Giro Merino Wool Under Helmet Cycling Cap

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Product Description

The Giro Merino Wool under helmet is lightweight, comfortable and stylish on and off the bike. This cycling cap is thin enough to fit under your helmet and is built with sophisticated panelling to prevent any bunching of fabric.

Compared to many cycling caps the Giro Merino Wool under helmet has a shortened brim giving you better upper peripheral vision without compromising on its ability to block the sun and rain.

Key Features

  • Winter weight Australian merino wool blend
  • X-Static liner
  • Reinforced brim
  • Ear flaps fold up or down
  • Size: S-M 51-57cm, L-XL 57-63cm
  • Colour: Black

Occasionally, without notice, manufacturers change product design and/or specifications.

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Giro Size Chart


Use the Giro size chart to find the best fit for you.

Giro Men's Tops Size Chart

Size Chest Sleeve
S (35) 33 - 35" / 83.8 - 88.9cm 34" / 86.4cm
M (38) 36 - 38" / 91.4 - 96.5cm 35" / 88.9cm
L (41) 39 - 41" / 99.1 - 104.1cm 36" / 91.4cm
XL (44) 42 - 44" / 106.7 - 111.8cm 36.5" / 92.7cm
XXL (47) 45 - 47" / 114.3 - 119.38cm 37" / 94cm

Giro Men's Bottoms Size Chart

Size Waist Inseam - Pant Only
28 (XS) 27.5 - 28.5" / 69.85 - 72.39cm 31.5" / 80.01cm
30 (S) 29.5 - 30.5" / 74.93 - 77.47cm 31.5" / 80.01cm
32 (M) 31.5 - 32.5" / 80.01 - 82.55cm 32.5" / 82.55cm
34 (L) 33.5 - 34.5" / 85.09 - 87.63cm 33.5" / 85.09cm
36 (XL) 35.5 - 36.5" / 90.17 - 92.71cm 34.5" / 87.63cm
38 (XXL) 37.5 - 38.5" / 95.25 - 97.79cm 34.5" / 87.63cm

Giro Women's Tops Size Chart

Size Chest Sleeve
XXS (2) 30 - 31" / 76.2 - 78.7cm 30.5" / 77.4cm
XS (4) 32 - 33" / 81.3 - 83.8cm 31" / 78.7cm
S (6) 34 - 35" / 86.4 - 88.9cm 31.5" / 80cm
M (8) 36 - 37" / 91.4 - 94cm 32" / 81.3cm
L (10) 38 - 39" / 96.5 - 99.1cm 32.5" / 82.6cm
XL (12) 40" / 101.6cm 33" / 83.8cm

Giro Women's Bottoms Size Chart

Size Waist Hip Inseam - Pant Only
2 (XXS) 23 - 24" / 58.4 - 60.9cm 33 - 34" / 88.8 - 86.3cm 30.5" / 77.47cm
4 (XS) 25 - 26" / 63.4 - 66cm 35 - 36" / 88.9 - 91.4cm 30.5" / 77.47cm
6 (S) 27 - 28" / 68.6 - 71.1cm 37 - 38" / 94 - 96.5cm 31" / 78.74cm
8 (M) 29 - 30" / 73.7 - 76.2cm 39 - 40" / 99.1 - 101.6cm 31" / 78.74cm
10 (L) 31 - 32" / 78.7 - 81.3cm 41 - 42" / 104.1 - 106.7cm 31.5" / 80.01cm
12 (XL) 33" / 83.8cm 43" / 109.2cm 31.5" / 80.01cm

Giro Men's Gloves Size Chart

Men Palm Width Finger Length
XS 7" or less/ 178mm 6.8" or less/ 174mm or less
S 7-6"/ 178-203mm 6.8-7"/ 175-180mm
M 8-9"/ 203-229mm 7-7.4"/ 181-188mm
L 9-9.75"/ 229-248mm 7.4-7.8"/ 189-199mm
XL 9.75-10.5"/ 248-267mm 7.8-8.3"/ 200-210mm
XXL 10.5" or more/ 267mm or more 8.3" or more/ 211mm or more

Giro Women's Gloves Size Chart

Women Palm Width Finger Length
S 6 - 6.7" / 153 - 169mm 6 - 6.3" / 153 - 160mm
M 6.7 - 7.4" / 170 - 189mm 6.3 - 6.7" / 161 - 169mm
L 7.4 - 8.3" / 190 - 210mm 6.7 - 7" / 170 - 177mm

Read our clothing size guide for more information on sizing.

