Mounting a new seat and figured I’d double check against the chart since I was in a rush before my last race and just went for it moving the seat back an 1" Are we in agreement this is the current OTK seat placement guide with measurements being further back then the old chart? Assuming a Tillet T11 will be similar in measurements to OTK seat.
This is the correct chart for the newest models. You’ll know if it applies to your model, because if you try to set the seat in this spot on an older kart, it’ll hit the bend on the right-hand seat stay. On newer models they moved that bend/stay so the seat can move further back.
I’ve got mine set between this chart and the old chart for my 2020 kart and it feels balanced nicely. I know a few Masters guys who are running slightly forward from where this chart recommends too.
Perfect! Just wanted to confirm. It’s the first thing that pops up on an image search, but it’s from Koene which I’ve never heard of.
Unless OTK seats have changed recently, I’ve always found the measurements to be about 1-1.5cm shorter if using a Tillett, due to slight differences in the seat shape.
Essentially, the Tillett seats are slightly longer.
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Gotcha. I’ve got a new-ish OTK seat somewhere. I’ll put them together and see if the leg area is longer/shorter.
Koene are a big OTK team.
I should clarify that by “newer models” I mean 2021+. On my 2020 I hit the seat strut when trying to mount it according to this chart.
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I’ll second that this is the correct chart for “newer” karts but add that I’m running the seat on my '21 closer to the old settings than the new ones. This chart became a huge point confusion last season after I found the updated settings and had already mounted my seat exactly where it was on my '18 (slightly back of recommended settings for the older karts).
The thing scales 43/57 where I’ve got it which is where the kart feels like it drives the best so I’m not moving it back unless I really start to find issues I can’t tune around.
For everyone’s reference. ‘21 chassis. I got my Tillet T11 size ML back to 645 right side 650 left side, parallel and flush to the bottom frame rails. There is maybe an 1/8” gap to the small tube. No more room to slide any further back so I’m not sure where the over 650mm measurements are coming from or possible.
Edit: might just be down to the Tillet vs OTK and maybe the measurements are for a smaller seat?
In my ‘21 it was a similar experience. I think I may have gotten my Tillett back a hair further but no way to achieve the 665/670 measurements. This season I switched back to an OTK size 3 and the furthest back I could get was also 655mm with the bottom close to flush with the tubes. I’d have to think you’d need a size 2 or smaller to go further back. I’m right at 180CM tall so fall in-between on measurements. I’ve also found myself moving the seat further forward 10mm in warm weather anyway.
Has anyone scaled a kart using this chart? The weights must be closer to 40/60% than the usual 43/57%.
Mine was 42.5% front weight with the seat mounted as mentioned above. You’re going to have to scale for yourself though as everyone weighs different amounts and is built differently.
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Like Chris said depends on the person. I’m 5’9 175-180 lbs and pretty muscular. I scale in at 42% front for reference. Works for me, but I like a less reactive front end.
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Does anyone have the newer recomended seat posistions from OTK for the 2022 Racer 401RR OK-KZ (1045mm wheel base)?
Also does anyone have the newer OTK 2022 chassis setup guide?
Hi All,
Resurrecting older post. We just picked up our first OTK (2022) and are in process of mounting seat. Senior 206, size 1 seat, 172cm tall (skinny kid). When we attempt to set at the dimensions per the new chart, the seat braces end up ahead of the seat. Would need some sort of bracket to offset rearward but it just doesn’t seem right. We’re planning on mounting up per older chart, scaling and then go from there. Curious if anybody else has experienced the same.
Something isn’t jiving here. From the bottom right picture, the seat looks overly rotated clockwise in the chassis. Getting the measurements right is one thing, but sometimes you need to take a step back and ensure the seat is square in the chassis.
How much room do you have on the engine side strut? It should be around a 1/8" to 1/2" gap.
Also, I think the measurements are based on a size 2 seat so you may need to make the measurements A & B smaller for the smaller seat.
Here are some samples of the seat I mounted last week. Size 3. I didn’t follow the measurement from the top of the axle to the letter as it would crash the small engine side strut tube. Also since every brand has a different seat shape I think measuring from the axle to the spine of the seat is a better way to measure.
Scaled the kart tonight. Just for reference a ‘22 401rr with a Rotax and no fuel weighs in right at 180lbs. With me, 10lbs of fuel, and 10lbs of lead on the left side of the seat I’m right at Rotax Masters weight of 385lbs. 58.5% in the rear.
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Thanks Clayton. For reference, how tall a driver was the seat set up for? Had a big work week so didn’t touch but am mounting up today. I think you’re right about the dimensions being based on a seat bigger than size 1. I wish we only needed 10lbs. Will be adding ~80 to get to 365.
I’m probably 5’9” or 10”. Since you will be placing so much lead you’ll have a bit of freedom in seat placement since you can move weight around the seat for balance. I would recommend mounting the seat. Go turn some laps and have your son feel out the balance in the kart. If it needs more front end bite place weights towards the front and vice versa for rear grip.
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Some of the tonykart seat diagrams vary for different wheel base chassis’s.