Evolution of a Suspension Kart

[Russell ATV]

Ok, I am in mid build of a twin Clone suspension Kart. The idea for my designs has been to create a lightwieght but highly capable off road kart. There has been a disapperance of the simple light kart, either going toward rigid racers, or massive buggies.

Here is how it began:

Light Kart 001 - My first totally homemade kart. One wheel drive, leaf spring steel suspension, 2 stroke 4HP Tecumseh. One wheel drive sucks. It weighted 52 lbs

Tadpol Quad 001 - shortened two wheel drive in a tadpol arrangement. Clone power, it was quick, but the wheel arrangement made it quick to steer and white knuckle to drive around 40MPH. Weighed 85lbs.

Kart 008 - One last attempt at a two stroke. This time, a pocket bike engine with a pipe. It was fairly week off the line and only had about 500 RPM on the pipe when it had some power. 2 wheel drive with leaf spring rear and dual front high temper spring steel. Engine was crap. Weighed 43lbs

Kart 002 - Now we are getting somewhere. Dual high temper spring steel suspension front and back. Clone power, 2 wheel drive. China parts for seat, steering wheel, tires, brakes, drive, and bearings. Either opposite wheels on cinder blocks. Measured 60 degrees of roll front axle to rear, 6" of independant wheel travel. 76lbs

IMG 0575 - without 200lb me, the front wheel is 11" off the ground. I have a 6:1 ration on the drive, with the governor by passed. Perfect for some serious off-roading.

Pictures of the twin suspension Kart coming........

 

[ed1380]

dang those are nice.

the 2 stroke engines look tiny. cant expect much from that size

 

[kibble]

Interesting design with the leaf springs!

 

[rgvkid]

I love um! Great engineering. So many questions....

1.Do you have any close ups on the leaf springs and mounts?
2.Does it bottom out?
3 Do you have to arch the springs at all and what type of material are the springs?
4. Does it sway when turning?
5. Where did you get the tires?
6. Last one, how much did you spend on the last one minus engine.


I love the flex on the cinder block. Now image if it were 4 wheel drive with dual engines. I would love to make a mini Crawler but haven't been able to figure out the engineering for the front steer with live axles. I do metal work and i have all the material in shop but what liked to get some tips before begining.

Thanks, Great Job!

 

[Kenny_McCormic]

Very neat! Thanks for the ideas! Where did you get the spring steel stock? Got dimensions?

 

[Russell ATV]

Designing with the Spring steel means starting your design around it. You cannot weld to it, and drilling it can be a pain. It has taken me about a year to perfect the thickness, material, and design implementation, and there is still improvement needed.

Since I am planning to productize this, I cannot reveal all of the secret sauce. However, Leaf Spring steel is incredibly common, and robust. It is a bit heavy compared to the high temper steel, but a good starting point. Look for 1/4 to 3/8" thickness for a single beam suspension. The spring compliance comes from length, so it needs to be as long as possible from the wheel to the frame. At least a foot. Bolt the spring steel to the frame.

Russ Barrow
Russell ATV

 

[Russ2251]

I cannot reveal all of the secret sauce.

That's kind of against everything we are all about here.
Maybe I should keep all my secrets and 40 + years experience to myself?
Being thanked well over 100 times does more for me than $$$.

“Whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.”
Antonie van Leeuwenhoek (1632-1723)

I apologize for the off topic rant and is not meant to be an attack, but rather an observation.
I follow your posts with great interest!!!

 

[jr dragster T]

Thank's Russ make that 101 thanks now! And even if you did reveal all of the "secret sauce" it doesnt matter because your not realy a profesional bussiness making mucho bucks off your spring steel suspension desihn. Just my $0.02.

 

[Kenny_McCormic]

Thank's Russ make that 101 thanks now! And even if you did reveal all of the "secret sauce" it doesnt matter because your not realy a profesional bussiness making mucho bucks off your spring steel suspension desihn. Just my $0.02.

Even if he becomes that we wont be buying it, this site(and the people on it) is all about building and restoring.

 

[BradenM]

We aren't exactly going to steal your stake in the market.

 

[rgvkid]

Good luck on your kart venture then.

 

[Russell ATV]

Once the rants get going, they come in waves apparently.

