Need help with the basics to chassis setup


(Jake Reihl) #1

Hey all! I’m a total newbie and need some help on chassis setup basics. I just bought a used Praga Dragon Chassis that’s setup for LO206 Cup. I’ve been watching youtube videos and searching the forum here to help me get an idea as to how to adjust the chassis.

A little about myself; I’m a crew chief on a STL class RX7 in the SCCA Majors and know how to set up a chassis/suspension for a sports car. I’m a bit lost when it comes to karts though. I’ve been watching youtube videos and searching the forums here to help me understand better how to make adjustments and what said adjustments do. I’m still a bit lost though, especially when it comes to my chassis.

I’m not looking for anyone to hold my hand on this. I want to learn on my own, but I need a good place to start. Is there anywhere I can look to find how to make adjustments on my chassis? I’ve checked Praga’s website and not found too much. I’ll probably FB message the guy I bought the kart from for a little help, but I don’t want to be a bother to him either. I know that the kart is currently set up for the enduro at Road America at the moment.

Long story long… Are there any books or websites I access to get a better understanding of what I’m working with? Thanks all in advance!


(Davin Roberts Sturdivant) #2

Hey Jake,
Here is a thread of some chassis setup guides. Some of them, like the CRG one can help will some general concepts of how to set up a chassis. I’ll also add some links below once I find some articles for you. Once we get Kartpulse 2.0 up and running, we should probably do an article about this.

Also @tjkoyen would probably know of some good places too. I’m sure TJ would also recommend that the biggest thing to get used to kart setup is to make one change (like a narrow front width) drive it to see how it feel, and then slowly widen it, to get a better feeling for what the change does. (I struggle with that from time to time during practice days, and I’m trying to get better at remembering to just make incremental changes.)


(TJ Koyen) #3

Unfortunately there aren’t really a lot of great books per se on the topic. The best bet is to just ask on the forum here, as you’ve already done, great work! :+1:

My first advice since you’re a newbie is to just set the kart up totally neutral and work on driving it properly first. Any adjustments you make at the moment will be completely unnoticed by you just because you don’t have a feel for the kart yet.

The basic gist of it all, if you haven’t figured out yet, is trying to get the kart to roll freely through the corner. We don’t have a diff like a car does, so the solid axle is constantly scrubbing speed any time you’re turning. To get the kart to roll freely around the corner, you need to lift the inside rear wheel off the ground or unload it to the point that it isn’t scrubbing on the track surface anymore.

In the simplest of simple terms, you’re basically balancing the amount of weight jacking in the chassis through all the various adjustments. You’re tuning how fast the weight transfers and how much total transfer occurs. Too much transfer, and the kart will lift the inside rear but overload the outside rear and slide. Too little transfer, and the kart won’t lift the inside rear and will scrub speed off.

As far as the driving goes, remember that smooth is fast, and your body is the biggest piece of ballast in the whole setup, so your posture is very important.

I would start off by finding the Praga factory seat chart, to make sure your seat is in the right spot for your height/weight. And from there, just go out and turn some laps and get a feel for the limits of the kart. Once you’ve gotten relatively consistent in your lap times, then you can start to fiddle with the setup. The driver makes the difference in karting, as everything is usually very equal. Most of us running nationally don’t touch the setup too much, and are just making small tweaks to adjust as the grip goes down.

Feel free to ask questions and read a lot on forums like this and you’ll pick it up in no time!

Welcome! :beers:


(Don Westlie) #4

Jake, Sounds like you bought Brandon’s kart. I’m sure he would be more than willing to help with set up on it. I have a cheat sheet at home that I use with my Son on input vs output on set up changes. I’ll see if I can’t dig it up to share. I pulled it from online years ago. Maybe I can find it and post a link to it.

edit: found what I was looking for. it’s CRG, but pages 27,28,29 are what I’ve been using as tools. In the early years we’d go over it together when he came of the track. Now he either has it in his head what he wants right away or pulls the sheet out to show me what he wants. Good tool to keep handy once you get the driving part down. :+1:
http://www.southwestkarters.com/wp-content/uploads/2007/04/crg-setup-guide.pdf


(Jake Reihl) #5

Thanks everyone! I appreciate the help. I did buy Brandon’s kart. He was super helpful when I picked it up, and knew I’d have questions after I left. I really do need to get out and run some laps to get a feel for the kart. That will be coming within the next 2 weeks or so as I have some time off. I’ll post on this thread if I think of any more questions along the way. Thanks again!


(Nicholas Bushnell) #6

CRG suggest 1/16th to 1/8" front toe OUT for a starting point. Seriously? I never played with toe but will have to this time around since my new to me kart came disassembled.


(Eric Gunderson) #7

Toe is a great, quick adjustment to make! Almost all race cars have toe out built into their set-ups.

It’s funny, we used to run 1/8" toe out in circle track racing (also common setting on track day cars), and in karting it’s fairly common as well.


(TJ Koyen) #8

Almost all karts run 1-2mm toe-out on the stand. Pretty standard.


(Nicholas Bruno) #9

Is that 1-2mm toe out per side or total?


(James McMahon) #10

If we’re talking tow in mm (or any length vs deg) we also need to be sure we are measuring at the same distance from the spindle.


(Liam Sergeant) #11

Hey all, sorry for bringing back an old thread, it was the closest thing to what I was after.

What do you guys use to set your wheel alignment (in particular toe in/out)? I have a set of Kartech wheel alignment plates but they are slightly awkward to use with my brake rod and throttle cable in place. I saw some plates that look quite good designed to hang below the chassis I guess. Or am I better to save up and buy a laser system?

Also, I would be interested in more opinions on toe settings. The Arrow manual I have also lists 2mm tow out as the starting point. Does anyone run more than this?


(Liam Sergeant) #12

(TJ Koyen) #13

2mm toe out is pretty standard. We use a laser system, as it’s the easiest and quickest way to check it. That way if you want to see if something’s bent in the front end, you can just slap the lasers on the spindle, center the wheel, and see if they’re even. Literally takes 30 seconds. Plates are just more awkward to use.


(Liam Sergeant) #14

Thanks TJ.

I will save my dollars for now and try to buy right once!


(Noah Koenig) #15

2mm total or each side?:thinking:


(Aaron Hachmeister) #16

Toe is measured as the total difference between the distance of the fronts of the tires to the distance of the rear of the tires, so there should be a difference of 2 mm. For example, 1289mm front 1287mm rear (I pulled those out of nowhere don’t actually use those measurements.)


(Liam Sergeant) #17

That’s what I understood it to be as well, I just lost confidence to say haha. Measured from centre line of the tyre.


(James McMahon) #18

You’re good. I’d rather we keep relevant info on topic like this. We can always edit and or split later if needed.


(Davin Roberts Sturdivant) #19

Admin PSA

Never feel bad about bringing back an old thread. We probably would have joined the two anyway, so that the information would be easier to find in the future.

You did good. :wink: