Merino wool is to Icebreaker, as what olive oil is to the Greeks. They make absolutely everything out of it and they’re not afraid to tell you it’s the best. The Kiwi’s are well deserving in their reputation though and these days they’re getting quite proficient at working with the fine-grade sheep’s wool on all sorts of different garments. For this Winter, their Quantum arm warmers see further refinement in both fit and construction that is echoed across their wider cycling range. We take a look at the furry warmers to see how they stack up against the synthetic competition.


Icebreaker Quantum Arm Warmers

  • GT260 Fabric
  • Terry-style internal layer
  • 98% Merino Wool, 2% Elastane
  • Elastic upper bicep gripper
  • Elastic cuffs
  • Reflective logo detail
  • Sizes: XS, S, M, L, XL
  • RRP: $49.95


“The Quantum Arm Warmers from our Icebreaker GT technical sports range are made from cosy GT260 terry fabric that stretches as you move. They’re ideal for when you need extra warmth but don’t want another layer – when you’re cycle training early in the morning, simply peel them off when the day heats up. Griper elastic at the bicep holds the Arm Warmer in place under a short sleeve top.” – Icebreaker


Initial Impressions
The Quantum arm warmers are built from a mid-weight 260 Merino wool. Icebreaker use the numbering system to denote how many grams of wool there are per square meter – the more grams, the thicker the wool. Generally you’ll find lightweight garments suited to warm conditions will come in around the 120-150gm/m2 mark, whilst base layers sit around the 180-250gm/m2 weight.


The fabric features a fleece-like finish on the inside that Icebreaker refer to as a ‘Terry’ pattern, though this finish is more widely known in the cycling world as a ‘Roubaix’ style. This internal layer helps to trap more air pockets in the garment for better insulation than a garment without. The official fabric name is ‘GT260’, with the GT part of the name referring to the 2% Lycra mix through the Merino to help provide stretch. The Lycra weave also helps boost the strength of the fabric – a common complaint with Merino wool for hard-hitting riders. Icebreaker make a range of products with the GT blend, including leggings, snug-fitting undershirts, cycling shorts and jerseys.


The Quantum’s use a basic tube cut without any panels like a lot of other arm warmers we’ve used, but because of the waffle pattern in the thread and the gentle stretch in the elastine they fit beautifully snug. With the basic shape and the lack of panelling, there’s only one seam down the length of the arm warmer and it uses a flat lock stitch that’s largely unnoticeable on your skin. The Quantum Arm Warmers utilise an elastic gripper around the bicep along with an elastic cuff to keep them in place, and you can get them in XS through to XL sizes.


Our Take
Like other Merino wool garments, we found the Quantum arm warmers to regulate temperature very effectively. They have good warmth at the start of the ride and great breathability as you heat up, allowing you to ride longer before having to remove them. Concerns about the lack of ‘articulated panelling’ were quickly put to bed, as the snug fit didn’t exhibit any bunching up. In fact, it was the lack of stitching and seams that we noticed (or rather didn’t notice) the most, which made them so comfortable.


Our only complaint with fit was that the upper elastic bicep gripper could have been a touch tighter, while the wrist cuff could have been a touch looser, though fit will obviously vary from rider to rider. Sizing seems to follow jersey size well, so if you’re a Large jersey, a Large size in the Quantums is a good start, unless you have bigger/smaller arms than average.

For mountain biking, the Quantum Arm Warmers are supremely versatile, and along with your jersey and a base layer (such as the Icebreaker Oasis Short Sleeve) you have a lot of flexibility for mixed conditions versus a one-piece garment. We didn’t experience any durability issues, though while the GT fabric is a little tougher than regular Merino, there will still be some sacrifice in abrasion resistance compared to a synthetic fiber. However, after having embraced the breathability, soft comfort, and anti-stink properties of the natural fiber, it would be hard for us to go back to anything made from plastic again.

The Quantum’s come thoroughly recommended: for premium arm warmers that are comfortable and beautifully soft to the touch, they’re also great value too.

To checkout the full Icebreaker range and for more info on the Quantum Arm Warmers, head to: