Otk 4 stroke vs 2 stroke chassis

So my 12 year old has been running an exprit 1010 nordix chassis and is now growing out of it so I purchase a tony kart 401 full size. I notice that both chassis have only the one seat mount welded on the chassis with the adjustable seat bar next to the engine. Speaking with some other people who are running the same chassis they seem to like the 2 stroke version as it has both seat bars welded to the chassis. Any benifit to one vs the other

My Margay Has an Adjustable side seat mount, generally for 4 strokes you aren’t producing enough torque and power to necessitate a welded seat mount. Welded one would give you a more stiff feel but also can crack. Why they do them differently and weld one and bolt on the other is unknown to me. Generally if your not happy with the balance you could add a seat stay for Rigidity.

Thanks, my younger son was using a margay k3 ignite. Now I’m going to put him in the exprit. Time to do some testing come spring…

I’m a little confused. All the OTK chassis have welded seat stays. The 401 and the 450 both come with welded on both sides.

I wasn’t familiar with the 4 stroke tonykart but this is what I thought he was referring to.

I’m sure your familiar with pretty much every chassis lol, but You can see there is 4 bolts that clamp to the chassis allowing the seat mount to be moved left and right as well as bolts in the bar itself allowing It to go up and down

lol, I’m not familiar with all of them, but i am familiar with the 3 in this discussion. To the best of my knowledge, the Ignite K3 is the only one of these that has the bolt on strut. The 401 and 450 OTK versions both use welded on struts.

Not a great picture, but gets the point across:

I’ve never seen an OTK with a bolt on seat strut unless someone cut one off.


I was trying to find a pic but no luck. I do believe the first year, possibly second also, of the 450 was a 40mm and removable right side strut. 2017 18 maybe???

Was called STVK at that time

1 Like

Thanks, Don. I always wondered what the STVK was. I am only familiar with 2020 and 2021 STV450s.

Found one.

I recently saw someone with one of those bolt seat stays. Can’t remember what he was running, I just remember thinking, “I’ve never seen that one before.”

I guess it does make sense, for seat adjustments that don’t require a heavy mallet, lol.

I used a bolt on stay when I cracked the compkart seat strut off. Was rigid enough for a podium. :sunglasses:

Replaced this sus fella:

And then I threw away the chassis. :joy:

1 Like

Well, I’ll be damned.


Actually now that I’m thinking out it, my daughters Arrow cadet kart also has that adjustable arm thing-o-ma-giggy.

I think her chassis is circa 1990’s?

Yes, they are very popular on other karts, as well. Coyote used them forever, lots of American manufacturers do. In fact, they are still used almost exclusively in the offset world, as well. I jsut never saw an OTK kart with one. Learn something new every day.

1 Like

I believe pre 2019 OTK, had the moveable seat bar on the right side. That chassis came with a 40mm axle. After then they came in with welded seat bars. My 2020 chassis has the weld in bar. I would steer clear of the moveable bar version as they do tend to move. I was never a fan of chassis with that setup.

The 401r vs the stv450(4 stroke)
401r has 25mm spindle vs 17mm spindle
401r has different brake disk and caliper
401r has slanted rear cross member vs stv450 straight bar.
Both are 30mm chassis
I believe the rest of the frame geometry is the same.
I am curious myself to try the 401r for 4 stroke.