dirt road track kart setup

RD1970

Member
very new to karts looking for a base general starting point setup for a dirt road course style track. The track consist of mostly right hand turns with a few lefts. looking for things like what tire size and spacing on the axle how to set up the alignment. and the weight. What kind of seat set up should I go with? Clutching things like that. Again I'm brand new to this and just looking for advice. I'm 6'3" 200# thank you in advance.
 
Location ?
Generally a rr set-up should fit the bill .
. Sit up seat . Treads or slicks . Both frt the same bothr rear the same .
11/5/5 frt 12 /8/5 or 11.5 / 7/ 5.
Tires there abouts wether 5 or 6 inch wheels .
 
I'm in Ohio just a back yard track.
I'm not sure what a rr setup is I'm sorry like I said I'm all new to this.
they run slick tires.
thank you for you input so taller wider tires in the rear? should the rear width be narrower then the front width?
 
Road race setup.
No . Id say close to even . If possible.
Biggest thing is getting it going and hit the track . Probably dont want too wide of a tire in the rear . Its got too turn.
 
that is a good question I'm not sure what it is to be honest just a used kart. I figured setup wise in general would be the same no matter the brand?
 
Definitely not the same. Post some pictures of the chassis and someone should be able to help. Try to tip it up and lean it against the wall and get a good picture of the frame from underneath and also where the front spindles are attached. I’m not a frame guru, but this is the information needed to determine what you have.
 
An older chassis would probably be better if its a dirt kart .
Otherwise a sprint kart is what you need .
 
Ok been away awhile but trying to get back at it. This is the kart I'm playing with it's a crg. Trying to set this up for what you guys call a sprint track but on dirt.
 

Attachments

  • Screenshot_20230207-105019_Gallery.jpg
    Screenshot_20230207-105019_Gallery.jpg
    78 KB · Views: 62
  • Screenshot_20230207-105038_Gallery.jpg
    Screenshot_20230207-105038_Gallery.jpg
    73.7 KB · Views: 62
Wow, that looks too good to be running on dirt! LOL!

Judging by the radiator and four wheel brakes I'm going to guess that was originally set up as a shifter kart (125cc MX 2 stroke with transmission attached). You didn't mention what you're going to power it with, but if it's a backyard track I'm going to guess a Chinese 4 cycle of some kind? Shifter kart chassis are pretty stiff to handle the horsepower of the 125, and you'll need to free yours up to make it work.

We've run a few races with our sprint chassis on a dirt oval. I'm certainly no authority on what you're trying to do but I think some of the things we've learned will apply. Loosen the bolts holding the inner right bearing carrier on the rear axle so it can float in the mount, or if you happen to take the axle out, take that bearing off and leave it off. The length of the rear wheel hubs affects the stiffness of the axle - longer hubs = more stiffness - and yours has some really long hubs. That looks like a 40mm axle in your kart, they're pretty common in that era European karts. Measure it to be sure. I'd check on ebay for someone selling a selection of used 40mm hubs of different lengths. Start with the shortest one. If your kart seems loose in the rear switch to a longer one. Also, sliding the rear wheels out takes away grip, in gives you more grip. We use this adjustment all the time to adjust to changing track conditions. This is a pretty sensitive adjustment, just 1/4" in or out will make a noticeable difference. Front wheel spacing is the opposite of the rear wheels - moving them out gives more grip, in takes grip away. This is also a sensitive adjustment, 1/8" either way will make a difference. There should be a bunch of wheel spacers on your spindles to set the spacing where you want it. As for a starting point for your setup, I have no idea! If you can figure out the exact model of your CRG chassis you can probably find a starting setup for it on line. It will be for sprint racing, but we've found that our pavement setup wasn't very off to run on dirt. If you can't find that info, I'd start with 50/50 side to side weight balance and 42% of total weight on the front. Set the front wheels at 1/16" toe out, and have someone else measure it while you're sitting in the kart because your body weight flexing the chassis will make it change. Set the wheel spacing about mid-way both front and rear and see how it works, then adjust accordingly. For tires, we found that Vega Whites work pretty good - 7.10 x 5 on the rear and 4.50 x 5 on the front, with tire pressures in the 3 to 5 psi range. They're already a soft compound, but a generous application of Goat P makes them even softer if you want to mess with that stuff.

My apologies for the VERY LONG post! I'm retired and have all kinds of time in the morning while I drink my coffee, so this happens from time to time!
 
Wow, that looks too good to be running on dirt! LOL!

Judging by the radiator and four wheel brakes I'm going to guess that was originally set up as a shifter kart (125cc MX 2 stroke with transmission attached). You didn't mention what you're going to power it with, but if it's a backyard track I'm going to guess a Chinese 4 cycle of some kind? Shifter kart chassis are pretty stiff to handle the horsepower of the 125, and you'll need to free yours up to make it work.

