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General Category >> Technical >> Fender stiffness improvement?
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Message started by FlyingLaZBoy on Jul 6^th, 2009, 6:08pm

Title: Fender stiffness improvement?
Post by FlyingLaZBoy on Jul 6^th, 2009, 6:08pm

I posted this in the Ride Reports section, but thought I'd put it here, too... any thoughts on reducing lateral "wagging" back and forth of Planet Bike plastic fenders at high speeds???

http://i53.photobucket.com/albums/g73/flyinglazboy/fenders.jpg

The front fender has a ~8" long unsupported extension past the frame attachment tab, and when I would hit ~20mph or so, or into a heavy wind, this section vibrates back and forth like crazy... . When I got home and took the fenders off, it looks like the edges of the fenders had been contacting the tire sidewalls whenever they vibrated like that, because the sidewalls were discolored with whitish dust (ghosts of fender use past, from the inside of the fender.). If that's the case, I'm glad I didn't blow out a sidewall!!!!

I actually had the "front" fender on backwards, to give more coverage toward the front, and the extension closest to me was vibrating -- and when it's on "regular", that same section vibrates when it's pointed forward. Any thoughts on how to eliminate this effect on Planet Bike plastic fenders? Cut away the "cupped" edges in that section, to reduce air capture?

Title: Re: Fender stiffness improvement?
Post by bob wand on Jul 7^th, 2009, 12:35am

I had this problem on my Trike (Catrike Road) not so much from speed but from chipseal.
It was so bad the rear fender broke in half.

I solved the problem by adding extra stays to the front fenders and a extra set when I replaced the rear fender.

Those cupped edges adds stiffness to the part even tho it's not its main function.

Bob Wand