OF-87 Duke Helmet (2024)
The GMAX OF-87 is a premium open face helmet boasting the most desirable features to achieve the epitome of comfort, safety and styling. Dual density SpaSoft and CoolMax interior, optional... Read More
The GMAX OF-87 is a premium open face helmet boasting the most desirable features to achieve the epitome of comfort, safety and styling. Dual density SpaSoft and CoolMax interior, optional LED lighting, well executed ventilation, a quick release buckle, and a drop-down inner sun shield highlight why the OF-87 is the obvious choice for riders who appreciate the inherent value of premium features delivered at affordable prices.
Features
- Lightweight, DOT approved shell
- Anti-fog coated inner drop-down sun shield
- Multi-density SpaSoft, CoolMax comfort liner and cheek pads move the moisture away from your head, and the fabric dries quickly, keeping you dry and comfortable.
- Removable / washable interior and adjustable cheek pads allow for more comfortable sizing.
- GMAX "D.E.V.S." adjustable Dual Exhaust Venting System- top side and rear venting
- Large eye port for improved peripheral range of vision
- Deluxe ear pockets with built-in space for speakers for use of communication systems.
- Soft padded chin strap with quick-release buckle
- Optional new and improved LED light kit (brake light connector sold separately)
- Helmet bag included
How to measure
Measure the circumference of your head one inch above the eyebrows and across the largest portion of the back of the head, then find the matching range. The crown should apply snug, even pressure and cheek pads should be snug (they break in with use). If the helmet moves on your head it is too loose; if it causes pain it is too small. If between sizes, size down.
GMAX size chart
| Size | Head circumference (cm) | Head circumference (inches) |
|---|---|---|
| YL / XS | 53-54 | 20 7/8 - 21 1/4 |
| S | 55-56 | 21 5/8 - 22 |
| M | 57-58 | 22 7/16 - 22 13/16 |
| L | 59-60 | 23 1/4 - 23 5/8 |
| XL | 61-62 | 24 - 24 3/8 |
| 2XL | 63-64 | 24 13/16 - 25 |
| 3XL | 65-66 | 25 5/8 - 26 |
| 4XL | 67-68 | 26 3/8 - 26 3/4 |
Youth sizes
| Size | Head circumference (cm) | Head circumference (inches) |
|---|---|---|
| YS | 49-50 | 19 5/16 - 19 11/16 |
| YM (= XXS) | 51-52 | 20 1/16 - 20 7/16 |
| YL (= XS) | 53-54 | 20 7/8 - 21 1/4 |
One universal GMAX chart covers the whole lineup (street, dual-sport, snow). Youth and adult small sizes share shells and are dual-labeled: a Youth Large is the same fit as an adult XS.
Manufacturer sizing data · verified July 8, 2026