Traction, grip, bite—call it what you want, it is the only thing bonding your tires to the racing surface, and it determines everything on the racetrack. The two most popular components of traction are forward grip and side grip. Forward grip defines how much traction you have when accelerating in a forward direction, and helps to determine things such as how quickly you can accelerate out of a turn, or if you'll be able to clear a huge triple with a short run-up. Side grip is the amount of traction available when a tire experiences side loading, such as through a turn.

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Issue 168 (November 2009) - Words: Jeff Eveleigh

It becomes very difficult to discuss forward grip on its own because, other than with a starting grid, it is almost always a component of corner exit. That being said, we're going to break down and explain how to adjust for forward grip within your chassis. Much of this article will tackle physics and theories, but remember that there are so many factors to chassis setup that no amount of theory beats good old track time So, learn how your vehicle is supposed to react to certain changes, and then go try some of them yourself to see how they work with your setup, driving style and track conditions.


Tires should be the largest single factor when it comes to any traction consideration. This holds true for forward grip as well. Given that tires are so important, we snagged ourselves an expert to interrogate: pro driver Scott Hughes of Pro-Line fame sat down with us for a bit and chatted rubber, tread, traction and gazebos!

When choosing a tire to maximize forward grip, you only really need to concentrate on the tread design. Different tire compounds don't play a huge role in determining forward grip and are chosen based on specific track, dirt, and wear conditions (we'll be doing an article on tire compounds in an upcoming issue). Tread design is the master of accelerating hard in a straight line and Hughes gave us the goods on why the shapes are the way they are on many tires. When looking to maximize forward grip, you want a tread design that offers horizontal bars from left to right, such as those on a Pro-Line Bow-Tie. Longer cross bar designs act almost like a paddle, scooping the dirt and providing unmatched forward grip.

Another major factor of tread design that affects forward grip is the density of the spikes in the center of the tire. Tires such as Pro-Line's Revolver and Caliber pay more attention to the center treads. As the tire expands under heavy acceleration, the only contact patch is that of the center spikes. More center spikes offer more forward grip, and longer tire wear when your finger is heavy on the throttle. Also keep in mind that any tire tread choices that increase forward grip will also greatly increase your vehicle's braking ability in the forward direction.

As a final note on tires Hughes gave us a list of the most typical track surfaces and the top two Pro-Line tires, starting with the one that offers the most forward-grip. Remember that this stuff is never carved in stone, but can be used as a strong guideline to start.

Surface Type
Hard, packed and wet - Caliber, hole shot
Blue groove and smooth - Revolver, bow-tie
Loose and loamy - Bow-tie, caliber


We've talked a lot about maximizing the forward grip of your car, but what happens when the power plant within your vehicle overcomes the weight-transfer physics of your chassis or the ability of your tires to make grip? Now we have to make changes to harness the extra power to prevent wheel spin and again maximize the available forward grip. This can be done easily through your slipper clutch if your vehicle has one. A slipper clutch is a relatively simple traction control system that allows your transmission to absorb excess power from going to your wheels and creating spin. To set your slipper, place your car on one of the lower traction areas of the racing surface and hammer the throttle. If your tires spin, then loosen your slipper slightly. Keep doing this until you can grab a handful of throttle and launch from your starting position without fishtailing everywhere. This is your perfect starting point; now you can make minor changes to fine-tune your slipper for the rest of the track.


The inserts used within your tires will not affect handling as drastically as tire or tread design, but they still play a role in forward grip. When it comes to off-road racing, a softer insert will give you better side bite, while a firmer insert will increase forward grip. A firmer insert helps to maintain tire shape integrity more closely under heavy acceleration, allowing the tires design to do its job. A softer insert allows more pin flex, which would reduce contact in a straight line and reduce forward-grip slightly. The opposite holds true for on-road inserts. A firmer insert will help prevent your tire from rolling over while side-loaded—increasing side-grip, while a softer insert will increase forward-grip.






Adjusting rear toe angles is one of the quickest, easiest and most reliable forms of increasing rear traction almost everywhere on the racetrack. If you need a bump in forward grip, then try adding 0.5 to 1 degree of toe-in at the rear of your car. You'll be able to accelerate harder out of a turn with the increased rear traction (but keep in mind that increased rear toe-in will reduce your steering through pretty much all phases of a corner).



