What different kinds of bike handle bars are there? All kinds welcome, the common and the nameless.
If possible include the pros and cons of the bar
One bar per post
The simplest kind of handlebar, these are a straight bar with grips on the end. Flat bars were traditionally only used by cross-country riders but now you see them in more general application.
Flat bars (image credit)
Flat bars offer more space to mount lights and computers than drop bars. These bars have bar ends attached for additional hand positions. (image credit)
Typically seen on road, track (sprint), and gravel bikes. Designed to give the rider multiple hand positions, as well as the ability to "tuck in," decreasing wind drag. These can be fitted with aerobars for additional aerodynamic advantage.
Drop bars offer these hand positions.
Not pictured is the "hoods," which are part of the brake levers. These positions will be referenced below.
Drop bars have a number of critical dimensions.
The most important is width, which typically ranges from 38–44 cm for road bars, wider for gravel bars. This is usually sized approximately to the rider's shoulder width.
The next major dimension on drop bars is the drop: the distance between the tops and the drops.
The third major dimension is the reach: the forward extent of the bars.
Another dimension that is not related to rider fit is the center ferrule diameter: this is the interface between the handlebar and stem, and the two need to fit. With quill stems, this is typically 26.0 mm (except for Cinelli bars, which were very popular, and used 26.4 mm). With clamp-on stems, most bars use a 31.8-mm ferrule, although 26.0 mm and other sizes are still seen.
Although they look similar, there are a number of styles of drop bars for different styles of riding. Drop bars have also evolved with other changes in bike technology. These styles are mostly referred to as "bends." There are variations (or variations on variations) not listed here.
The classic drop bar, this uses bends that are arcs of circles. These came into widespread use around 1960, and remain fairly popular.
The ergonomic or anatomic bend appeared around the year 2000, and is characterized by fairly sharp bends between positions, and straight runs of tubes (or even reverse bends) along the hand positions. These can still be found, but have largely fallen out of fashion.
Modern ergonomic bars typically use continuously curved sections, but with more complex curves that are not arcs of circles. They may have other more complex shaping features as well.
Both old- and new-style ergonomic bars typically have much shallower drops than Maes-bend bars. This is due to brake lever hoods becoming much longer, providing a more comfortable hand position "on the hoods." As riders have come to spend more time on the hoods than on the drops, handlebars are typically positioned lower on the bike to keep the riders in similar positions. This puts the drops even lower, and so drop has been reduced so that the drops aren't too low.
Used almost exclusively for track sprints, these curve away from the ferrule almost immediately. This is because the track sprinters do not need comfortable top positions, and to give more room for forearms as the riders throw their bikes side to side in sprints.
Similar to the track bend, for similar reasons. Criteriums are relatively short races with a lot of aggressive riding.
Gravel bars tend to be wider than road bars—whereas 38 cm would be considered narrow for road bars, gravel bars typically start at 44 cm width. Also, while road bars typically place the drops directly below the ramps, or very slightly outside, with gravel bars there is typically a pronounced flare, so that the bars are much wider at the bottom. Furthermore, with gravel bars, the "drop" section of the bars will frequently have an outsweep, so the bars are wider at the very end of the drop than at the start. Gravel riding is still a new discipline, and there is a lot of experimentation in this category.
Confusingly, there are drop bars (typically with a modern ergonomic bend) that have an airfoil-shaped surface for the tops, and these are called aero bars (even though the airfoil surface often interferes with installing clip-on aerobars).
These are similar to Maes-bend bars but with slight upward bends near the ferrule to give the rider a slightly more upright position.
Allow the rider to sit upright on a bike while holding the bars. Also known as upright or North Road handlebars, these are common on cruiser bikes and some comfort bikes. They sweep back towards the rider, with grips that point more towards the back than to the sides.
Cruiser bike with handlebars (Photo credit)
These can sometimes be found at the local bike dump cheaply. Some find them quite comfortable, and they allow a lot of different positions.
Although purpose-made handlebars are generally better, it's possible to make a set of bullhorns by cutting drop handlebars and flipping them over.
Also called tribars. First popularized in triathlons, now used in most time-trial situations where the racer is alone and not able to ride in a group.
Aerobars reduce the frontal area of the rider + bike, reducing aerodynamic drag: they can increase the rider's speed by 1–2 km/h at a given level of effort.
They also give an extra hand position and take weight off the wrists, making them popular with ultramarathon cyclists.
However, control over the bike is more difficult in that position, and there are no brake levers on the aerobar extensions, though shifters can be mounted there. For this reason, mass-start bike races and races where riders draft generally prohibit aerobars.
Aerobars consist of
Most often used in high-level competition, these pair aerobars with a minimal handlebar that is little used, but carries brake levers (as appropriate), gives extra leverage for starts and climbs, and gives better control in corners. Basebars are evolved from bullhorn bars.
Used by those who don't have a dedicated time-trialing bike. Also popular with ultramarathon riders, these clamp onto the ferrules of other handlebars (usually drop bars, but also sometimes flat bars).
Mini clip-on bars do not extend forward of the brake levers. Some events that otherwise do not permit aerobars may permit mini aerobars, such as "draft-legal" triathlons and Paris-Brest-Paris.
One of the more interesting bars I've tried is the Titec H-Bar. There are an insane amount of hand positions. It can be hard to find a good spot for levers and shifters, though.
Here are rebar bars on a rebar bike.
Riser-bars place the rider in a more upright position than completely flat bars and might be better for mountain-bike technical maneuvers such as slow drops to flat (hucking) and just generally lifting the front wheel to clear trail obstacles. (They are still flat handlebars, but are raised at the ends.)
Handlebar width is also important and the trend for mountain bikes seem like they are getting wider. Wider bars give more stability during hairy technical descents, but the downside is that trail side tree clearance is reduced.
As riser bars get taller, the extreme versions would become Ape Hanger bars, which have a parallel in Motorcycles.
These do NOT have a cross brace across the top, so are not BMX bars.
Upsides: some perceived coolness factor, and when riding there's good ventilation to ones armpits. Helpful for finding your bike in a crowded bike park.
Downside: Poor control at any speed and angle of turn. Excessively long brake/gear cables where these are even fitted. Minimal ability to ride out of the saddle. Obstructions if rider is in an accident. Excessive length means they're easily bent. Not particularly good from an aerodynamic perspective. Difficult to park/store in tight spaces. Low speed manoevering is difficult, and is riding under low branches.
Used mainly on BMX / 'Cruiser' BMX Bikes and other dirt track use, with 20" and 24" wheels, respectively.
Frequently accommodate padding on the stem and top bar for when you go over them, and hit precious body parts on the way over.
Very strong, designed to take lots of abuse.
A bull horn setup with an add on so that the rider can ride in a more upright position when on the flats. This seems like a good setup when speed is desired some times but the rider also wants to be able to smell the flowers. You can brake from the top by pulling on the rod.
From: Bike snob NYC
Primarily used for racing, these blur the line between bullhorns and tri-bars/aerobars.
3T pursuit bars.
Lowered bullhorn bars - add aerobars to these and they become pursuit bars.