HOW TO MEASURE THE DIAMETER OF YOUR BIKE HANDLE BAR
Handlebars come in all weird styles and sizes, normally it is bended from a tube which have a varying diamater between 22.2mm & 31.8mm; MEASURING BAR DIAMETER The easiest way to measure those handle bars is with a set of digital or vernier scale callipers. If you don’t have callipers then you can use a simple measure tape. Just wrap around the bar at the point you want to attach the locking ring or strap of your gear to get the circumference size and then divide by pi (….mmm) to get your diameter e.g. 99.9mm / = 31.8mm.
If you have no tape, then use a piece of paper (or string). Same as above, just wrap the paper around the bar at the point you want to attach the gear, make a mark with a pen where the paper intersects and then measure against a ruler. This will give you the circumference and to get the diameter just divide by pi. Easy.
Most of the time the area you’ll be attaching the gear to will be either 22.2, 25.4 or 31.8mm and can generally be separated in to the below categories. – Road Bike – Handlebars generally come in two clamp sizes 26mm (older style) and the newer ‘oversized’ 31.8mm. The area where you attach the gear will most likely be either 25.4mm or 31.8mm. – Commuter/Cruiser Bikes – These handlebar sizes do vary due to the wide variety of styles, however most bar sizes would be either 25.4 or 31.8mm – Mountain Bikes – Handlebars generally come in two clamp sizes 25.4mm (older style) and the newer ‘oversized’ 31.8mm. On some bars there will be a bulge in the middle and the bars will thin out towards the brake levers. If you want to attach your gear here, then please make sure you measure as it could mean you move from a large sized tube to a small. For instance the grip area on some of these bars will be 22.2mm, whereas the bulge is 25.4mm. – BMX – Always 22.2mm. Tip : – Normally there will 3 kind for locking rings or washers: 22.2mm, 254.mm, 31.8mm – If your handlebar is any bigger than 22.2mm then you will need to choose the larger washer. – If your handlebar in the middle looks ‘normal sized’, it’s probably 25.4mm. – If your handlebar looks overly big in the middle, it’s probably 31.8mm.