We've run a few races with our sprint chassis on a dirt oval. I'm certainly no authority on what you're trying to do but I think some of the things we've learned will apply. Loosen the bolts holding the inner right bearing carrier on the rear axle so it can float in the mount, or if you happen to take the axle out, take that bearing off and leave it off. The length of the rear wheel hubs affects the stiffness of the axle - longer hubs = more stiffness - and yours has some really long hubs. That looks like a 40mm axle in your kart, they're pretty common in that era European karts. Measure it to be sure. I'd check on ebay for someone selling a selection of used 40mm hubs of different lengths. Start with the shortest one. If your kart seems loose in the rear switch to a longer one. Also, sliding the rear wheels out takes away grip, in gives you more grip. We use this adjustment all the time to adjust to changing track conditions. This is a pretty sensitive adjustment, just 1/4" in or out will make a noticeable difference. Front wheel spacing is the opposite of the rear wheels - moving them out gives more grip, in takes grip away. This is also a sensitive adjustment, 1/8" either way will make a difference. There should be a bunch of wheel spacers on your spindles to set the spacing where you want it. As for a starting point for your setup, I have no idea! If you can figure out the exact model of your CRG chassis you can probably find a starting setup for it on line. It will be for sprint racing, but we've found that our pavement setup wasn't very off to run on dirt. If you can't find that info, I'd start with 50/50 side to side weight balance and 42% of total weight on the front. Set the front wheels at 1/16" toe out, and have someone else measure it while you're sitting in the kart because your body weight flexing the chassis will make it change. Set the wheel spacing about mid-way both front and rear and see how it works, then adjust accordingly. For tires, we found that Vega Whites work pretty good - 7.10 x 5 on the rear and 4.50 x 5 on the front, with tire pressures in the 3 to 5 psi range. They're already a soft compound, but a generous application of Goat P makes them even softer if you want to mess with that stuff.

My apologies for the VERY LONG post! I'm retired and have all kinds of time in the morning while I drink my coffee, so this happens from time to time!
Don't apologize for the long reply that is a lot of helpful information I'm not sure I understand all of it but I'm learning thank you. Yes it is a shifter kart I would love to keep it that way but the engine for one is out of my price range. The guys I run with all run predator 212 engines. I will get online and look for smaller hubs. as far as the tires the guys I run with all use 6" dirt tires like Burris? they are super wide front and rear, but beings the track is like a dirt road course I'm not sure that set up is ideal but I have no idea? I am trying to find some one local that will let me use there scales to set up the weight but we'll see I guess.
 
My opinion Tire width is going to be your key component .
Agree super wide might not be the best , its probably got metric pattern hubs so 6" american wheels wont fit due too the wheel stud patten .
5" rain tires should be easily sourced .
 
My opinion Tire width is going to be your key component .
Agree super wide might not be the best , its probably got metric pattern hubs so 6" American wheels wont fit due too the wheel stud pattern .
5" rain tires should be easily sourced .
apparently you can adapt the metric to American with adapters? and I thought of rain tires but the guys I will be running with say they don't allow them because they tear up the track. Someone else said 6" will give you more ground clearance for the dirt but that doesn't make sense to me. if the tire height is the same the hole in the middle wouldn't matter?
 
Ok so they are not running treads .
Overall diameter is the only thing that affects ride height with a tire .
I have used the adapters myself .
Might be hard to find .
There kinda fifty fifty .
 
Comet sells the hubs with American pattern. Then you could buy the same diameter rims as the guys you race with.
 
Ok so they are not running treads .
Overall diameter is the only thing that affects ride height with a tire .
I have used the adapters myself .
Might be hard to find .
There kinda fifty fifty .
thank you Yes they run slick tires. and thats exactly what I was thinking so the wheels wouldnt matter. i live 20 min from bmi and I seen they have them. but trying to cut as much cost as I can I may see what I can find used and stay with the 5" just depends I guess on what I come acrossed
 
For the dirt I was also told to remove the front brakes and the torsion rod on the front of the cart? Is this something I should do?
 
If the front wheels lock up it won't steer . so that depends on if its got a proportioning bar and your driving style .
torsion bar i would leave on as well and try it first .
 
Ok guys started tearing this thing apart. I'm taking the crg front hubs off because apparently only crg wheels fit them. So I am removing the front brakes. The new hubs I got don't have mounting for them but will make it so I can run normal metric wheels or adapt easier to American. My question now is how wide do I make the front and how narrow do I make the rear? I have spacers for the front hubs I can move them in or out about an inch? I mocked it up with a rear wheel for dirt road course I was thinking I want wider tires but are these to much? The rear I know brettm57 said I need shorter hubs but there are so many choices not sure what I should get? He also mentioned removing the right inner bearing on the rear axle ? I have to take the axle off to change the sprocket carrier so do I just leave that bearing out? It has 2 on the right side so just run the outer? ill attach some pics of what I got. First one is how it was with crg hub and brakes, second one is with new hub spaced 3/4 out with a rear wheel/tire , third is the rear axle bearings and hub on it now
 

Attachments

  • Screenshot_20230222-115100_Gallery.jpg
    Screenshot_20230222-115100_Gallery.jpg
    74.5 KB · Views: 17
  • Screenshot_20230222-115111_Gallery.jpg
    Screenshot_20230222-115111_Gallery.jpg
    74 KB · Views: 16
  • Screenshot_20230222-115122_Gallery.jpg
    Screenshot_20230222-115122_Gallery.jpg
    70.4 KB · Views: 16
Back
Top