An all year round wonder accessory, arm warmers and arm protectors are a great addition to your cycling wardrobe. They can be the defining item of clothing for your ride enabling you to take a lighter jacket or none at all; ensuring you're protected against wind and cold during winter or UV rays and sunburn during summer. They can be easily removed and shoved into a pocket if not needed and small enough to keep stored for use when there is a sudden change in temperature.
When purchasing are warmers considerr what you will wear over the top. If you plan to wear a tight sleeved jacket be sure to think about how tight they are around the elbow when you are in the riding position as you don't want to restrict circulation in your arms or hands. Summer and winter arm protectors/warmers may differ in size due to thicker fabric or fleece lining, so be sure to double check your sizing.
Once you know how your body temperature reacts during your rides in different clothing you will be able to distinguish what kind of arm warmers are best. Whether you prefer to go heavier or lighter on the material when paired with other items such as thermal jerseys or jackets. Each brand of arm warmer will vary in measurements, the kind of grips used to keep them up, the product design and any technologies used such as waterproofing layers including Gortex. All these details change how they feel in action and the product flexibility, so when possible it is advisable to try a few different brands and styles to find what suits you and works best for your ride.
They shouldn't cut your arm in two at the top nor should they flap around your wrists.