• I. Determine the Size Needed.

    Measure the head using a cloth measuring tape, or a piece of stringyou can measure with a ruler afterward, approximately one inch above the eyebrows around the full circumference of the head.

    Once measured, you should have a measurement in either inches or centimeters.

    Use this measurement, along with the Troxel Sizing Chart, to identify the appropriate size as Small, Medium, or Large.

  • II. Prepare the Helmet for Fitting.

    Make sure all the Flip-Fold pads are flat and not flipped under. Most Troxel helmets incorporate a stabilization system, a GPS (Gripper Positioning System). Identify which GPS system the helmet has:

    • GPS I - This system uses a 'Y' shaped piece of equipment in the back of the helmet to reduce bobbing of the helmet.
    • GPS II - This system uses a soft-touch dial to customize the fit. (Figure A))
    • GPS III - This system uses a mechanism the rider 'pinches' together to adjust the fit. (Figure B)
    • Verify one of the following:

      • The GPS I is pulled all the way down and back; or
      • The GPS II dial is let out all of the way; or
      • The GPS III is completely opened to the widest point.
    A
    B
  • III. Prepare the Headliner for Fitting.

    1. Try the helmet on to ensure it fits the head comfortably without causing any pressure points, such as squeezing the sides of the head or pressing on the forehead.
    2. If the helmet feels too tight, move up to the next size.
    3. If the helmet is loose, engage the Flip-Fold pads by folding them under to create a snugger fit. If the helmet still feels too loose once all the Flip-Fold pads are folded under, remove the existing THIN Flip-Fold liner, and replace with the THICK Flip-Fold liner provided in the box, and adjust accordingly. (Figure C)
    4. If the helmet is still too loose with the THICK Flip-Fold pad folded under to the thickest adjustment, then go down a size and begin the fit process from Step 2.
    C
  • IV. Customize the Fit Using the GPS.

    After the headliner is adjusted, further fit the helmet by adjusting the GPS stabilization system in the following ways:

    Adjust the GPS I by sliding the GPS snuggly to cup the back of the head.

    Adjust the GPS II by turning the dial to tighten the GPS. (Figure A)

    Adjust the GPS III by pinching together the micro adjustable slides to snug the GPS system to the head. (Figure B)

    Keep in mind, when adjusting the GPS there may be increased pressure on the forehead. If this occurs, simply let out the GPS a little or readjust the Flip-Fold pads.

  • V. Evaluating Helmet Fit

    • Fit - The helmet should feel snug around the entire head without pressure points.
    • Position - The helmet should sit level on the head and the forehead is covered within two fingers width of the eyebrows. (Figure D)
    D
  • VI. Positioning Straps and Buckles.

    • Side Straps - Adjust the triangle shaped slider on both sides of the helmet to form a 'V' shape under and slightly in front of the ears. (Figure E)
    • Chin Strap - Roll the rubber band keeper towards the triangle shaped slider on the side strap. Put the helmet on and buckle the chin strap. Starting with the straps loose, hold onto the buckle with one hand and tighten the straps by pulling the ends straight out with the other hand. No more than one or two fingers should fit under the tightened chin strap. Roll the rubber band down towards the buckle while folding the straps under the rubber band to secure them. (Figure F)
    E
    F

Helmet Fit Tests

  • Open your mouth in a big yawn. The helmet should pull down on the head. If not, tighten the chin strap.
  • Does your helmet rock back more then two fingers above the eyebrows? If so, unbuckle and shorten the front strap and then retighten the chin strap and test again.
  • Does your helmet rock forward into your eyes? Is so, unbuckle and tighten the back strap and then retighten the chin strap and test again.
Head Size Inches Head Size CM Hat Size
20 38 52 6 12
20 78 53 6 58
21 18 54 6 34
21 12 55 6 78
21 78 56 7
22 14 57 7 18
22 58 58 7 14
23 59 7 12
23 12 60 7 12
23 78 61 7 58
24 14 62 7 34
24 58 63 7 78
25 64 8
25 12 65 8 18
Disclaimer: This conversion chart is a guide only and does not constitute a guarantee as to the fit of the helmet. Some people may have a unique head shape changing what size they need. Some helmets fit different shaped heads better than others.
  • Published:
  • Updated: 9/22/2022: 4:19:45 PM ET
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