Installed my fender extender from project D. No more spray from the wheel going into the lower radiator and on the engine.

Where did you get the fender extender billy? I wonder if it would do as good at keeping stuff from getting tossed into the radiator and damaging it. Would this be as good as a radiator screen or guard? Sprung weight or unsprung weight, which is worse? Doesn't look like it weighs much.

Would this be as good as a radiator screen or guard?

how does it attach?

David here is where I got it (from Taiwan) http://projektd.com/index.php?osCsid=ca4d6fb4dda777ea057d9c9ee9478244
Just a small piece of plastic, weighs very little. Came with 2 adhesive strips on the piece and screws. I was not going to use the screws that would look like crap so I used the adhesive strips it came with and epoxy. Super easy and fit like a glove. I thought I paid 30 bucks for it but its listed at 29 euros which is a bit more. A lot for a piece of plastic but then again it was perfect fit. I drive to work a lot and often rain or shine and there was a water mark on the lower radiator where it was constantly getting sprayed, now I don't have to worry about that or small stones coming off the wheel.

It would take a lot of time to make something yourself and not be as nice. $30 is a good price. I have not tested Amazing Goop

http://www.zoro.com/amazing-goop-all-purpose-adhesive-squeeze-tube-clear-140211/i/G6213383/?utm_source=google_shopping&utm_medium=cpc&utm_campaign=Google_Shopping_Feed&gclid=CjwKEAjw8LOsBRDdub-swPW8riISJAAnmS01yXL-edyEvmtohh2gr7J9U6MP-iQi2DM_TrireSX8URoClDvw_wcB&gclsrc=aw.ds

Hub swears by this suff and he has gooped a lot heftier items than a fender extender to his bike. No bolt snecessary, you cannot pull it off. The way you remove it is to grab the goop with a needlenose and roll it off. I've seen videos of adhesives of this type and I'm pretty impressed.