Handlebar diameter. It’s something you’ve maybe never thought about before, but suddenly, you’ve come across the Route Werks Handlebar Bag and need to know…will a 31.8mm Bike Mount fit my bike?? Luckily, it’s pretty easy to figure out the diameter of your bars using a few simple tools you probably already have at home. 

Method 1: Calipers

If you have a set of digital or vernier calipers, this is the easiest way to find the diameter. Simply put the calipers on your handlebar on either side of your stem (where you would attach the Route Werks Bike Mount). Voila, the calipers should now show your handlebar diameter. 

Method 2: Flexible Tape Measure

Grab a flexible measuring tape (metric preferred) and wrap it around your handlebars on either side of your stem. This measurement is the circumference – you will now need to take that number and divide it by 3.14159 to get your diameter.

If you only have an imperial measuring tape, totally fine. Just take your circumference in inches and multiply it by 25.4 (or run it through an online conversion calculator), then divide that number by 3.14159.

Method 3: Standard Ruler + Paper (& pen)

Even if you don’t have calipers or a flexible measuring tape, you probably have a ruler and some paper at home. Cut a thin strip of paper and wrap that around your handlebars as you would in Method 2, above. Mark the measurement on the paper with a pen or pencil, then lay that piece of paper next to your ruler. Continue on with the instructions above for calculating diameter from circumference, or converting imperial to metric and then calculating circumference. 

Need a quick visual? Watch this video to see the above tips in action. If you do happen to find out that our standard 31.8mm Bike Mount won't quite work, no sweat, we have 26.0mm and 25.4mm Bike Mount Adapters that'll do the trick. Happy riding!