After spilling coffee all over my backpack during my commute, or all over my hands while precariously holding my mug while biking, I finally invested in a bike coffee cup holder. Some might say that I could just use a seal-proof thermos and put it in my bag, and I do that also, but in addition, I have my not seal-proof mug for instant coffee drinking.
This product is handy because it attaches to you handlebars, so you can also take sips of coffee while en route and waiting for a streetlight to change. The design is sleek and fits most handlebars with its adjustable attachment. The ring is reduced/ chambered to allow for a variety of different diameters of mugs to fit, and uses the weight of the mug and the grippy inner surface to make a snug, not shaky fit. The only potential issue is that if the diameter of the mug is smaller than that of the smaller diameter of the holder, it will just fall through. Similarly, if the mug has a handle that is not positioned high enough with relation to the mug’s center of gravity, there is a chance it could tip over. I tested my different mugs before committing, and several of mine work. I’m pretty happy with this product, and it is a lifesaver on Cambridge’s pot-holey roads.