My research consists of 21 years of riding dropbars off road (since 1985) for everything from XC racing to trials to DH. I have tried many other not-straight bars over the years and test ridden bikes with various straight bars.
Why it works for me:
- My wrists, elbows and shoulders are in a position that allows my arm to effectively absorb impacts and reduce shock transmission. With straight bars my joints lock out. Straight bars hurt me. Drops do not.
- Because of the mobility of my upper body I can adjust to impacts and maneuver more easily.
- Most of my riding is done deep in the hooks of the bars. Impacts and bumps drive the bars into my palms increasing my hold on the bar without needing a vice-like grip. On a straight bar the same impacts try to rip my thumbs off as my hands move forward.
- I can easily use one or two fingers on the brake levers with ZERO reduction of grip on the bar or control loss.
- I have a greater range of motion in the cockpit. Not locked into one position. More mobility = more able to shift body weight = more control.
- Stability, carving and flickablity. I feel like I am riding IN the bike rather than on top of it. Much easier to control.
- Flared drops increase comfort and control compared to road drops.
- Flared drops have better tree clearance than wide straight bars.
- Drops give me a couple of other hand positions for climbing and just cruising on the flats. Not relevant for this discussion.
For off road use drops MUST be setup properly. An off road drop has less reach and less drop than a road bar. It is wider with the ends flared at 10-30 degrees. Made with thicker walled tubing.
A short reach, high rise stem is usually necessary. The hook of the drop should be in about the same position as the grip of any other bar (use the location of your thumb and index finger as the reference point). It does not matter how the hand gets there. Just matters where it is.
Disadvantages for me? Just a couple:
- High center section reduces clearance (I do have a full face helmet and a stem pad).
- Generally heavier than a straight bar setup
- More limited brake choice (though I have no complains with the Avids).
Not a setup for everyone. I do not claim it to be.
Most parts used on mtbs were used in the beginning because they were available.
Swept-back cruiser bars were not strong enough in the late '70s. BMX bars were too tall. Motorcycle bars were available and strong. Other choices are available now (Jones HBar, On-One Mary) as people realize mtbs are not motos.
Most riders use what they learned with and what is widely available. Rarely do they try anything other than minor variations on the theme.
Do you have any RESEARCH that shows that straight bars are better?
Not that it would make me switch. I have found the bars I like.
"Why not just use a mustache bar so you do not need the tall stem?"
I have tried mustache bars, Jones Hbars and other similar bars (see the North Road bars I tried on my SlingShot, since reverted to the dropbar setup). None give me the same ergonomics of a flared dropbar.
It is not just the backward bend/sweep or the flare of the bars that is important. The vertical bend of the drop is the key.
Look at the pics to the right. My hands are in the same place: Deep and forward in the "hook" of the bar. This is the most secure grip position on the bars. I feel "in" the bike and the brakes are most easily used (see point #3 above).
No other bar shape has the secure hook/drop.