When we built our collection of Calfee bikes I opted to leave off the paint and clear coat as a way of freeing myself of being overly concerned with protecting our painted frames from nicks and scuffs. For the most part, it’s been a great choice.
However, owning a Calfee or any other composite-framed bike frame that has an au natural finish is similar to owning a bike with polished aluminum cranks from daVinci: they ain’t no maintenance, just low maintenance. For example, if you don’t wipe down your daVinci cranks after a ride to remove any sweat or sports-drink residue, the chemicals in that residue will leave marks in the aluminum that can’t be wiped away the next day. Moreover, the longer you let those sweat spots sit the harder the stains, or worse, the etching will be to remove.
With unpainted composite frames, it’s UV light that can play havoc with the finish. You see, while UV light won’t weaken the frame, it will give the exposed epoxy that binds the carbon fiber fabrics together a yellowish tint over time UNLESS you keep the frame coated with a UV protectant. Calfee recommends the use of Aerospace 303. Aerospace 303 is great stuff, if you don’t follow the application instructions and buff-off any residual material it has an undesirable side effect: when it gets wet that residual material begins to run and leaves an oily blotchy or streak film.
I will note, the prior owner of Debbie’s Calfee Luna Pro clearly didn’t get treated with Aerospace 303 on a regular basis and does show signs of yellowing epoxy. And, I’ve also been a bit lax in retreating our Calfee tandem on a regular basis so it has some spots were exposed epoxy has yellowed. Again, these are cosmetic issues, just know the cause / effect relationship if you have or are considering a “nude” Calfee frame.
On the bright side, Aerospace 303 does give the unpainted carbon frame a much darker hue and satin sheen which is pretty nice looking and seems to have a compounding effect, i.e., the more applications you make the more deep and satiny it becomes over time.