Last reviewed: August 3, 2026 · By the RaceYear team
Short answer: Cross weight — also called wedge or bite — is the right-front corner weight plus the left-rear corner weight, divided by the car’s total weight, expressed as a percentage. On an oval, more cross weight generally tightens the car and less frees it up. You set it by raising and lowering corners with the car sitting on four level scale pads.
Key takeaways
Setup-direction note: Adjustment effects described here are directions to test from a stated baseline, not universal guarantees. Response varies with chassis and suspension geometry, tire construction and pressure range, track surface, corner phase, driver input, and what else changed at the same time. Confirm against your chassis builder, the tire manufacturer, the current rulebook, and your own scales and lap times.
Ask ten racers in the pits what cross weight is and you’ll get ten answers, about four of which are wrong. It’s the fastest, cheapest adjustment on a circle-track car — a few turns of a jack bolt and the whole balance moves — which is exactly why so many people chase it in the dark and end up somewhere they can’t get back from. Here’s the plain version, with nothing but a level floor, four pads, and a pen.
Cross weight is the percentage of your car’s total weight carried by two diagonally opposite tires: the right front and the left rear. Racers also call it wedge or bite, and on an oval it’s the main knob for moving the car between tight and loose.
Those two corners get grouped because a car on four tires is a wobbly table. Push one corner down and the diagonal corner picks up load with it. Grassroots Motorsports draws the line at 50 percent: above that, “the car has wedge,” and below that, “the car has reverse wedge” (Grassroots Motorsports). A road-race car wants to live near 50 so it behaves the same turning both ways. A car that only turns left does not.
Add the right-front corner weight to the left-rear corner weight, then divide by the car’s total weight. Multiply by 100 and that’s your cross weight percentage.
Grassroots states it exactly that way: “add the RF weight to the LR weight and divide the sum by the total weight of the car.” iRacing’s chassis column runs the same math — the two tires added together, divided by the total weight of the car (iRacing).
A worked example on a dirt Modified that scaled 2,400 pounds with the driver in it:
| Measurement | Math | Result |
|---|---|---|
| Corner weights | LF 560, RF 520, LR 700, RR 620 | 2,400 lb total |
| Cross weight | (RF 520 + LR 700) ÷ 2,400 | 50.8% |
| Left side | (LF 560 + LR 700) ÷ 2,400 | 52.5% |
| Nose (front) | (LF 560 + RF 520) ÷ 2,400 | 45.0% |
One warning, because it’ll save you an argument at the pit table. There’s a version of this floating around that takes the right-front percentage and the left-rear percentage and averages the two. That’s different math — run it on the numbers above and you get about 25 percent, roughly half the real answer, and it won’t match anybody else’s sheet or any builder’s baseline. Add the two weights, divide by the total.
You scale a car on four level pads, in full race trim, with the suspension settled before you read anything. Almost every bad cross weight number comes from skipping one of these steps, not from bad scales.
It’s fussy work, and the fussiness is the point. A cross weight taken on an unlevel floor with the bar hooked up is worse than no number at all, because you’ll trust it. For the full garage walkthrough — leveling cheap pads on an uneven floor, fuel and driver conventions, and which four numbers to write down — see How to Scale a Race Car at Home.
Raising a corner adds weight to that corner and to the corner diagonally across from it. Lowering a corner does the opposite. Grassroots puts it directly: raise a corner and “the weight on that corner will increase, as will the weight on the diagonally opposite corner”; lower it and “that corner will lose weight as will the diagonally opposite corner.”
That’s the whole mechanism. There’s no magic in a weight jack — you’re changing which diagonal pair of tires carries more of the car.
| Goal | Raise (turn in) | Lower (turn out) |
|---|---|---|
| Add cross weight | Right front and left rear | Left front and right rear |
| Take cross weight out | Left front and right rear | Right front and left rear |
Longacre says it the same way: “If you want to add cross weight put a turn in the right front and left rear and take a turn out of the left front and right rear.” Speedway Motors gives the mirror image for a car over 50 percent — take weight out of the right front and left rear, or add turns to the left front and right rear (Speedway Motors).
Which is also the answer to “does changing ride height change cross weight?” Yes, every time — same bolt, same turn. Split the change across all four and the car keeps sitting where it was: iRacing puts it as “proper crossweight settings are made by adjusting all four, and doing so will keep ride heights consistent while changing only crossweight.” Crank on one corner and you’ve moved two variables with one turn.
The general rule on a left-turn oval is that more cross weight tightens the car and less frees it up. But name the corner phase before you turn anything, because that rule is a starting direction, not a law.
