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Comfort and style for the trail
Get ready to rip with this top-of-the-line half shell trail helmet with deeper coverage, a three-position visor, Blendr mounts, integrated sunglass storage, and more. Trek Rally WaveCel also features updated WaveCel helmet technology with 10% larger cells for more airflow and 15g of weight savings.
"Would I recommend the Rally to a friend? It’s an easy yes."
"...a comfortable, feature-packed trail lid with exceptional safety ratings."
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"WaveCel outperforms traditional foam cycling helmets."
"...the new Rally and Quantum helmets includes deeper rear coverage, protecting the back of the head. Plus, Trek’s Crash Replacement Guarantee provides a free replacement within the first year of ownership if you’re involved in a crash."
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All your favorites, all in one place
Get all your favorite apparel from over 80 of the world's best cycling brands delivered right to your doorstep or local Trek retailer when you shop our curated online collection. If you're not 100% satisfied, you can return your purchase within 30 days for a full refund.
Shop all gearGo By Bike
Planet Earth is our home and our responsibility —we must do our part to preserve it. Learn how you can join the #GoByBike movement and help make a difference in the future of our planet and all who call it home.
Read moreHow to ride safer
Want to do more than wear a helmet? Check out this guide to riding safer.
Learn moreHow to clean your bike helmet
To ensure your bike helmet looks and performs its best, it's important to properly clean and care for it. Check out our simple guide to learn how to maintain your bike helmet. It's easy to do and takes little time!
Read moreProduct features
WaveCel helmet safety technology
WaveCel is a revolutionary helmet technology designed to be more effective than traditional foam helmets in protecting against certain cycling-related accidents. Its collapsible cellular structure lines the inside of your helmet and is designed to work like a crumple zone to absorb the force of an impact before it reaches your head.
Crash Replacement Guarantee
We'll provide you with a free replacement helmet if it's involved in a crash within the first year of ownership. Just contact us or your local retailer with the crashed helmet, original sales receipt, details of the incident, and a return address for your replacement.
5-star Virginia Tech rating
All WaveCel helmets received the highest rating from Virginia Tech's third-party testing facility. This unbiased assessment proved Trek's WaveCel helmets to be among the highest level of protection available to cyclists with a 5-STAR rating.
Lighter and cooler
New-and-improved WaveCel technology features 10% larger cells that allow for more airflow while saving weight.
Deeper coverage
An extended back-of-helmet shell offers additional protection around the rear of the head.
Sunglasses storage
Grippy sunglass storage channels make it easy to secure your sunnies mid-ride.
Three-position visor
Get the look and sun protection you want with an adjustable visor that easily sets into three positions.
Removable Blendr mount
A removable Blendr mount makes it easy to mount a light or camera when you want it, or opt for a cleaner look when you don't.
Micro-adjustable BOA® fit system
Easily secure and adjust the helmet fit with just one hand.
Secure magnetic buckle
A Fidlock magnetic buckle fastens effortlessly for a quick, secure fit that can easily be fastened or unhooked with a single hand.
Helmet buyers guide
Not sure which helmet is right for you? Check out our helmet buyer's guide to learn everything you need to know about bike helmets.
See the guideCrash Replacement Guarantee
With our Crash Replacement Guarantee, we will provide you with a free replacement helmet if it is involved in a crash within the first year of ownership. Simply contact us or your local retailer with the crashed helmet, original sales receipt, details of the incident, and a return address for your replacement.
Learn more30-Day Unconditional Guarantee
If for any reason you're not satisfied with a Bontrager or Trek aftermarket purchase, return the item, along with the original sales receipt to the original place of purchase within 30 days for an exchange or refund. Think of it as a 30-day test ride.
Learn moreOur helmets build the future
$1 from the sale of every Bontrager helmet in North America supports PeopleForBikes, which provides guidance, a rating system, a leadership conference, and professional support for transforming cities throughout the United States in the ongoing effort of becoming a bicycle friendly nation.
Learn moreHelmet Fit and Sizing
For your helmet to do its job, it's important that it's sized properly and fits well. Reference our sizing guide at the link below to find your ideal size and see how Bontrager helmets are intended to fit.
Learn more| Size | S | M | L | XL |
|---|---|---|---|---|
| Circumference | 52-56cm | 55-59cm | 58-62cm | 61-64cm |
| Fit system | BOA® | BOA® | BOA® | BOA® |
| Pad material | Moisture wicking pads | Moisture wicking pads | Moisture wicking pads | Moisture wicking pads |
| Buckle type | Fidlock buckle | Fidlock buckle | Fidlock buckle | Fidlock buckle |
| Includes | Crash Replacement Guarantee | Crash Replacement Guarantee | Crash Replacement Guarantee | Crash Replacement Guarantee |
| Weight | 365g | 380g | 410g | 425g |