lee_rimar

Looking for unbiased reviews from someone who has actually used them. Anyone here have first-hand experience with them, or pointers to articles with test results that were *not* sponsored by the manufacturer or resellers?

cb400bill

Look weird.

rosefarts

There was a guy, possibly he made this company, that’s had something like this for years. His were more prominent, they extended down to maybe half the wheel.

I’ve read his justification. It totally makes sense. I’m not fast but I am vain. I could never justify them.

squirtdad

jan heine does similar but not as big


Wheel Fairings

At gravel speeds and with gravel tire widths, aero wheels and bladed spokes don’t make much sense, but we can improve the wheels’ aerodynamics in other ways. The top of the tire moves at twice the speed of the bike. (The bottom grips the road surface, so it doesn’t move at all relative to the ground.) Let’s say you descend at 36 mph (58 km/h)—the maximum I reached on the gravel of Unbound XL this year. At the top of your tires, the tread slices through the air at 72 mph (116 km/h). Wind resistance goes up with the square of speed, so tire treads at 72 mph have four times as much wind resistance as they would at 36 mph.

That’s where the Rene Herse’s fender fairings come in. (They may look like shortened fenders, but they are not intended to keep the rider dry.) By shielding the tops of the tires from the airstream, they reduce the wind resistance. Now the airstream is hitting the fender fairing—which moves at 36 mph—rather than the tire at 72 mph. We optimized the shape of these fender fairings in the wind tunnel, until they decreased air resistance by 1-2%—almost as much as a set of aero wheels on a racing bike. In road racing, fairings are illegal, but these rules don’t apply to most gravel races.
If you have doubts about the aerodynamic benefits of fenders, look at a Moto GP bike. The 2022 Suzuki above has fenders shielding the tops of the tires. The coverage of the Suzuki’s and the Rene Herse’s fenders is almost exactly the same, if you factor in the effect of the fairing at the bottom of the motorbike’s rear wheel. (It’s nice to see that our wind tunnel tests and those of a well-funded Moto GP team show the same results.) Do these fender fairings really provide a benefit? Moto GP teams spend a huge amount of time in the wind tunnel, and they wouldn’t add parts to their bikes that don’t provide measurable benefits.

lee_rimar

Was that 1%-2% of the drag for the entire bike+rider facing the wind? Or just what was generated by the wheel itself?

squirtdad

Not sure

he also suggests narrower handlebars, non flapping clothing and that possibly the handle bar bags acts in a minimal way as a front fairing

the whole article is an interesting read link to article https://www.renehersecycles.com/aero...-gravel-bikes/

lee_rimar

Thanks, I had already looked that up and it was interesting. I may try to make my own short fender fairings.

But I'm still looking for anyone with genuine experience of that nullwinds product also.

shelbyfv

Y'all missed April 1 and 4/20 both.

squirtdad

fraid not and they are sold out https://nullwinds.com/collections/al...12838287704167

hidetaka

Great news! While the ÆroDefender is sold out, spoke fins are still available!

CrimsonEclipse

Good until crosswinds?