I try to assist people with any knowledge I have. I did so even with the dimemsional data I provided on the leaf spring material. Copying designs is not what makes America great, we are about the endevour of improving our environment and making our place in it. With my design, I am attempting to do both. I am at a starting point in my business, and soliciting the opinions of those who know something about what they like and dislike about this hobby.

I know this is not a place for the sale of a new product, and you do not see me selling it here do you. However, the low cost parts I have found through my research my help this kind of audiance.

As for what this forum is about, it certainly is not a place for short-cut knowledge. I have learned more about design through doing-it-myself than having someone give me the info. That is part of learning. I am more than willing to help anyone try this type of design out and impart the knowledge that has made my particular design work. But based on what you want, the material, and expertise you have, I will help you with YOUR design.

Let's not turn into a bunch of no imagination, lazy, let someone else do the work people. Create something of your own, or restore with your own vision, whichever might be the case.

If you have no hesitation to share what you have worked hard to gain (monetarily or knowledge), share it openly, but don't lecture me for showing restraint. Work a decade or two in corperate america and tell me about trust.

Russ Barrow
Russell ATV

 

[Russell ATV]

So...., back on point.

The twin engine build. Using the same suspension design and beefing up the rear axle frame, I am close to completing the twin engine design. Since this design allows me to seperate the frame from the rear drive section, I am reusing a proven high speed frame from a previous revision. The Kingpin angle on the front axle is nearly 45 degress. I have to build in a significant amount of self centering to offset the suspensions compliance.

Twin Kart 1 has the rear axle and suspension points. I will drive the rear axle via 2 40 teeth #40 sprockets. With the clutch sprocket of 10 teeth, with both engines I should be able to get around 50MPH without too much trouble (nerves willing).

Twin Kart 2 has the frame and rear axle mating

Twin Kart 3 has the engine mounts done, engines mounted, and dual throttle lines connected. I have synced them fairly close.

The true purpose of this kart is to measure any desernable difference between the two engine, but running them one at a time. The Red/White engine is supposed to be more powerful (torque and HP), and the Yellow is considered top notch in many of the facing forums. Running both engines will be fun.

Don't worry, I will share which one I find to be more powerful (if any difference at all). Helping other people make their designs better is what I am happy to provide...........

Russ Barrow
Russell ATV

 

[Scorch3]

Wait to run both engines at once in true twin engine cart fashion, don't they need to identical or at least very close to it?

 

[ed1380]

i think theyll run one at a time so he can see which one is better and then maybe run 2 of the better engines

 

[Russ2251]

don't they need to identical

Exactly right. One engine will most certainly outperform the other.
The weaker of the 2 will pull down the other.
I went to great lengths to match my engines up (work in process).
It's difficult enough to synchronize carbs.
Even gasket thickness or a mis-torqued head bolt can change the total picture.
In a sense, they are blueprinted to each other.

 

[thgrahamjr]

Looks good, that double engine setup ARC has looks awesome.

 

[Russell ATV]

Running both engines will be just for fun, but yes, the main purpose is to validate Torque differences, so I have chosen a high gearing (small drive sprocket).

Assuming I can get the throttles close (and this is just as difficult with two of the same engines), the 6.5HP clones are all within 5-10% of each other, which is almost about the same standard deviation as two idenical manufactured engines, lot to lot.

As mentioned, the seat of the pants and timed tests will reveal their similiarities and differences. Adjustments can then be made to either as needed to match them up for fun.

Russ Barrow
Russell ATV

 

[Scorch3]

I'd like to see some video of this thing in action. It would be cool to see how well it pulls since it weighs so little (for a suspension kart) but mostly i'd like to see that suspension flexing.

Quick grab the cam and go burn through a nice bumpy trail!

 

[Russell ATV]

I'd like to see some video of this thing in action. It would be cool to see how well it pulls since it weighs so little (for a suspension kart) but mostly i'd like to see that suspension flexing.

Quick grab the cam and go burn through a nice bumpy trail!

I have been thinking about this lately. I have a good camera to capture the video, but what I would like to do is mount the camera to the frame and position it so that you can see the terrain and wheels going at it.

I have the single engine kart done, so that one can be done sooner versus later. The twin engine is still about a week or so from being complete.

Russ Barrow
Russell ATV