Is running a FLO 90 on the front and a FLO disk on the back too aggressive for IM 70.3 Augusta? Or any race, for that matter. Tried to get 90/90 front and rear last sale but were out of 90 rear. Have ridden this combo outside in training twice now. First time was fine, second time was on a fairly windy day and felt unstable.
so my questions are:
would any time gains for increased aero be offset by increased friction from wind blowing the bike all over the place? I’ve ridden the disc with a 30 mm Oval wheel on the front and it felt fine.
For those with lots of experience riding deep wheels, I feel like I’m getting pushed around by the wind, but does this represent a safety risk? Understand may not be easy question to answer. I have ridden mountain, road and tri bikes all my life, so I feel that my bike handling is pretty decent. Thanks for any input.
I ride a FLO 90 and Disc for all races. Hilly or not. Sometimes the front can get twitchy in the wind but never been too bad. Keep riding then and get more confident in the wind.
In many situations, the front 90 will be quicker. An instance where it isn’t is if you have to get out of aero to maintain control of your bike.
The rear disc will virtually always be faster, and shouldn’t cause an issue with handling unless you’re a feather
^^^^^This.
Always run the disc. Unless you are quite light, the 90mm front should be manageable. It just takes some getting used to. Go out and train on it for a few weeks to get the hang of it and you should be good in anything but Kona-esque winds.
I’m racing Augusta as well and will be on a Zipp disc and 808 front. I always run this combination. I weight 150 and it does push some in the wind but it is manageable.
Also doing Augusta. Also will, and almost always do, run a 90/disc. I’m only 135lbs and don’t have issues. I get pushed by the wind but you learn to handle it and trust the bike. You will be fine.
There is a blanket assumption that a deeper section wheel is faster. That’s not always right.
I was corrected on this assumption by the late Steve Hed before his tragic passing and by former Cervelo engineer (now Cannondale) Damon Rinard.
The deeper section 90mm front rim may be more aerodynamic (key word: “may”), but it may not be *faster. *
In the complex and dynamic conspiracy of overall speed that is wheel weight, turbulence, cross wind stability and drag coefficient a very deep wheel like a 90mm front may be slower overall, especially if the rider can’t maintain a high enough average speed overall to generate a net benefit.
I agree with everyone that a rear disk in likely the best solution across a wide atmospheric and terrain variety; a disk is fastest.
But in the front 90mm is very deep. That means it is very heavy. That also means it presents a significant surface area to crosswinds, potentially affecting steering stability. If a rider is unnerved by crosswind turbulence with a deep section wheel they may “back off” the pedals without even realizing it. They’d be faster on a shallower wheel.
When Steve Hed and Chester Kyle, among others, did early research on optimal rim depth for bicycle speeds they made the first deep section aero race wheel. It was about 60mm deep. It’s likely Hed and Kyle, et al, landed on this aspect ratio as a result of some assumptions and some research that made the 60mm depth the convergence of best wheel weight (climbing and accelerating), stability and drag reduction. It wasn’t until some time later that much deeper (80mm and 90mm) rims hit the consumer market.
When I’m in doubt, I go shallower. And I never go deeper than 60mm in the front.
There is a blanket assumption that a deeper section wheel is faster. That’s not always right.
I was corrected on this assumption by the late Steve Hed before his tragic passing and by former Cervelo engineer (now Cannondale) Damon Rinard.
The deeper section 90mm front rim may be more aerodynamic (key word: “may”), but it may not be *faster. *
In the complex and dynamic conspiracy of overall speed that is wheel weight, turbulence, cross wind stability and drag coefficient a very deep wheel like a 90mm front may be slower overall, especially if the rider can’t maintain a high enough average speed overall to generate a net benefit.
I agree with everyone that a rear disk in likely the best solution across a wide atmospheric and terrain variety; a disk is fastest.
But in the front 90mm is very deep. That means it is very heavy. That also means it presents a significant surface area to crosswinds, potentially affecting steering stability. If a rider is unnerved by crosswind turbulence with a deep section wheel they may “back off” the pedals without even realizing it. They’d be faster on a shallower wheel.
When Steve Hed and Chester Kyle, among others, did early research on optimal rim depth for bicycle speeds they made the first deep section aero race wheel. It was about 60mm deep. It’s likely Hed and Kyle, et al, landed on this aspect ratio as a result of some assumptions and some research that made the 60mm depth the convergence of best wheel weight (climbing and accelerating), stability and drag reduction. It wasn’t until some time later that much deeper (80mm and 90mm) rims hit the consumer market.
When I’m in doubt, I go shallower. And I never go deeper than 60mm in the front.
Good job besmirching their good names to insinuate that they believe your drivel about wheel weight.
For those with lots of experience riding deep wheels, I feel like I’m getting pushed around by the wind, but does this represent a safety risk?
I am riding 1080 rear or disc and 808 front and when I first rode deep dish wheels was pretty alarmed when I rode them in windy conditions. But over time I’ve become accustomed to this and it’s no longer a problem. Riding with a really strong crosswind I was actually leaning the bike at quite an angle into the wind. I’d imagine in this instance something like a 30mm would be quicker than an 88mm, leaning into the wind didn’t feel particularly efficient way of riding. But I think for the most part, it comes down to getting used to how the wind affects the movement of the bike. There’s only really been one occasion where I felt the need to slow down because of the wind and that was down a steep hill with 30km/hr crosswinds. Perhaps there’s a bit of an urban myth going around about deep dish wheels? But then I’ve never had a bad accident, so perhaps I’d feel differently about them if I had?