I ride a KZ chassis CRG RR 2023 and no matter what I do I don’t have the same grip as the KR
Have you experienced this yourself or are you making a comparison based upon others results?
It’s based on more drivers switching to the KR chassis and their lap times improving…
Maybe the CRG RR chassis is fast when there is a lot of grip on the road
Can you test one? Might be that the chassis is more suited but it could be something else. Dominant team responsible for most kart sales in series?
My observation over time is this is usually the case. It’s the team/tuners that make the difference, along with drivers of course.
I’d say go test one. Make sure this isnt a case of FOMO.
My guess is that any major chassis can be tuned to work. Could just be a case of the team on KR has setup figured out.
My racing pal Tanguy had a real bad experience being stuck in CRG that he couldn’t get in the window when racing euro tour stuff back in the day. So, it could also be that CRG is just weird. This seems really low probability, though.
I think the KR 2 is a combination between 30/32mm and my CRG is 32mm.
Constantly slides especially in the long corners and the tires finish in 20 laps. I run warm at 0.85 pressure. I have tried with a front plastic bar. every adjustment of the front. I have not tried only changing the rear axle. I feel the kart is very unstable and at the same time there is traction in the slow U-turns. We drive with hard green vega tires.
Another chassis isn’t going to make it for you, the Road Rebel has been out there for a long time and have had great success as any other chassis.
First of all I think it is a question about wrong pressures, I’d start with 0.55bar cold pressure and test.
For stability in long corners you can widen the front more and have the rear 140mm measured at the outer part of the rim.
Is it oversteering instantly or how is it behaving?
I have tried widening the front in every way and it has no effect. I’m 140 in the back. I turn slightly and the kart immediately becomes unstable
If it is working well in slow corners but is sliding in fast corners you probably need to reduce weight jacking a bit. I would be narrowing the front or removing caster or something.
The kart is lifting and rotating well in slow corners where there is less load but when the load increases you are overworking the tire.
Do you think 30/32mm is a better option on tracks with a little less grip. We drive with green vega hard tires
Then I would suggest you to reduce caster. People tend to drive with reduced caster on this chassis since it is very front positive
I’ll interject this for a sec, as lately I tried few different KZ chassis in 30mm, 31.75mm, 32mm, mixed 30/32 and I can tell you…none of that matters. Sure, within the same brand it makes a difference (e.g. 30 vs 32 or 30 vs 30/32) but if you are comparing two different brands, the difference in metal, geometry and few other things is massively more important than tube diameter. My 30/32 IPK is way stiffer than a 32 CRG torsion/wise (and the CRG is already a stiff one), we almost flipped the bench to take a couple of mm of twist out of it. Conversely a 30mm Birel is close in stiffness, as they use very hard metal (in fact, you very rarely see anybody running a 32mm birel). All that to say focusing on diameters only can be very deceiving.
TJ and Lucas giving you very good pointers to work with the platform you have. Another route would be reaching out to a team that runs CRG close to you, book a day of tests with them and let them help you sort the basics. Every brand has its own quirks when it comes to baseline setup (e.g. rake or no rake, mid-height vs slammed all the way down, a particular axle etc) and it will save you a lot of time to get that sorted out by people who run that specific brand, on those specific tires, in similar tracks/conditions
Great point Andy, I was going to say this as well. Tubing diameter is only part of the story. One brand’s 30mm kart might be stiffer than another’s 30/32.
As others have suggested, I’d try reducing caster first. I’ve also run as low as .5 bar cold with Vega greens in KZ, you may need to reduce pressures a bit as has also been suggested. I’ve also had some luck with a softer axle in my 32mm compkart (so grain of salt here, different chassis will tune differently, but this is another very front positive chassis). I’d also make sure your rear ride height is low and your weight is more rearward.
In my relatively limited experience with Vega greens with KZ, I’ve found the first heat cycle to be the only time the tire feels decent and then performance drop off can be pretty severe following that, especially if you’re overdriving and sliding the kart around through the fast corners. I’ve found that reduced caster to keep the rear flat in the fast stuff helps at the expense of some rotation in the slow corners, but the trade off seems worth it just with keeping the tires alive. You may also need to be more deliberate about backing off a touch following qualifying just to preserve your rubber for the day.
All good advice here. I’d reaffirm checking with a CRG team to see how they recommend tuning. From there it’s really going to come down to testing and tweaking until you get the balance right. Don’t be afraid to gradually work towards extreme ends of the tuning window. I run a different brand chassis, but one that is 32mm and very front positive; at my last race event I had 3 degrees caster removed from standard, which is a ton.
At times you may find that the balance doesn’t feel the way you want it, but the kart is still fast. At the end of the day the stopwatch never lies.
Stopwatch never lies, totally correct. I’ve had setups that felt fast and secure but slow as hell.
When I had setups that felt very on the edge I’ve always been the fastest.
Personally I run a mixed 30/32mm energy, quite stiff. No front bar in, neutral caster and one dot negative camber. Normal front width, 140cm rear and one seat stay each side with greyhound rs3 seat (t11vg equivalent)
Working as a threat, testing days are for testing.
I’m talking about KR specifically. Does anyone know if their frames are softer? Maybe that helps on tracks with less rubber…