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Simpson Helmet Sizing Chart and Care Instructions


 Inches  Size Size Metric
20   Youth Medium 51
20-1/2 Youth Large 52
20-3/4   Junior 53
21-1/4 54
20-3/8 6-5/8 X-Small 53
21-1/8 6-3/4 54
21-1/4 6-7/8 Small 55
22 7 56
22-1/8 7-1/8 Medium 57
22-3/4 7-1/4 58
22-7/8 7-3/8 Large 59
23-1/2 7-1/2 60
23-5/8 7-5/8 X-Large 61
24-1/4 7-3/4 62
24-3/8 7-7/8 XXLarge 63
25-1/8 8 64

Important Helmet Information

Choosing a helmet is a very personal decision. You must look at many different elements before making your decision based on fit and comfort, safety regulations and product reputation. The buyer must also consider price and style. Simpson offers many different styles to accomodate most types of racing – Auto Racing, Karting, Motorcycle. Our helmets meet the most current safety standards.

Warning – After an Impact

Simpson Performance Products recommends replacement of your helmet after an impact accident or crash. Modern helmets are designed to dissipate energy on impact. After a crash, their effectiveness can be greatly diminished. If you have any doubt about the integrity of your helmet, replace it or at the very least, send it back to Simpson for inspection. Do not take chances with your safety by racing with a compromised helmet.


Q: If all safety aspects of the helmet are the same, why do the prices vary?

A: It is the shape and style of each helmet model that requires extra or difficult steps in production. These extra or difficult steps determine the price.

Q: After an impact, is a helmet OK to use?

A: Modern helmets are designed to disintegrate and dissipate energy on impact. After that, they are finished. If there is any question as to the integrity of the helmet, do not use it. An inspection may be done at the Simpson Factory in New Braunfels, Texas.

Q: My helmet is old but looks new. Is it OK to use?

A: The Snell Memorial Foundation issues increasingly difficult standards approximately every five years. Although a helmet may look new and have received little or no use, it may not meet current Snell standards and should not be used. For additional information about the Snell Memorial Foundation and its test procedures, visit: www.smf.org

Q: What about helmet aerodynamics?

A: Simpson tests its helmets in wind tunnels. To minimize lift and buffeting, “boundary layer separation”or stalled air is created on the helmet surface with the addition of aerodynamically-designed stall strips and a “Gill”vent system. An additional benefit is free cooling.

Q: How do you keep shields from fogging?

A: All Simpson shields are anti-fog coated which reduces the affects of fogging. Also, using any of the Simpson helmets with a fresh air system will aid in removing moisture from the inside if the helmet.

Helmet Fit

1) Measurement

The circumference of the head should be measured approximately one inch above the eyebrows in front and a point in the back that results in the largest measurement. Use the sizing guide to determine size.

2) Try It On

Grasp the helmet by the chin strap with the front of the helmet facing you and the top down. Place thumbs on the inside surface and balance with the index fingers. Slip down over the head. If the helmnet slides down on the head with no resistance, it may be too large. Only if the helmet is impossible to to put on should you move up to the next size. The eyes should be approximately in the center of the eye port, with the top edge of the liner padding just above the eyebrows. If you will be wearing a headsock (recommended), try the helmet on with it.

Check to see if the cheek pads are in contact with the cheeks. Look for gaps between the temples and the forehead pad. Check around the back for a secure fit. Have someone grab the helmet on each side and try to rotate the helmet from side to side. Note any movement of the skin as well as the resistance.

Next check the movement up and down. If in either test there was little or no skin movement and/or the helmet was moved easily, the helmet is too big. A correctly-fitting helmet should feel as if evenly distributed pressure is continuously exerted around the head. Helmets, like shoes, will break in. For this reason the helmet should fit as tight as you can stand to wear it.

4) Retention check

Fasten the chin strap tightly. Have someone reach over the top of the helmet and grab the bottom edge and try to roll the helmet off. If the helmet comes off or moves significantly, the helmet is too big.

5) Now go have fun.



Your helmet should be cleaned and treated with car wax after every use.


Use 320-grit sandpaper to prepare the helmet surface. Sand evenly until all the shine is removed. Paint only with acrylic enamels. Lacquer paints are not compatible and will weaken or destroy the shell. Do not allow any solvent or paint to come in contact with the inner shell.


Shields should be cleaned with window cleaner or 100% pure isopropyl alcohol (do not use rubbing alcohol, must be 100%). Do not use any type of benzene, thinner, gasoline or solvent on the shield.


If the inner liner and/or fit pads are moist due to perspiration or rain, Molecule Refresher will help remove any unwanted odors.


Periodically check helmet straps and hardware for strength and security. Perspiration can compromise their effectiveness.


Motorsports are dangerous. No warranty or representation is made as to product’s ability to protect the user from any injury or death. The user assumes that risk. The preceding was presented with the information available at the time of writing and is the opinion of the writer. It is not meant to be comprehensive nor is it endorsed by SIMPSON. For compete information, contact your sanctioning body.