Please note, all size information is provided as a guide - if you're unsure or need any further assistance you can call us on 01792 799508 ... we're happy to help!

Cycling Headwear Guide


Cycling Headwear Guide

Whether you want to stay warm on cold rides or keep the sun out of your eyes on clear days, cycling specific headwear will help to make your ride more comfortable.


Cycling headbands are designed to cover your forehead and ears while wearing a helmet. Depending on the type they can be used for warmth and wind protection in the winter or sweat management in the summer

Windproof headbands offer useful cold weather protection while still allowing your head to breath, so you don’t overheat. The windproof properties of a headband are a great way to prevent ear discomfort when riding in cold weather.

cyclist wearing glasses and a headband

Thermal headbands combine windproof properties with a thermal layer for extra warmth. These protect your ears from wind bite as well as helping you stay warm.

Mesh headbands are made from lightweight breathable material. Ideal for summer cycling they soak up your sweat and allow it to evaporate rather than run down your face.

Endura cycling headband

Skullcaps & Beanies

Skullcaps are designed fit under your helmet coving your head and ears. They usually combine windproof and thermal properties to keep the wind off your ears and help you stay warm on cold rides. Skullcaps are made from four-way stretch materials with pre-shaped panels for a comfortable cycling fit.

Beanies aren’t designed to fit under a helmet, so they’re best for pre or post ride wear. A great way to keep warm while you’re waiting for your mates to get ready to ride.

Castelli cycling Skullcap

Caps & Hats

Cycling caps are the traditional headwear for road cyclists. Lightweight and close fitting with a small ‘upturnable’ peak they are good for wearing under your helmet. Lightweight caps are a good way to keep the sun off your head and out of your eyes when road cycling.

Cyclist wearing endura winter cycling cap under helmet

Thermal or winter cycling caps are cycling the same as skullcaps but with a peak. Made from thermal and/or windproof fabrics they help to keep you warm and stop the wind from biting your ears. The peak will help to keep the sun out of your eyes on those bright but cold winter rides.

Casual caps, snapbacks ad wide brim hats are great for chilling out post ride, but don’t fit comfortably under a helmet.

Endura winter cycling cap


Underhelmet headwear offers more head and neck coverage than a skullcap. As the name suggests they are designed to be worn under your helmet and are made from thermal and/or windproof fabrics to help you stay warm in the coldest of conditions. Balaclavas are the ultimate in cold weather cycling headwear.

Cycling balaclava

Neck Warmers

Multitube, snood, buff, head thingy? Neck warmers have many names, but the principle is the same. These lightweight stretchy tubes are perfect for wearing around your neck for a little extra warmth. You can easily pull them up over your face against the wind on really cold rides. Neck warmers can also be worn on your head like hat or headband.

cycling neckwarmer

Delivery & Guarantee

UK Delivery Information

International Deliveries – Temporarily Suspended 11/11/20

Note: We are still offering deliveries to the Isle of Man, Scottish Highlands, Scottish Islands, Channel Islands, Isle of Wight, Jersey and Guernsey. 

Courier Delivery update: Due to the COVID19 situation, we are currently experiencing some delays with deliveries. Our couriers are working around the clock to get your order to you as soon as possible but there is a potential delay of up to 48 hours . Please check your tracking on track your order here.

Please download the TNT Track and Trace App for iOS here and Android here so you can keep an eye on your delivery and any further updates.

Please note on the TNT tracking app it may show your delivery status as ‘Collecting’ (as per image below). This means your delivery has left our warehouse and is currently held at TNT main depot and there could be up to a 48 hour delay.

tnt delivery

Please keep checking the TNT tracking for further updates. On behalf of TNT we apologise for any delay and inconvenience this may cause. 

We are committed to offering fast and free delivery, whether you're ordering bikes, accessories or clothing. Our standard delivery service is FREE in the UK, regardless of the size and on all orders over £20.

Please note that bulky products and bikes shipped to outlying UK regions are excluded from free shipping.

Please note that Pre-Order dates can sometimes change due to updated stock information.

Click here for more UK and international delivery information.

Returns & Warranty

It's easy to return a product with our 365 day, hassle free returns. 

We will give you a full refund on any item that is returned to us unused/unfitted, in a resaleable condition and in its original packaging (where possible).

Please note: For hygiene reasons, we cannot accept returns of facemasks, undershorts or underwear if the item has been removed/unsealed from its original packaging.

If your item develops a fault or arrives damaged, please contact us first so we can resolve the issue for you as quickly as possible.

For more information please visit our Returns & Warranty page.