Technical > Roo Man's Room

Wheelie bar, second-guessing myself a bit here..

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janjon:
So, single wheel, one lower, two upper tubes. 1" x .094 MS DOM tubing. 5 feet out from the mounting tabs on a 150" WB FED. 1/2"-20 threaded rod ends at the ends of the upper tubes, one end right-hand thread, the other left-hand. This to be able to center the wheel in the tracks of the more forward tires and adjust height also. So the uppers need to be able to be turned independently and together to do this. The single lower bar similarly has the same right-hand rod end mounted to tabs at the front. Problem is, set up like this, you can grab the caster and tweak it a bit one way and the other. And looks like to me, if the car launched a little bit crooked, this steering input would be a bad thing, not a good thing. There has been mention of tying the upper bars together (somehow), and using a McKinney adjuster on the lower bar for height adjustment only, but I still don't have a clear picture of how that whole setup would look. Please see the attached picture, and anyone's thoughts and opinions are welcome.
Thanks, John.
Well he;;, the pic.s too big, try to snedit tomorrow.

GlennLever:
My Roo Man built wheelie bar has two fixed upper tubes and one adjustable lower tube for adjusting the wheel height.

wideopen231:
Mine same as Glenn's. Not sure what tube he has. Im going with 1.250x.058 wall. I was going 1.125 but was because of material I thought I would have,now that I have to buy I'm stepping up little. Might hit Roo Man up on the 1" thing.Maybe if shorter bars ,if going long (mine are 6') I would be worried about them at 1" tube.Jusy my thoughts.sure Rooman will have better input.

rooman:
I usually use 1.125 x .058 or 1.25 for the upper bars and 1.125 for the major part of the lower with 1" for the slider to allow the bar to be pinned up higher for towing around the pits. I use a weld clevis at the chassis attachment points and at the bottom I use the McKinney wheel bracket which also has a welded mount for the bar. When I build the bar I run a string down the centerline of the car to locate the wheel. The clevis that I use at the top mount is made for a 1" tube so I weld it to a short stub and then slip that into the 1.25. That allows me to line the wheel up on the string by sliding the main tube on the stub and once it is aligned then I weld the slip joint. On some cars which hit the bar hard I add a cross member about half way between the chassis and the wheel to keep the top tubes from bowing out under load.
My desktop 'puter at the shop has had a modem failure and the laptop that I am using does not have all of my photos loaded on to it so I am unable to post photos at this time. Glenn may have some of the installation on his car.

Roo

Cajuninjector:
As far as the wheelie bar steering you at the launch, it can be a major deal. We fought this for a few rounds one time. A friend showed me how to center the wheelie bar wheel with the slicks and the launches were back straight as an arrow. Comp Eliminator class will give you a first hand look into interesting wheelie bar designs and how they work. Pretty cool when they launch at 9000 rpm. Lol

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