I asked the folks at Louis Garneau about steering torque testing on their Gennix TR1 tri bike. The reply I got from them was, ďIn theory there is a 23.8% stability increase.Ē There is no testing that demonstrates this or, if there is, I wasnít provided the results.
What is it I was asking for? Whatís my interest in this bike?
Iíve written in the past on steering torque. This is the most important thing you deal with that you donít know anything about, and that there is very little testing on. This is the Dark Energy, the Fifth Force, with which you contend.
Not that itís unknown, and not that itís unmeasurable. Itís that we donít measure it (we should) and we donít think about this when designing or buying new bike frames (we should).
One company did think about it: Louis Garneau. The image below of the Gennix TR1 frame speaks more about what Iím talking about than any description I can give. The drawing yet further below explains the problem.
In the image below we see how most tri bikes are made. Hydration systems, fork surface area, fork nose cones that creep up in front of the frameís head tube, along with aerobars, along with your own body from the shoulders forward, and finally along with the front wheel from the tireís contact patch around the front of the bike and back to the point where it disappears inside the fork blades, is all frontal area that a sidewind hits, twisting everything attached to the steering axis in the direction of the wind.
In the drawing below it's everything shaded green and tan that is subject to the twisting forces the sidewind generates (along with aerobars, and your body). What I hoped I'd someday see is a fork that has surface area roughly represented by the purple area. What I didn't realize at the time I wrote my earlier articles on steering torque is that a bike like this had already been made.
The Gennix, above, attempts to fight this force by building into its fork surface area behind the steering axis. In the image above, of the Gennix frame, everything in the green shaded area sits behind the steering axis. You see all that fork surface area. In the yellow shaded area is that part of the fork in front of the steering axis. This is very different from how most tri bikes are made.
What is that 23.8% stability increase Garneau is talking about? What I think, and hope, theyíre talking about is a reduction in steering torque in a yaw. When the sidewind hits all that mass in front of the steering axis, pushing it one way, one hopes that sidewind will push that part of the fork behind the steering axis in the opposite direction, reducing the torque the rider must fight in a sidewind.
I asked Lionel Sanders about this. I didnít tell him why I was asking the questions I was. No lead-in. No coaching. I didnít reference the bike, or steering torque, or anything. I didnít wanít to color his responses. I said to Lionel, "Iím not going to ask about the bikeís speed, only interested in the way the Gennix handles."
I asked Lionel about his bike, "In windy conditions; on descents in the wind; with various wheels, especially front wheels; compared to other tri bikes youíve ridden, and compared to other athletes riding their bikes in windy conditions like Kona, and how you feel youíre doing compared to how you feel theyíre doing as regards handling tough conditions."
Here is what Lionel said.
"I do a lot of my riding indoors, so the only experience I get is in races. I will say, at Ironman Florida in 2014, it was very windy. With very little experience, I did not find it to impact my bike handling whatsoever. And there were a lot of sections with strong crosswind. My other high wind experiences have been in Kona. I trained there during the race in 2014 and raced it in '15 and '16. In all honesty, I have not really found the wind to effect me much. Of course, it's a pain in the ass, and I would prefer a strong tailwind, but in terms of handling, I haven't really had much problems.
"So much so, that in '15 I rode a Hed Jet 6, and had no issues, so decided to run a Hed Jet 9 this year. Once again, no issues. I definitely would attribute a great deal of this to the bike, as I have very little experience in high winds. The final experience that comes to mind has been the last two years at Galveston 70.3. Both years it has been a very strong cross-wind, in both directions. This year, I didn't even notice it. I didn't really think it was much of a factor, until I looked at the results after and saw that Starky and Weiss and I all biked around 7 minutes into the 4th fastest biker.
"My only real experience of windy descents has been in Kona. The bike rides well even in gusts. Of course, you get the odd gust that scares you a little, or if you are leaning into the wind, and suddenly enter a low pressure area and the Ďwall' is no longer there, that can be a little scary, but overall the bike handles very well in those conditions.
"The only bike I have any memory of is the Shiv. I rode that bike at Muskoka 70.3 in 2013. I will say, it did not handle as well as the Gennix. It wasn't even that windy, but a few times I got scared and had to get out of the TT position. I rode a Zipp 808 and Zipp disc in that race. As well, many times I looked back at the rear wheel thinking I had a flat, because the back end was not very stable with the disc.
"I usually only look at the better bikers, and they often have far superior handling skills than I do, so it is tough to say. It's also tough to tease out how much of the differences in windy conditions are due to handling, and how much are due to the fact that in windy conditions it is usually a much more individual bike ride. From what I can see, in comparison to most athletes, the wind does not effect me as much. Kienle on the other hand is a far superior rider in windy conditions than I am. But for the most part, I don't think I give up much in high winds, and I attribute a great deal of that to the bike.Ē
Lionel of course is sponsored by Louis Garneau. Readers must factor that in. Heís also, however, refreshingly honest, and is always that way. Factor that in.
What Lionel says above does not constitute a test, rather an impression. Still, I found it illustrative and I hope our industry will find the will and the way to test steering torque. I hope readers note what Lionel said above: ďÖin '15 I rode a Hed Jet 6, and had no issues, so decided to run a Hed Jet 9 this year. Once again, no issues.Ē This might mean that a fair test between bikes is to normalize for steering torque. If you can ride a 90mm front wheel on a bike, and only a 60mm or 40mm wheel on another, this might vault one bike to the front of the aerodynamic pack.