Speedway Motors frames the back of the car as bite: “bite is the weight of the left rear in relation to the right rear,” and “adding weight to the left rear tends to tighten the car, while adding weight to the right rear tends to loosen the car.” That’s the diagonal talking — load the left rear and you’ve added cross.
Now the honest part most articles skip. iRacing’s chassis column warns that “while the normal ‘more crossweight = tighter’ is a guideline, it is by no means a law,” and that cross weight “by itself, is not an indication of whether or not a car will be tight or loose.” It works in combination with spring rates, nose weight, left-side weight, and the racetrack.
So make the driver tell you where first. Speedway’s setup guide asks the right questions: “Where on the track was the car tight or loose? Was it tight or loose on throttle or off throttle?” (Speedway Motors). A car that’s tight in and loose off isn’t a cross weight problem — that’s shocks, bar, or driver, and wedge just moves the misery from one end of the corner to the other.
Same complaint all the way through? Cross is a great first move. Complaint changes phase to phase? Look elsewhere. Either way, make one change and drive it — Speedway recommends “making only one adjustment each time you race.”
Cross weight doesn’t live alone. It gets set against your left-side percentage and your nose weight, which is why two cars in the same class can run very different cross numbers and both be right.
iRacing spells out the trade: “Typically, a higher nose weight will need a lower crossweight to keep the car going around the track, while a lower nose weight will need a higher crossweight.” Cars carrying more left-side weight can generally get away with more cross weight, too.
So copying somebody else’s number is a trap — their nose weight may be nothing like yours. Move lead and your cross weight moves with it, so readjust ride heights any time you shift ballast (Longacre Racing). Check the rulebook too: plenty of classes tech minimum weight and left-side percentage, and the tech inspection line is a bad place to find out you’re outside it.
A cross weight change you didn’t write down is a change you can’t undo. Grassroots is specific about what to keep: “always record the cross-weights and ride heights for reference at the race track in case changes are needed.” One without the other is half a setup. Log all of this together every time the car goes on the scales:
Speedway’s setup article says it as plainly as it can be said: “You can never keep enough records.” A binder and a pen do this fine. So does a spreadsheet. The only failure mode is not doing it.
There isn’t a universal number, and anyone who hands you one without asking about your car is guessing. iRacing notes that oval racing cars “can vary wildly from car to car within the same class of racing.” Start from your chassis builder’s baseline for your car and track, confirm your class rules, then move off it in small logged steps.
Usually, but not always. More cross generally tightens a left-turn oval car and less frees it up, which is why it’s the first thing most racers reach for. But cross weight works alongside spring rates, nose weight, left-side weight, and track conditions, so it isn’t a standalone predictor. Diagnose the corner phase first.
Yes, for a real number. Cross weight is a relationship between four corner weights, so you need all four readings at once on level pads. Plenty of racers share a set within a team or borrow one at the track. Without scales you can still track jack bolt turns and ride heights, but you don’t have a percentage.
Every time. The jack bolt or spring collar that sets ride height at a corner is the same one that moves load onto that corner and its diagonal partner. To change cross weight without changing how the car sits, split the adjustment across all four corners. Change ride height for any other reason and you need to re-scale before you race it.
It does, but the goal is different. A car that turns both directions generally wants cross weight near 50 percent so it behaves the same left and right — Grassroots calls anything above that wedge and anything below it reverse wedge. A circle-track car deliberately runs off 50 because it only turns one way.
You can absolutely do all of this by hand. Scales, a level floor, a tape measure, and a binder get you every number in this post, and plenty of championships have been won exactly that way. The measuring isn’t the hard part. Doing the math the same way every night, remembering what you turned six weeks ago, and finding the sheet from the night the car was perfect — that’s the job RaceNight was built for:
Log your scale numbers and your cross weight every single night in RaceNight — it works offline, and every plan starts with a 14-day free trial. Starting on paper tonight? Grab the free printable Spring Smash setup sheets before you unload. New to scales entirely? Start with the garage procedure in How to Scale a Race Car at Home, then build out the rest of the sheet with our guide to the race car setup sheet, and sharpen your diagnosis with loose vs. tight before you turn another jack bolt. Cross weight is only half of what puts bite in the car. The other half is geometry — four-link setup on a dirt track. Racing at 1/10th scale instead? The identical diagonal-weight physics, worked out for an RC chassis and battery pack, are in RC corner weight and battery placement.
Ran across a term here you’d have to look up? They’re all defined in the RaceYear racing glossary.
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