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View Full Version : Why bull horns rather than drops as a base for an aero bar setup?




RFC
05-06-08, 03:37 PM
I have a dedicated tri bike with bullhorns and aero bars with barend shifters. The combination works fine, but I can't see how it is better than drops as a base. The brakes are as accessible, riding on the hoods is as good or better than on the end of the bulls, and it gives you another aero, secure, riding position.

What am I missing?

Triguy
05-06-08, 07:09 PM
Frontal Area / Aerodynamics. If I recall correctly, a drop bar with brake levers(STIs are reallly bulky) is about 60 seconds per 40k slower than a standard bullhorn with "reverse pull" levers.

i've thought it would be pretty cool if a company offered some sort of drop bar that smoothed things out and shrinkified the frontal area but offered the numerous hand positions of drop bars. Really though, with a flat top, and thinned up drops/brakes it would still be significantly bigger than my Hed Vantage 8 and I would only opt for this type of bar on 1/10 of courses where I was descending/ascending steeply and often.

I think a drop basebar like visiontech used to make is the other option; you get the "drops" position, except you lose out on the "hoods" position.

Rahzel
05-06-08, 09:00 PM
On a properly fitted tri bike, with the "hoods", extensions and pads in the correct place, the "drops" would not be in a usable position--they would be too close to the rider.

Also, aerodynamics, as triguy said. In addition, even a properly fitted "drops" position isn't as aerodynamic as a good aero position. Not to mention that for many athletes, the tri aero position is primarily comfort-based, with the pads providing skeletal support that you can't get in a "drops" position.

RFC
05-07-08, 01:49 AM
This all makes sense. Thank you. Now, another question. As I understand it, you are saying that, by itself, the bullhorn produces less drag than the drop bar and brake, again, by itself. And, the assumption is that the tri rider will be spending the majority of his/her time on the aero bars.

Now, another question, which is more aero, the rider on the drops or the rider on the bullhorn?

Rahzel
05-07-08, 06:05 AM
"which is more aero, the rider on the drops or the rider on the bullhorn? "

Good question. I'd say that the answer depends on the width and drop of the bullhorn setup. Obviously a narrower and lower bullhorn setup (like the slightly older Visiontech integrated model) would be more aero than a wide and flat bullhorn setup (like the common/cheap/perfectly good Profile Airwing bar).

Even in spite of that, I'd make a completely uneducated guess that you're slightly more aero in the *drops* on a road bike, because the road bike is designed more around that position than the tri bike is designed around being in the "hoods".

However, in a tri you should really only be using the "hoods" to get up to speed initially, to get around sharp corners and to stretch occasionally (if it's a long race), so hopefully the increased efficiency of spending 98% of your time in the aerobars will offset the aero losses of the bullhorns/"hoods"! :)

MarkSch
05-07-08, 09:31 AM
This is almost a history of triathlon question!

Back when I started triathlons in the early 80s there were no aero bars....everyone rode their road bike....by the mid 80s many use time trial funny bikes with bullhorn bars....here, the idea was that the bullhorn gave the same position as the drops would give on the road bike, and since you were in a time trial you were going to be in the drops the whole time anyway so didn't need another position.

Aero bars arrived in 1986, with the first versions being a spaghetti shaped contraption meant for regular bikes that gave a drop position AND the aero extension. Clip ons arrived by the late 80's and MOST people added these to their standard drop bars....

Then things got interesting. Folks started playing around the seat position, moving forward and up, and allowing the bars and elbows to be dropped down, culminating in the tri and time trial bikes we see today.

So where is this long winded history lesson going?

For most, the bullhorns are set low enough to approximate a position in the drops....putting a drop bar would put the drops so low as to be tough to useably reach....this in addition to the aero argument

itri-45
05-07-08, 11:26 AM
Now, another question, which is more aero, the rider on the drops or the rider on the bullhorn?

I think it depends on the setup. However, riding on the aerobar will be much more efficient and comfortable than riding on the drops and so you'll be able to go longer and faster.

ModelT
05-07-08, 05:16 PM
...here, the idea was that the bullhorn gave the same position as the drops would give on the road bike...


Thank you. I always wondered why so many bullhorn bars dropped down. :)