Select: Handlebars Grips
Natural angle: Close your eyes, clench your hands in a fist, relax, and put both arms forward and down a little. That is the natural position of your hands. They form an angle, called θf, viewed from the front, and another angle, called θt, viewed from the top. Handlebars are all close to the average natural position of human hands.
Positioning: Clamp-on handlebars can rotate in the clamps. During installation the rider chooses the best clamping position, for comfort and control. Most handlebars (except Clubman) are positioned with the rising part going straight up when viewed from the side. A rider with short arms might prefer a more rearward position, while a rider with long arms might want a more forward position.
Flipping (inverting): Any clamp-on handlebar can be flipped over (inverted). But most will feel wrong and strain the wrists. Of the handlebars shown below, only the Clubman and Drag bars can be flipped over, and still feel right.
Dimensions: Six lengths can completely describe a handlebar, without the need for angles. Here the side-view angle θs, and the top-view angle θt, are calculated from the lengths R, H, P, L, W, and C.
tan(θt) = 2*P / (W-C)
sin(θf) = (R-H) / L
Measuring: When measuring the dimensions, the end points are at the centers of the tubes, not the edges. The handlebar is placed on a flat table. With the rises vertical, the rise and height are measured from the center of the bar, straight down to the table, with 1/2 of the bar width subtracted (-0.4 inch). With the rises horizontal, the pullback is measured similarly.
Height: Looking from the front, most handlebars, especially low ones, slant down slightly going outward, at an angle θf, because the height is less than the rise. On some handlebars, the height is greater than the rise, and θf is negative.
Pullback: Looking at most motorcycle bars from the top, the bars slant rearward, at an angle θt, because the pullback is greater than zero. When the pullback is zero, θt becomes zero. Cruiser bars are for comfort and have a large pullback, where the bar ends point more towards the back of the bike. Drag bars are for high powered acceleration, and have a small pullback for control and grip.
2D or 3D: When the pullback is zero, the handlebar is 2-dimensional and will lay completely flat. Otherwise, most 4-bend (non-Drag) bars are 3D and do not lay flat on a table. 2D handlebars are simpler to make, but don’t feel “right”, except maybe at one particular position. 3D handlebars are more complicated to make, but will feel “right” in a range of positions.
Width: Wider handlebars allow better control. Off road bikes have wider bars. Narrow bars have less control, but are more aerodynamic for better fuel economy or higher top speed, and can squeeze through smaller spaces, like in between stopped cars.
Rise: High rise handlebars are taller, and put the hands higher. This can position the rider’s torso in a more upright position, for helping with back pain. Higher bars allow better control when standing up, like when jumping or hitting pot holes. Low rise handlebars put the rider leaning more forward. That reduces wind drag for higher top speed or better fuel efficiency.
Control length: Motorcycle handlebars need about 3 inches more control length than bicycle handlebars. They have thumb-operated levers or buttons, in addition to the finger-operated hand levers. Motorcycles have a twist throttle and a hydraulic brake on the right that takes up space. For motorcycles the minimum control length is roughly 8 inches. For mopeds it is about 6 inches. For bicycles it is about 5 inches. Any handlebar that has extra control length, can be cut shorter, up to the minimum control length, to reduce it’s width.
Clamp length: The center straight area needs to be at least as long as the clamps. Motorcycles have wider handlebar clamps than mopeds. Here is a table of moped handlebar clamp spacings:
xxxxxxxxx xx inner outer
Tomos A55 xx 1.7″ xx 3.1″ only this fork has enough inner space for bicycle bars with a 1″ x 1.7″ center bulge
Puch Maxi xx 1.55 xx 3.2
Hercules xxxx 1.2 xxx 2.4
Peugeot 103 x 1.2 xxx 2.3
Cimatti xxxx none xxx 2.4
Motobecane x 1.5 xxx 2.7
Applications: Not all mopeds can accept clamp-on “universal” handlebars. Some mopeds have bolt-on handlebars, where there are plates welded to the bar that bolt to the fork. Some mopeds have stem-mounted handlebars, where there is a long neck that goes inside the fork, held by a wedge bolt.
Thickness: Most modern 7/8 handlebars are 0.875 inch = 22.2 mm.
Vintage metric handlebars, are 0.863 to 0.866 inch = 21.9 to 22.0 mm.
The dual standard can sometimes cause problems.
22.0 controls on 22.2 bars: Wedge type controls, such as Domino, for 22.0 bars cannot fit on 22.2 bars. Wedge type controls do not clamp, but instead press a cone into the bottom of the handlebar. 1960’s, 70’s and 80’s “vintage” Domino controls have a fixed size hole, 22.0 mm, for 21.9 bars.
22.2 controls on 22.0 bars: Original vintage handlebars 22.0, with 1970’s Magura clamp type controls, require a strip of aluminum can under the clamp, to hold solid onto the handlebar. Otherwise the throttle slips around the bar. 1990’s and 2000’s “modern” Domino wedge type controls have a 22.3 mm hole, that works fine on either modern 22.2 or vintage 22.0 bars.