When it comes to weight transfer and forward traction, two of the most common adjustments affecting front-to-back movement are droop and anti-squat. When dealing with 4WD vehicles, the trick to increasing forward-grip is to try and balance the power amongst all four driven wheels. While under acceleration, your chassis wants to transfer weight to the rear of the car, so adjustments need to be made to help keep weight over the front-driven wheels to fully utilize their traction-providing capabilities (and fully appreciate the advantages of 4WD). When too much weight is transferred to the rear of the car under acceleration, the front-driven tires can unload and spin, reducing their pull in the forward direction. Reducing front droop or increasing rear anti-squat will help to prevent so much weight transfer to the rear of your car maximizing forward-grip.
The opposite holds true for 2WD cars where the front wheels aren't driven. To increase forward traction with this drive setup, you want to transfer chassis weight over the rear tires to reduce wheel spin and maximize forward grip. This is done by increasing the amount of front droop, allowing the front end to rise up further during acceleration and transfer more weight over the rear end. You can also increase forward-grip in a 2WD vehicle by reducing anti-squat allowing the rear suspension to settle more once you tag the throttle.



When it comes to camber and forward grip, it all really comes down to tire patch and surface area against the racing plane. The closer your camber angles are to 0 degrees, the more forward grip your setup will offer. Reducing camber to increase traction in a straight line isn't always the best first move, since you will almost definitely lose grip throughout the turn. Since camber is such a great tool for adjusting for side-grip, there is usually another setup change that can be made to increase forward grip without drastically affecting other aspects of handling.




Scott Hughes needs no introduction, but we'll do it anyway. Pro-Line's front man is also one of nitro off-road's fastest drivers and setup guys. With multiple Worlds finishes and countless National podiums, this guy can win on any given day at the racetrack. After hitting the track with his Mugen MBX-6, here's what he uses to increase his buggy's forward grip.

1st - Tires - The best tire for the track is the most important component for success. Refer to the tire section above for specific tips on tire choice and how they relate to forward grip.

2nd - Rear Toe - Increase rear toe-in for more forward grip, but remember that you'll lose some steering.

3rd - Anti-Squat - Reduce anti-squat to put more weight on rear end under acceleration. (Editor's note: this contradicts some of our story, but with suspension setup issues, nothing is as cut and dry as it seems. Hughes explained that less anti-squat will increase forward grip when off-road tracks are loose or blown out. The opposite is true for high-bite tracks where more anti-squat will increase forward grip. Less anti-squat on high-bite tracks will transfer too much weight to the rear and cause it to wash out or lose traction. This is why 4WD touring cars always increase anti-squat to get more forward grip since all on-road tracks are relatively high-bite compared with off-road racing).

4th - Diff Oils - Lighter diff oil in the rear and thicker oil in the front and center differential will increase forward-grip by helping the front tires to pull the car forward under acceleration.


Martin Crisp is the author of the "XXX Main Racing Touring Chassis Setup Guide" and he is known as a setup god! With multiple A-main finishes at National events as well as Worlds qualifications, Martin knows how to translate his setup ideas into results on the racetrack. Here is the list of changes Martin makes when he wants to increase forward-grip on his Tamiya Touring Car.

1st - Tires - Softer tires offer more forward grip and less side bite. (And softer inserts also offer more forward grip in an on-road car).

2nd - Droop - Reducing front droop will help keep weight over the front-driven tires, increasing forward grip.

3rd - Diff Pulley Height - Raising the rear diff and lowering the front diff will cause more weight to transfer forward under acceleration, causing front tires to offer more grip and thus more forward traction.

4th - Camber - Reducing negative camber to get more contact patch will increase forward grip. You may give up corner speed but you can get that back with other setup changes.


Any form of chassis or tire setup changes can become highly complex regardless of what class you are racing. Remember that one change almost always affects another area of your chassis, so try to match symptoms and find solutions that group issues together. We can theorize all day about what screw to turn or what tires to mount, but the final result should always come from what works best on the race course.