Smith Mainline Helmet - Thunder Mountain Bikes
Smith Mainline Helmet - Thunder Mountain Bikes
Smith Mainline Helmet - Thunder Mountain Bikes
Smith Mainline Helmet - Thunder Mountain Bikes
Smith Mainline Helmet - Thunder Mountain Bikes
Smith Mainline Helmet - Thunder Mountain Bikes
Smith Mainline Helmet - Thunder Mountain Bikes

Mainline Helmet

SKU: E007421O65962

Regular price$310.00
Shipping calculated at checkout.
  • Low stock - 2 items left
  • Backordered, shipping soon
  • Free shipping on all orders $59+

From your trusted gear to the legs powering you through, every element plays a crucial role. Crafted for those who thrive on speed and adrenaline, the Smith Mainline stands as the pinnacle of downhill-certified enduro bike helmets.

Featuring cutting-edge safety technologies such as KOROYD™ and Mips®, this helmet ensures unparalleled impact protection, granting you the confidence to push your limits on any terrain. Whether conquering the challenging trails of the EWS in Whistler or tackling the final stage of a local enduro race, you deserve a helmet that breathes with you, feels feather-light, and gives you the confidence to go big.

The Mainline's design facilitates efficient venting and prevents lens fogging, ensuring clear vision throughout your ride. With multiple pad sets offering customizable fit options, achieving a perfect fit is effortless.

Smith Mainline Features:


  • Complete KOROYD® coverage for lightweight, ventilated, and energy-absorbing impact protection
  • Mips® Brain Protection System mitigates rotational forces from angled impacts
  • CPSC CE EN 1078, ASTM F1952 downhill, and NTA-8776 E-Bike certified

Fit & Integration

  • Seamlessly integrates with Smith performance goggles for optimal comfort, venting, and storage convenience
  • AirEvac ventilation system prevents fogging, ensuring clear vision
  • Customize fit with three washable cheek pad kits, two crown liners, and two neck rolls
  • D-ring chin strap fastener ensures a secure fit

Feel & Function

  • 21 fixed vents ensure consistent airflow
  • Adjustable visor for personalized preferences
  • Hybrid X-STATIC® / Ionic+® anti-bacterial performance lining prevents odor buildup
  • Weight (Size M, Mips®): 27 oz / 770 g

Please reach out to us with any questions you may have on anything we sell. We want to make sure you get the right items the first time. Our lifelong riders at Thunder Mountain Bikes are knowledgeable and would love to talk to you!


We currently offer both economy and expedited shipping options though FedEX and USPS.

Orders totaling over $59 are eligible to ship for free via an economy ground option of our choice.

Most bikes ship free within the continental US. Bike shipping to AK, HI, or PR is $250.

If you're in need of something super-quick, please contact us directly. We may be able to overnight your order with an additional fee and depending on your location.


Should there be an issue with the item you bought, or you no longer need your purchase, we will be happy to set up a return.

Component & Gear Returns

Returns may be requested within sixty (60) days of the delivery date. All returned items must be received in new, unused, and uninstalled condition, with the original tags and labels attached and in the original packaging. We cannot accept returns on any items installed or show wear of any kind.

Bike Returns

Returns or exchange requests for bikes must be requested by emailing us at within fifteen (15) days from the date of delivery. Bikes must be in un-ridden condition. Custom-built bikes may not be returned. Returned bikes have a $200 restocking fee and the customer pays for return shipping.

Return Shipping

Customers may choose to use our provided flat-rate return shipping label at $9, or choose a carrier of their choice to handle their product return.

The $9 flat rate label will be deducted from the refund issued for the return. You can either print this label after requesting a return from the Order History in your Account profile, or you can request that we email you the label.

For all other return shipping methods, please email us at after submitting your return request so that we can confirm the shipping information you should use to return your item(s).


We will process your return after we receive your returned item(s) and inspect the condition. Please allow at least seven (7) days from the receipt of your item to process your refund. We will notify you by email when your return has been processed.


If you receive defective or damaged products or if we sent you the wrong products, please contact us using the phone number or email below.


To request a return, please log in to your customer account by clicking the customer account icon Profile icon in the top right of any page or visit

1. In the Email field, enter your email address and click Continue.

2. In your email account, open the email sent from our store and copy the six-digit verification code included in the email.

3. Go back to the online store and enter a six-digit verification code to log in.

4. Find and click on the order that you want to submit a return for.

5. If your order has more than one item, select only the items you want to return.

6. Select a return reason and add a note for the store if needed.

7. Click Request Return.

Once your return request is approved, you will receive an email with shipping instructions and a return shipping label.


If you have any questions concerning our return policy, please contact us at:

(928) 282-1106   |

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Customer Reviews

Be the first to write a review

You may also like