Sorry, this product is no longer available!
Giro Trinity Road Cycling Helmet is no longer available at Merlin Cycles. However you may find an alternative or updated product below.
Giro Trinity Road Bike Helmet
Giro Trinity Road Bike Helmet

This item was discontinued 4th November 2016.

If you require help finding an alternative to this product please contact customer services.

The Trinity helmet from Giro is simplistic in its design yet includes top-level features such as In-Mold construction & their Acu-Dial system. Geared for recreational cycling, it still delivers an easy fit & does not compromise on comfort or performance.
Features of the Giro Trinity Road Cycling Helmet
  • A quick fit with style for any ride
  • In-Mold polycarbonate shell with EPS liner
  • Acu-Dial fit system
  • 22 vents for good ventilation
  • Available in four colours
  • Sizing (Universal)
  • One Size 54-61cm
  • Suitable for Road and MTB

The on-the-fly Acu-Dial system allows you to make adjustments for maximum comfort and stability with the In-Mold construction making it light without compromising durability.

The Acu Dial system combines single-handed adjustment with a full fit band that brings a quick, sure ponytail-compatible fit in their line of Universal Fit helmets.
In-Mold Construction
In-mold construction fuses a tough polycarbonate outer shell with the helmet’s impact absorbing foam liner. The fusion process allows Giro to sculpt better ventilation systems, so In-mold helmets can be lighter and cooler than traditional helmets.
To determine the correct helmet size wrap a tape measure around your head keeping the tape just above the ears and level front to back.


These Helmets are certified with a European CE EN1078 standard. This is a European standard and although the helmet is perfectly safe to use, specific countries may have their own certification which is legally required if you intend to wear the helmet recreationally or in a competitive racing environment. If you are unsure, please check your specific country requirements and check with the manufacturer to see if the helmet has received any additional certification.

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Shipping charges for this item to United States: $6.43

Spend $64.25 or over and get free shipping
$ 6.43
General information about our shipping

Sizing Information for Giro Helmets:

Giro Helmet Sizing Chart

Great fit for me. It has a very nice design and it feels light. Great for the price.
Good quality product, fits all sizes and looks good. Fantastic bargain.
I bought this for use over the winter instead of my lighter more expensive helmet. It's great, the adjustability is as good as any other I have tried particularly on the side straps which many helmets now seem to have fix the Y position. Very pleased with the helmet especially at this price.
I love the fit of this helmet. It's nice and fitted, doesn't move unnecessarily.
Helmet fits well and is comfortable to wear. Good quality product.
Excellent cost benefit, fast delivery until the arrival in Brazil. Helmet very light and comfortable for its price range. I recommend buying!
Got this as a gift and the receiver loves it. Fits well and seems sturdy.
Very comfortable helmet
Nice helmet, fits well, looks well made too, just the job.
Fast shipping. Helmet suitable for everyday use. Very light and the price is cheap. Good design, nice color.
Clean lines, comfortable, user-friendly and at a competitive price
Great helmet at a fantastic price. Would recommend to anyone looking for a comfortable functional cycling helmet
Comfortable and lightweight. I cycle to work and this is a good helmet for my purposes
Needed a new helmet to go with my new bike so when this was advertised by Merlin, I bought one immediately, its comfortable and does exactly as described once again would definitely recommend this item for all riders.
1st Class service and product from Merlin, ordered on the Wednesday afternoon and dispatched the following day with free postage, it doesn't get better than that! Great starter road bike helmet, nice style and choice of colours. Very comfortable - quite honestly I forget I'm wearing most of the time. Yes, there will be better helmets out there but for the price and service offered you won't go wrong!