| Monday | 9.00am - 5.30pm |
| Tuesday | 9.00am - 5.30pm |
| Wednesday | 9.00am - 5.30pm |
| Thursday | 9.00am - 5.30pm |
| Friday | 9.00am - 5.30pm |
| Saturday | 9.00am - 5.30pm |
| Sunday | 10.00am - 4.00pm |
| Bank Holidays | 10.00am - 5.00pm |
2026 GIRO Source Mips Unisex Mountain Bike Helmet in Motion Green
Click & Collect - Always fast, easy & free
Select Click & Collect at checkout and pick up your order at a convenient location
| Monday | 9am - 5.30pm |
| Tuesday | 9am - 5.30pm |
| Wednesday | 9am - 5.30pm |
| Thursday | 9am - 5.30pm |
| Friday | 9am - 5.30pm |
| Saturday | 9am - 5.30pm |
| Sunday | 10am - 4.00pm |
| Bank Holidays | 10am - 4.00pm |
| Monday | 8am - 6.00pm |
| Tuesday | 8am - 6.00pm |
| Wednesday | 8am - 6.00pm |
| Thursday | 8am - 6.00pm |
| Friday | 8am - 6.00pm |
| Saturday | 9am - 5.30pm |
| Sunday | 10am - 4.00pm |
| Bank Holidays | 10am - 5.00pm |
The Source Mips helmet combines advanced performance and protection in a rugged, trail-ready design.
Key Features:
- All Giro helmets are designed to reduce as much energy as possible while meeting and exceeding stringent safety standards. The goal of Giro's Integrated Mips®‐equipped helmets is to reduce rotational forces, while enhancing fit and comfort by combining the Mips slip plane with the helmet's adjustable fit system. Giro believes that helmets equipped with this technology can reduce the amount of rotational force that may be transferred to rider's brain in certain impacts. Learn more about Mips in the video above.
- Giro helmets are developed utilizing our proprietary Wind Tunnel ventilation system. This elaborate design combines active vents in the helmet's shell with exhaust channels inside the helmet that thrust fresh, cool air over and around the rider's head while forcing heat and stale air out. It's the most effective cooling system available, and a difference you can feel every time you ride.
- The industry benchmark in comfort, stability, adjustability and weight savings. In addition to enhancing the comfort and stability of helmets, Roc Loc® 5 allows you to easily custom‐tune the fit tension and fore‐aft tilt of a helmet in seconds, using a single hand. And it's lighter than comparable systems too, making it the ultimate in skull‐hugging luxury.
- Easily adjustable without need for tools or extra fiddling, and offers plenty of vertical adjustment to stage goggles when you're not wearing them.
- The In‐Mold process permanently fuses a light‐yet‐tough polycarbonate shell to the foam liner, eliminating adhesives and excess weight. Our Hardbody design extends that coverage to the inside of the helmet to enhance durability.
- This visor features an adjustment mechanism that lets you move the visor up and down in indexed steps. These steps include three riding positions plus a high position for goggle storage above your brow. The design allows you to easily adjust your visor with one hand while riding.
All UK Mainland Bike Deliveries Over £999 - Free Bike orders are sent via TNT/FedEx with estimated delivery within 1 working day after quoted dispatch time (For Scottish Highlands, Northern Ireland, Isle of Man and the Channel Islands deliveries please allow an additional 1-4 working days).Bike orders under £999 and eBikes will incur a £25 delivery fee.
Free Delivery On Orders Over £199.99 - When you spend more than £199.99 at 99 Bikes deliveries to a UK mainland address will be free (excludes bikes & large items).Certain regions and territories of the UK will incur additional charges, details of which can be found on our delivery page.
Click & Collect Orders -Please be aware Click & Collect orders may take some time to fulfil. We advise not to travel to your chosen store until you have been notified that your order is ready for collection.
At 99 Bikes our priority is to ensure that you are highly satisfied with your purchase. In the unlikely event that you aren't, we offer a 30 day online return policy* in which you can receive a full refund. Any item including bikes (with the exception of food) can be returned to us for any reason provided it is received by us in an unused and resalable condition in or with its original packaging which must be undamaged.
Find Out More About Returns >
| ADULT SUPER FIT SIZE | CIRCUMFERENCE |
| S | 51 - 55 cm |
| M | 55 - 59 cm |
| L | 59 - 63 cm |
| XL | 63 - 65 cm |
| ADULT SUPER FIT FULL FACE | CIRCUMFERENCE |
| S | 51 - 53 cm |
| M | 51 - 55 cm |
| L | 55 - 59 cm |
| XL | 59 - 63 cm |
| ADULT UNIVERSAL | CIRCUMFERENCE |
| Women Adult | 50 - 57 cm |
| Unisex | 54 - 61 cm |
| Extra Large | 58 - 65 cm |
| YOUTH SIZE | CIRCUMFERENCE |
| XS (Scamp Model) | 45 - 49 cm |
| S (Scamp Model) | 49 - 53 cm |
| XS (Dime Model) | 47 - 51 cm |
| S (Dime Model) | 51 - 55 cm |
| Universal Child | 47 - 54 cm |
| Universal Youth (Ages 5+) | 50 - 57 cm |



