I just picked up a brand new seat for my son’s kart, his previous seat was used with a million holes in it. I don’t want to mess up a nice new seat, and was hoping someone would have a good guide for seat mounting and positioning.
Thanks
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You tube.
If you didn’t take to old one out yet and your kid like the position, measure it first both sides before removing it, put the new one in the same place.
Thanks, I’ll check YouTube and see what I can find. His old seat is long gone, and he’s grown quite a bit since last season, so definitely going to need to mess with the seat and pedals for him.
What kart? Most major brands have a seat placement guide.
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One tip I can give is that sitting a sheet of wood or cardboard under the chassis rails while on the stand can make it easier to manage. Also placing a little weight in the seat to keep it upright, a hammer for example.
@Richard_Jacques is there a particular video you are thinking of on YT?
Here’s one from the kart360 fella:
Like James said. I stick a couple of 2x4’s under the kart front to back then place a few rear sprockets between the seat and boards to adjust for height. The bottom of the seat is usually flat do it will sit there while you measure and mark the holes.
It’s a parolin cadet chassis, I’ll start with them and see if I can find a guide.
Thanks for the video, thats a great start.
- SCALE YOUR KART
- DO NOT place too much faith in standard chassis placement guides.
- DO NOT ASSUME an OEM seat dimension means the same on a Tillet seat
Your own body shape can result in radically different weight distribution than the official seat placement guide is meant to attain. For example, years of skipping leg day in the gym resulted in me being a bit “top heavy”. Either that or I have heavy rocks in my head. If I set at OTK Size 4 seat exactly per their mounting guide, I end up with Front 39.5% and Rear 60.5%. Not good. For me, every 1 cm forward on the seat shifts front/rear distribution about 1.1% to Front. To get 42.5% on the front with tank 1/2 full, I had to mount the Size 4 seat a full 27.5 mm more forward than the OTK chart recommends.
I can not even use a Tillet T11 seat at all. The shape of the Tillet T11 results in the seat hitting the mounting tabs on my older style OTK chassis with no spacer at all before I get it far enough forward. The “bucket” of the OTK seat is quite bit shorter, creating more space to move the seat forward. Also, the distance from the seat front edge to the back of the seat on a Tillet T11 is about 1.2 cm greater than the OEM OTK seat (also consistent with the OTK “bucket” being shorter). So if you mount a Tillet T11 per the OTK chart, your BODY ends up 12mm farther back than the OTK chart intends. The seats are NOT the same. Plus there are fiberglass seats…and there is variance from seat to seat.
So…SCALE YOUR KART. Weight Dist is what matters…not dimensions. The dimensions are meant to achieve a certain distribution for an assumed body characteristic. This may not be you.
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This is the correct answer.
No harm in using scales if you have access to a good set, but I wouldn’t waste my money on buying a set of my own. I agree that the manufacturer starting point is not a one size fits all, but it does give you enough info that when coupled with detailed measurements can help you find the right spot for any seat. From there, it’s going to take some testing and trial & error to find the optimal position. Also keep in mind that you may have to move the seat based on track conditions!
As mentioned above, not all seats are created equal, but with detailed measurements you can get an idea of the differences between each, and adjust accordingly. I use up to eight measurements when mounting a seat, and track everything via a google doc (below). If you’re going to use just one dimension then I would stress “dimension D” as the most important, as it takes away most of the variability from seat to seat. There will be some differences based on the depth of the ridge in the center of the seat.
Get a good baseline, try different things, and let the stopwatch be the judge.
I can second that!
The first time I mounted a new seat in my 2nd hand kart, I did based on the previous owners position with a slight shift rearward for my added height. Balance was way off. I had too much weight over the rear axle, kart would not release off the corners and even so far as to hop in several. The previous seat was and OTK, the new seat was a Tillett. The shapes and stiffness’ were different as well as the overall size. I ended up going back to the Tillett suggestions for D above and the kart settled down dramatically. A & B overall lengths were almost irrelevant, as the larger seat stuck out more in the front, but the difference from A to B was very close for side to side distribution.
I did not pony up for the fancy jigs available and opted for a homemade version using 2 x 4s, a straight edge and a sliding square I already had. When I went to scale it a few weeks later, it was nearly perfect (less than 0.5% off target). It was definitely worth taking the time to do it right.
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Its good to scale the kart if you can, as it serves as future reference and it will indicate if the chassis is twisted (if you don’t have a 4 wheel laser gauge). In the end be prepared to move the seat at the track and put more holes in your pristine $200 seat.
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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?
Regarding the comment about scaling the kart, how is this done exactly? I presume you have to drill holes before you can sit in it to scale it? Once you’ve got 8mm holes in it, it seems sketchy to move it any less than say 15mm to avoid overlap, which is a pretty big adjustment. I’d appreciate a dumbed down version of how to install without turning your seat into swiss cheese. Thanks!
I have always just put the seat in and seen if I am comfortable/does it look right. Then, I just tune on the kart a bit and see if it needs to move for balance sake and usually I am on the money. Every now and again I need to move it.
I dont run chassis with much support, I do things my own way anyways.
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There is no way to scale the whole setup without installing the seat, that’s why you see those guides, which will help you get very close to optimal…but over time you will start accumulating seats so you can do whatever test you want with the older seat. Alternatively, you can get a used ugly old seat for cheap and do tests with that
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You can Swiss cheese a seat up pretty good and it will still be fine if you use big washers when you get your final mounting point. I’ve run seats that looked like they were shot with a Tommy gun for like two seasons with no issues.
Mount it where the placement guide tells you to start, and tweak from there if you need to get your weight distribution better or get more comfortable. Most guys are going to move their seat once or twice to tune anyway, so having 2 or 3 sets of holes isn’t the end of the world.
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What I don’t see in the manufacture’s placement guide is positioning side to side. Should I be looking for equal wieght left to right when scaling with the driver in the seat? Should I shift the seat to the non engine side to compensate for the wieght of the engine. I use an extra large T-11 seat and to get equal wieght left and right I have to bend outboard the engine side seat rear mount by about 35mm. If I don’t do this I end up about 15 pounds more on the non engine side. My question to the experts is: Am I better off bending the crap out of the seat mount or living with more weight on the left side?