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May 2019

Handlebar width and safety

by John S. Allen

This month’s Safety Corner looks into how a bicycle design difference which might seem unimportant can affect safety. Case in point: handlebar width.

Some very successful mountain-bike racers, notably Jacquie Phelan – earlier a road racer – prefer mountain bikes with drop bars, but the norm with mountain bikes is long, straight, flat bars. Mountain bikes are generally friendlier to beginners than road bikes; flat bars don’t need as much getting used to as drop bars, one reason for the popularity. There’s also a macho element: “I’m big and strong, and I have big, wide, strong handlebars.” I have seen mountain bikes with handlebars as long as 27 inches. Mountain-bikers who often add bar-end extensions, which strike me as a complicated way to achieve a simple result.

Now with today’s clamp-on handlebar stems replacing quill stems, handlebars are held very tightly, but what point is there though in having enough handlebar leverage to pretzel the front wheel if it gets caught in a a slot between rocks? You would crash anyway. Very wide handlebars also give me a sense of poor support, that my upper body is about to fall down into the middle.

I’ll admit that it took me a couple of years, back in the 1970s, to become comfortable with drop bars and enjoy their advantages in aerodynamics, power production and stability. Adopting the posture of a grazing animal with the head extended forward requires strengthening some muscles which otherwise don’t get much use. Stability with one hand on the handlebar is better with drop bars – with one hand on the forward curve of the handlebar while leaning the bicycle slightly the other way I can comfortably make hand signals with the other hand. A higher or closer hand position with other types of bars results in what I call “tiller steering” – unsteady: placing weight on a handlebar end steers it away.

I attended the Northeast Bicycle Club’s Introduction to Racing workshop a couple of years ago. The practice drills are targeted toward paceline and pack riding, but are instructive for any cyclist. One drill has two cyclists riding along side by side on a grass surface and actually leaning into each other. Elbow to elbow, or shoulder to shoulder, that works.

But, if handlebars tangle, the bikes steer out from under, and down you go. If the end of a handlebar strikes a stationary object, or one that is slower, the wheel will steer in its direction, tilting the bicycle in the other direction and dumping the rider. If something faster strikes a handlebar end, the bicycle dumps the rider toward the faster object, which could be another cyclist, or a motor vehicle.

Two common types of car-bike crashes occur in this way: dooring, and sideswipes.

If the end of a handlebar nicks an opening car door, the bicyclist is flung away from the door. If another vehicle is passing, the bicyclist is flung against or under it. That, tragically, ended the life of Dana Laird, a talented and courageous Tufts University graduate student of international relations. She escaped Tiananmen Square in Beijing by way of the Trans-Siberian Railroad, only to die a senseless death in Central Square, Cambridge, Massachusetts. Her long mountain-bike handlebar nicked the opening door of a Honda CR-V SUV and she went under an MTBA bus.

Similarly with Amanda Phillips, who went under a landscaping truck in Inman Square. Most dooring incidents don’t result in such tragedy, though they can easily result in a broken hip or collarbone. Doorings are 20% of car-bike crashes in Cambridge, 12% in Boston, 20% in Chicago. Don’t ride in the door zone – but it’s easier to avoid with shorter handlebars.

A bicyclist whose handlebar end is sideswiped is dumped toward the overtaking vehicle and may go under it or fall in front of the next one in line. I’ve read of examples of this, and many years ago, I had a sideswipe crash. Fortunately, there was no next car and I was wearing a helmet. I walked away with bruises and a broken collarbone, and replaced the helmet.

A handlebar-diversion crash can also due to a fixed object – or on a shared-use path, when passing, being passed, or head-on. I have read CRW member Bill Widnall’s account of the recent fatality on the Minuteman path in Lexington. Bill was out for a training run and had the misfortune to arrive on the scene a couple of minutes after the crash. An eyewitness told Bill that the bicyclist who survived had pulled out to pass and tangled with the other one. It takes only the very ends of the handlebars touching in a head-on encounter to throw both riders over the handlebars. Bill doesn’t recall how long the bicyclists’ handlebars were, but longer ones do make contact more likely.

Very narrow handlebars, with only enough room for a hand each side of the stem, are popular with fixed-gear fashionistas in San Francisco, but don’t provide very good control. You can check this out for yourself on any bicycle by placing your hands near the center of the handlebars. You want to be able to spread your hands farther apart, and not only because that is where the brake levers are.

I find that most flat bars and riser bars are unnecessarily long. And when they have any kind of bend, it may not be practical to shorten them by much, because the brake levers can only go on so far. I’ll get out my hacksaw and shorten flat bars, but I find myself preferring drop bars even in the city, now that I am used to them, for all the reasons I have given.

A happy medium length is in my experience, the traditional handlebar width with road racers, 40 to 44 cm, and a bit shorter for a person with narrow shoulders. This gives good control, and opens the chest enough for free breathing. I find that it works to have slightly wider handlebars on a tandem -- the steering is heavier. But still, I find that 44 or 46 cm is enough.

You pays your money and you makes your choice, as the saying goes, but you may have to do a bit of searching to find flat bars or riser bars that can be shortened to an optimal length. Be safe out there!

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