[CR]Fenders and cross-winds

(Example: Events:Cirque du Cyclisme:2002)

Date: Wed, 18 Jun 2003 09:31:05 -0700
To: classicrendezvous@bikelist.org
From: "Jan Heine" <heine@mindspring.com>
Subject: [CR]Fenders and cross-winds

Bill,

I have experienced the same cross-wind problems on bikes that weren't designed for fenders (Rivendell, Mercian), especially if they also were equipped with a handlebar bag. However, Singers don't seem to suffer the same way, even with the handlebar bag. Something about head angle and fork rake? I don't know enough about bike geometry to determine, I just know that some work better than others.

As far as fenders slowing me down - I doubt it. I think any effect is too small to notice. But my times on a given course with racing bikes and with randonneur bikes don't seem to vary much. Nor are people on state-of-the-art racing bikes able to drop the randonneur bikes on longer rides.

However, as I said, the evidence is based on hearsay. Anybody got access to a wind tunnel? I can provide a bike with what I think may be aerodynamic fenders (photo at http://www.mindspring.com/~heine/bikesite/bikesite/rivrando.html). Then we could also determine whether the handlebar bag also reduces the wind resistance, acting as a fairing (illegal for UCI races!).

As far as the increase in frontal area that Grant Mc Lean mentioned - that is negligible for the front, if the fender fits well, and none for the rear. (The seat tube is fatter than the fender.) And a more aerodynamic shape often has a bit more frontal area (like a teardrop that beats a smaller cube in aerodynamics.)

Jan Heine

P.S.: Isn't this fender topic slightly OT, and more suited to some bicycle tech or randonneuring newsgroup.

Bill Bryant wrote:

Strong side winds or passing trucks shake the front end of the bike more with fenders than without. Like Curt, I would like to see the proof from Jan about his claim. After 30+ years in the bike game I have never heard this one before.

Bill Bryant
Santa Cruz, CA