Thursday, July 14, 2011

Flaccid Fender Frustrates Former Fan

I am many things, but a math whiz is not one of them. Still, even though I haven't seen the inside of a geometry textbook since the days of tight-rolled jeans, I know just enough about triangles to know that something's wrong with this picture:
Yes, it's sideways. And yes, that looks like the wheel of a kid's bike. But look again. Spot the design flaw hinted at in my alliterative title? Look at where the fender stays attach to the fender itself. Based on a (very) rough measurement, there's about 12 inches of fender and mudflap hanging out beyond the stays... which is about half of the total length of the fender. That's half a fender with no support. The result? Every little bump sets off an oscillation in that dangly end, causing the thing to rattle like a neglected Huffy.

The worst part is, the purveyors of this fender aren't dumb people. This is a Planet Bike, supposedly designed specifically for the Swift Folder (it lacks the cheesier -- ATMO -- hardware of the PB Recumbent fenders, so I don't think it's just one of those repurposed... although, dangitall, that cheesy hardware would have made it much easier to fix this problem now that I look at it). I have two other sets of Planet Bike fenders in the fleet in different diameters: 26-inchers on the tandem and 700c-ers on the tourer. Both have about 7" of unsupported length on about 28" of total fender... which is to say 25% dangle-factor rather than 50% (Yes, I fudged my measurements a little to make the math easier. I'm an English major.) And both can tackle washboard without sounding like I'm playing the washboard (danger, noisy link to a band I'm obsessed with).

When I feel motivated, I'm probably going to drill out the rivets, move the bracket down near the end where it belongs, and plug up the remaining holes. But I shouldn't have to.

(Just to soften the blow: The rear fender installed quite nicely and is rattle-free, since it has three equally-spaced support points around its diameter. And although I resisted the instructions telling me to just zip-tie the chainstay bridge mounting point, I have to admit that they were right -- my attempt at a no-zip-tie kludge was much less elegant, so I gave in to the Zen of Zip.)

1 comment:

Anonymous said...

yeah, there's definitely a problem with the location of the fender stay attachments. As a user of the PB 'bent fenders, there's something to be said for being able to select where the stays attach (which is what their weird hardware permits). The downside is that the little mounting gadgets can't grab the fender stays very well. I've actually had to knurl the stays and use a bit of JB Weld to get the fender stays to actually stay in the mounting gadgets. Yeah, nothing's perfect!

I'd suggest moving the bracket that the stays mount to. Some stainless bolts and stop-nuts should do the job nicely, and some packing tape or other material can cover up the holes where the bracket formerly resided.

Planet Bike does offer some handy products, but they still make dumb mistakes.

from pleasant Peoria,

Steve K.

p.s. why does Google still try to make me open a blog account when I have a regular Google account?? I can't sign in without opening a blog account, so I have to sign in as Anonymous. Google seems to be suffering from rectal-cranial inversion lately.