Steering linkage set up!

[Scott Hanisch]

Scott,
Maybe it is an illusion but that rt hand front axle looks like square tubing. Is it square or round?

I agree with Rob, keep the drag link set up on the kart, that is what it was set up with so I would keep it.

Also, Darts never had ackerman steering which causes one wheel to turn more than the other. McCulloch karts have it and most modern karts have it but Rupp didn't utilize it. Ackerman would require two equal tie rods, either mounted in two different positions on the steering shaft OR spindle arms angled in toward the center of the kart. Either one creates the ackerman effect which was made popular for indy cars.

I don't know if it really helps handling any on drifting karts like yours but ackerman does help even out tire wear.

My 2 cents.....Also, Rupp specifies a little bit of toe OUT in the front, try 1/16-1/8". It really helps the handling in my experience.


Hi there Scott. The front axle is round tubing and I believe it is %100 straight! So per factory lit, Rupp says run some toe out? Would have thought some toe in would be better!
Have fun and be safe,
Scott Kneisel

[Scott Hanisch]

Thanks to all who gave their input on the subject. I will have to check out some measurements and see if rupp designed the geometry into my particular kart. I will be using 4.10/3.50-5 sawtooth tires front and rear!

[Andy Symons]

Thanks, SteveO, for confirming what I've always wondered about. That the "poor man's Ackermann" you attribute to those who use negative toe (static) on karts and insist it works best overall are confused. Everyone has their own ideas and that's the basis for the intrique of racing mods for the masses, but as an old timer FEA guy, one never provides a rear wheel drive vehicle with static toe out. Not if you want to avoid a wander/hunting during straight line driving, that is, assuming you do a careful analysis of component wear before the FEA is done, and all is tight. Front wheel drive is a different ballgame.

I never considered that the guys who insist that static toe out is the best way to go might have been the guys running negative, 0 or essentially neutral, barely positive Ackermann and depending on a static toe out to facilitate useful turn in on turns! Thanks! Andy

[Tom Smith]

Max-Torque addressed the ackermann principle on their early karts with parallexed geometry which used two tie rods, a drag link, and a center idler arm for the tie rod's inboard pivot. In the pamphlet about their karts they acknowledge that a whole book could be written about the steering alone.
I've heard there was a Putt-nik kart that used an idler arm also.

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[steveohara]

Andy,

You know what they say... "whatever works". I have never driven any kind of kart or race car that worked better with toe out but there sure are a lot of people I know that claim to have benefitted from using it on a variety of machines. I don't doubt their claims but I will say that just because it works for a certain combination of machine and driver does not guarantee it will for a different combination.

I wonder how many others out there have ever stopped to consider that most karts have non-linear steering and the design really produces an effect that is opposite what you would want as a driver if you went to your engineer asking for improvement? On a kart the steering wheel vs wheel movement ratio is greatest closest to center and slows as the steering wheel is turned either way. Inuitively, one would think the driver would prefer the opposite with the steering rate slower near the center and quicker as you applied more steering input. That would make it easier to apply the correct small amount of steering input on the long fast corners and make it easier to "catch" the back end when the kart looses grip at the rear.
People that race full size cars without karting experience are always shocked by how "twitchy" a kart is when they drive one for the first time. One explanation is the motion ratio between the steering wheel and the front wheels is much different than what they feel in a race car with a rack and pinion steering setup.
Regards,
Steve O'Hara
PS... Tom.... nice kart! I've seen it many times and never noticed the trick steering setup. Maybe if I promise not to flip it over you'll let me drive it some time to see what that steering feels like

[Tom Smith]

Steve, normally the Nassau panel somewhat obscures the idler arm and you don't see it unless you poke your head below the panel. The steering is effortless and extremely precise, like the Bonanza. Just from memory I think in has 10 degrees KPI and 10 degrees caster. Oh yeah, and 0 bumpsteer.

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[steveohara]

Tom,

Looks like you were a little to short to reach the pedals!
Steve

[Tom Smith]

The little kid is Jeff Surwall.
http://motocrossactionmag.com/Main/News ... -6699.aspx

[Dick Teal]

Don is the guy with the crew cut. He traded me his Rupp "K" kart with a pair of Bombs for two new Fox box-mount karts for his two boys in 1969 or 70. Don was a pretty neat person and drove the wheels off of everything he got a chance to drive.

The picture is after I restored the kart in 1971.

Dick Teal

[Tom Smith]

Dick, I remember Mick Rupp sent Surwall a new white C-open Chaparral enduro Xmas present in 65. We went over to Max-Torque to look at it because it was the first one around. Somewhere I heard that Jim Hall wasn't too happy about them being called Chaparrals. I never saw another white one.
Rupp mini bikes were Max-Torque's largest account.


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