to get through the section quickly.