I ride both wide and narrow bars, and have no strong preference. But I do prefer wide bars on some bikes, and narrow ones on others. Most of this was a sidebar in the front-end geometry article in Vintage Bicycle Quarterly Vol. 3, No. 3. Here it is with some details added:
1. Breathing: It is hard to believe that decreasing the handlebar width even by as much as 5 cm (say from 44 to 39 cm) makes a big difference on chest capacity, even if we assume it would restrict breathing (the evidence below seems to indicate the opposite). After all, if your reach is about 62-75 cm, even 5 cm change amount to less than a change in slope of less than 8 percent or 4.6 degrees. So each arm would move inward by less than 2.3 degrees with the narrower bars. Because your arms articulate at the elbows, the angle change at the shoulders can be even less. (The matter is different with modern aero bars, which fix the position of the elbows, and where positions as narrow as 15 cm are possible, with the elbows touching each other.)
2. Steering: Depending on the front-end geometry, some bikes are easier to ride with more leverage (wider bars), while others require only the slightest touch to keep them on course, and thus are fine with narrow bars. Generally speaking, older bikes (1940s) have less trail and require less steering input, thus are fine with narrow bars.
3. Bar position: On low bars, which usually are combined with a less stretched-out position (your arms angle downward rather than forward), you put more weight on the bars. This exacerbates lean steer/wheel flop and all the related issues of shifts in rider position influencing the steering. So wider bars, with a long lever-arm, mean these influences are reduced - a 1 cm shift of your hands results in less steering input.
4. Low handlebars: Regarding the low bars - Fred made a good point. With races being shorter and speeds much faster than in the past, less weight rests on the hands, and multiple hand positions become less important. Coppi and Bartali's racing bikes were set up more like modern randonneur bikes, because they spent significant time on their bikes. If modern racers had similar fitness (some would say, lack of modern doping) as the old campionissimi and rode on the same courses, I believe their bike setup would be similar to Coppi's Bianchi or Bartali's Legnano.
Conclusion: For me, narrow bars work well on bikes designed for them. A 1940s racing bike, with a high bar position and relatively stretched-out position, puts less weight on the hands. These bikes usually have a low-trail geometry that does not require wrestling with the bars. Not much leverage needed here. These bikes are fine with narrow bars, but they aren't much worse with wider bars.
Modern bikes with more trail and a lower bar position react more to shifts in weight. More leverage helps both by minimizing the impact of rider weight shifts on the steering and by offering more leverage to counter wheel flop and bump steer.
Some bikes during the transition to modern geometries, which may still have "old-style" narrow bars, thus may be improved with wider bars.
Overall, I have found that after a few miles, I get used to any bar width, and it does not affect my performance.
When I raced, I used a bike with a modern racing position. Now that I do long-distance rides over a variety of surfaces, my bike setup looks more like a 1940s racing bike...
Jan Heine Editor/Publisher Vintage Bicycle Quarterly c/o Il Vecchio Bicycles 140 Lakeside Ave, Ste. C Seattle WA 98122 http://www.vintagebicyclepress.com
At 8:35 PM -0500 5/26/06, John Thompson wrote:
>Donald Gillies wrote:
>> 5% more breathing capacity with wide bars ?? I can hardly believe it.
>> The chest is a fixed cavity and you breathe by pulling the diaphragm
>> down, drawing air into the lungs. The arms are unable to influence
>> the size of that cavity. The diaphragm is several inches below where
> > the arms are in all riding positions except facing backwards sitting
>> on the handlebars steering with your hands behind your back.
>>
>> I'd like to see a reference to the "so-called" research that purports
>> that wider bars increase breathing capacity ! ! !
>
>The best I can find is that the effect of riding position, and
>presumably arm position, on breathing capacity is "inconclusive:"
>
>
>Medicine & Science in Sports & Exercise: Volume 29(6) June 1997 pp 818-823
>
>Influence of different racing positions on metabolic cost in elite cyclists
>
>GNEHM, PETER; REICHENBACH, STEPHAN; ALTPETER, EKKEHARDT; WIDMER, HANS;
>HOPPELER, HANS
>
>Department of Anatomy, University of Bern, CH-3000 Bern 9; and Institute
>of Sports Sciences, CH-2532 Magglingen, SWITZERLAND
>Submitted for publication January 1995.
>Accepted for publication January 1997.
>
>http://scholar.google.com/scholar?hl=en&lr=&safe=off&q=cache:-zpW-sQrM6wJ:www.ms-se.com/pt/re/msse/fulltext.00005768-199706000-00013.htm+factors+affecting+lung+volume+sports+medicine
>
>
>--
>John (john@os2.dhs.org)
>Appleton WI USA