I just a Tony Kart 401RR with a TM R2 engine. The middle bearing on the rear axle is tight, but I was told it should be loose? Is that common/a standard setup for shifter karts or OTK karts? I’m struggling with grip in the rear end, not sure if it’s just the power/over driving a bit or if maybe the inside rear wheel isn’t lifting. I’m new to karting, only have 1 hour on the kart. I know I should just focus on my driving, but I’d rather get the kart set up better so I’m not sawing at the wheel as much.
I’d leave it tight, but either way loosening the middle bearing is going to be a relatively minor adjustment even for someone who’s been in shifters for a while. At 1 hour of seat time in a shifter and just getting into karting, the 3rd bearing it isn’t going to make a difference at all. As long as you have something even vaguely resembling a normal setup, just focus on putting in laps. No sense chasing tenths with chassis tuning when you have seconds to find with driving.
Thanks for the response. I know I still have a lot of time left in my driving. It just seems like there’s no way to keep the kart from oversteering a lot without being under the limit on high speed turns. Or maybe it’s normal for karts to handle like that with a little oversteer?
Here’s a video link if it helps. It’s mainly just the first two turns in the video, they’re the most high speed at the track.
Dang, for day 1 banging gears that’s pretty solid! You’ll be up to speed in no time. A couple of observations:
This track surface looks brand new. It’s not uncommon for new pavement with practically no rubber laid down to offer very low grip. That might be making your problem feel worse than it is.
A lot of the times you find yourself catching a slide here it’s because of a late turn in. Particularly in the first turn - both laps you just missed the apex a bit. A few other places it also seemed like your timing and lines were just a little off, or you tried carrying just a little too much speed into the corner and a slide was induced after trying to correct yourself. This is pretty normal when getting up to speed, as you get more time under your belt your brain and hands will start to catch up with everything happening around you. But I think this is honestly a pretty great start.
What tires and pressures are you running? Another quirk of newer asphalt is that you sometimes end up needing to jack the pressures up a bit.
Thanks. I had a TaG kart ~15-20 years ago that I took to NCMP a few times for practice and I’ve done sim racing for a year. I still feel like I’m just hanging on for my life in the shifter kart though. I’ll probably get a KT100 or TaG also just to focus more on being smooth.
You’re right, it’s a brand new track.
Thanks for the feedback! I see the late turn in now. I’m going to start working with a coach too just to avoid developing bad habits. But it’s still a struggle to just get the kart to consistently do what I want (turn at 1:12 in the video for example).
Tire pressures are around… 15psi hot (Evinco Reds, 55 degrees outside). I was running 18psi and think they got too hot, they started graining like the rubber was just peeling off.
Jake is dead on with everything he’s said so far. Just to be thorough, you may double check some setup stuff to ensure the seat is set to the recommended position, 2 sets of seat struts per side, front alignment is correct, and rear track width. Always run the third bearing tight. If too many of those are off then it may be working against you. The kart looks a little twitchy to me.
The biggest piece of the puzzle in KZ is throttle application. Too much too soon can totally throw the kart out of balance, annihilating your momentum as well as your tires. “Smooth is fast” applies to shifters just as much as any other category!
The rear width is set to 55". The seat has one strut on each side, the right side goes to the 3rd bearing though, which probably isn’t right. And the seat position is… I have no idea. I just put it in the only way I could make it fit. Does anyone know a shop or person in Vegas that would do it properly? I think acceleration and fastech don’t really do any service/work.
You’ll definitely want to confirm your seat position. That is one thing that could actually throw things off pretty substantially even for someone relatively new. There’s a pretty recent OTK seat position chart here which might help indicate whether or not you have things in the right ballpark. @ApexGRT is a regular on the forums here and runs an OTK shifter so maybe he can help also with that if you still have questions.
Someone here might also be able to point you to a shop in the area that could help, but it still might be worthwhile checking with fastech or acceleration anyway. Even if they don’t do a ton of service work in the area, they’d almost certainly know a few people who do. While you’re at it I’d also get that right side strut moved to the outermost cassette (you’ll probably have to do some bending to get it to fit around the exhaust) and I’d also work towards doubling up the struts on each side. 55” for rear track width is where you want to be there. While it’s still true that you are going to find a lot more time focusing on driving rather than chassis tuning, you’ll still want to make sure you have a chassis that’s at least pretty close to a baseline setup. Hope that helps!
