Weight savings options for your kart?

So my son went from running cadet last season, and being about 5# heavy, which wasnt a huge concern, to jr lite, with a full size chassis, and is now 35 pounds heavy.

Obviously a huge part is him being a physically big kid, but are there any obvious spots to trim a few pounds off a kart?

I have magnesium rims coming to replace the aluminum rims, i might swap the 8.5L fuel tank for a 3.5L off a cadet kart. Could do mini gears possibly.

Any other thoughts?

What class and what type of kart? Photos would help.

Hes in Briggs Jr Lite, class weight is 265 pounds, he’s running a Kosmic STV450 chassis.

Don’t have any pics of it built up right now.

Any chance he can step up to the next class that’s heavier? Depending on the organization you can get a waiver to step up fairly easy.

I did ask about that, our club has jr heavy, which they prefer to be 12 to 15, and since he just turned 11 before this season started, they said they would likely deny it based on his age. Their advice was to use this season to get used to the bigger kart, and move to Jr heavy next year.

I’d balk at that, being at a 35 pound disadvantage should be plenty reason to step up. Being only 1 year shy on age it should be no issue as long as he’s competent and not going to be dangerous which sounds like shouldn’t be issue. What insurance does your track use?

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Remove decal kit, smaller fuel tank, lightweight hardware.

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507 bodywork, titanium steering shaft, nerfs and bumper hoops, carbon floorpan, no graphics, cut off middle bearing hanger, cut off rear bar spuds, no Mychron, small tank, switch to MCP brakes with a 1/8" rotor…


Or, sell the OTK and buy an American Chassis because we build them light cause most of us are heavier than the 110# Italians…


35 lbs is about 20% of a kart’s weight. Move up a class. You’d have to run a cadet kart and then start sawing steel off wherever you could to get it down on weight, replace as much steel as you can with wood, etc, and you still wouldn’t be close.

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If there were any dealers of American chassis around here, id consider it, but there isnt, and i have half a dozen OTK dealers i can get parts from.

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I inquired and was told the club already rejected a request from a kid to go straight from cadet to Jr heavy.

Then you need to switch engines/classes to something that’ll allow you to make weight.

Cut off the end of long bolts.

Buy castle nuts, drill the bolts, use cotter-pins or safety wire.

Instead of split lock washers, go to star washers or nylon locking nuts (or castle, drill, cotter those too).

Eliminate washers where safe to do so.

Lose the torsion bars and learn to adjust driving style and chassis tuning without.

Run minimum oil.

Carbon fiber everything.

Aluminum everything.

Shortest hoses and wiring. Smaller diameter hoses, smaller gauge wiring.

Cut and/or gun drill pedals.

No excess cable ends.

Strip paint.

Cut excess worm clamp ends.

35 lbs is a lot though.

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Sadly not much of an option. Have to wait until next year to move to jr lite, no clubs locally that run VLR, and ROK GP jr is also a minimum of 12 years old, so no go there either. Probably just have to deal with it this season.

Do as much as you can and then just treat it like a learning season if you are still way overweight. It’ll be like swinging a weighted bat and next season you’ll be stronger because of it.

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Thats what im seeing as the best bet this year. I’d be more concerned if i felt he was at his max and the extra weight was the only thing holding him back, but realistically he’s still leaving time on the table, i think I’ll see what i can do to drop 5 pounds off the chassis and also get him working on his fitness more, which is also holding him back on long days at the track. Hopefully by the end of the season his driving and fitness will bridge the gap a bit and next season he’ll be on even keel.

I have that overweight problem. I’ve been replacing steel with titanium, aluminum and plastic where I can. Drilling lightening holes in some metal supports.

30lbs is a lot of weight. Feel for you this season. But next year the kid is gonna be FAST.

Thats the hope! He’s currently running right at weight for jr heavy, but has the briggs slide for jr lite. Next year at the same basic weight but more power, he should be competitive.