Thank you! I’ll try to get the seat sorted out. I also used a Jecko seat which may be part of the issue. Going to switch to a Tillet T11t and use 2 struts. The Jecko has a lower back so there’s only room for 1 strut.
soft seat, neutral position with rear weight in the 57.5% range ideally. Seat even with bottom of frame. Stiff axle/hub combo, third bearing tight, full rear width, seat struts, low rear ride height, mxj wheels.
On to the driving… these things have more power than the tires can handle, so you need to drive in a way that has the bulk of your accelerating happening with the kart pointed straight. This means going deeper and rolling fast through the middle part of the corner, getting on the throttle later. You don’t drive it like a single speed kart, you don’t take the swoopy car lines.
Think of it more like a drag race and late braking contest on each straight, with a fast roll through the corners. As you get better at rolling the power on, you can get on it earlier. Getting the carb jetting to apply the power in a manageable way is also part of the puzzle, more so than any other class probably.
Obviously that isn’t to be taken as an “absolute”, every turn is different, but you get the idea.
Just want to second the comment that you will really want to take your kart to a pro shop to have the seat checked. I chased a weird handling issue in my otk shifter for a whole season, could never get it to work quite right and it probably developed some bad habits trying to drive around a weird issue all year, before eventually I learned my seat was mounted wrong and having the seat even a half inch off can make noticable impact on how the kart handles so now I always have my seats installed at a shop and then scale the kart also to make sure the seat and weight is good. I do basically everything else myself but the seats are very hard to get right without the proper tools and experience really counts too.
Fwiw on my otk shifter I had about the same setup as the guy above but ran two seat struts per side to the outside bearing, and I personally liked the double bolt longer rear hubs for tiny bit more exit bite, and I liked the mxc rims but mxj are fine also. I always ran medium height but our tracks are very low grip here.
Be sure your front bar bolts are nice and tight and the floor pan bolts are medium tight. My otk shifter was very sensitive to front end settings.
Imo 18psi is likely too high and kart will behave more consistently if the tires aren’t over heating
Experience is definitely a must, as attention to detail matters. The tools on the other hand don’t have to be complicated. I can’t tell you how many seats I’ve mounted simply using a 1x5 board and some clamps to secure the board below the frame rails. With all of the modern seats having flat bottoms, you then just need something heavy (a weight, couple of drills, gallon of water, etc.) to set in the seat in order to keep it flat and from easily moving.
From there it’s simple, though it can be time consuming to get it right:
measure (twice)
ensure that tabs are parallel to the seat surface, using a large adjustable wrench to bend them as needed
measure
drill straight so bolts are perfectly perpendicular to the seat surface
measure
tighten everything carefully so that the seat is not in a bind.
I second/third the comments about the importance of the seat position as well as @Muskabeatz comment’s that it’s very doable by yourself (though admittedly a PITA of sorts).
That said, if you’re not being scaled with the kart in order to find your seat position (e.g., the ‘full proper way’) then the only real choice is to set it to whatever the manufacture recommends for someone of your height and according to whatever the category of the kart is (in your case shifter). By going with the manufacturer recommended setting you can at least be sure to be in the general neighborhood. This thread imo is possibly the best place to find seat installation info.
Thanks for tagging that thread @calebgilbert I was looking for it to link it here…
If you’re new to karting, the best thing you can do would be go to your local (or whatever local is for you) kart shop and have them put the seat in for you. Installing the seat is a doable task, but you need to be shown the right way to do it. If you can learn it off of watching a youtube video I’d say go for it just because thats how I learned. Otherwise, go to the kart shop and have a professional do it. It is imperative that your seat is set up right or the kart is gonna handle like shit.
Additionally, @SamD used to run an OTK shifter with a jecko seat, so maybe he can point you in a direction of what to do.
The none shifter otk karts run the 3rd bearing loose. Not sure about the shifter, but imagine it would be tight. But its not going to solve the oversteer issue if its is bad as you say.
Get the correct stifness seat, correct measurements and scale the kart and go from there.
Also how old are the tyres? I run vega whites, the rears go after a day.
I’ve ran them for 3 days before. The rear was gone completely at that stage.
