To answer your first question, no this is NOT normal. Although Ceramic Coatings are not Kryptonite, they are very durable when applied PROPERLY. I repeat, PROPERLY. The fact that you can take your nail and scratch the coating off of the substrate indicates to me that the coating was NOT applied PROPERLY. In your case, if rocks are flying at your pipes at 55-75MPH you’re bound to get some marks, but it shouldn’t be flaking off anywhere else.
The two most likely causes for what you’re describing are:
1) Improper substrate cleaning / preparation
2) Improper material / cure cycle
We’ve been in the Performance Coating business offering both High Temp Ceramic Coatings and Powder Coatings for close to 15 years. Our area of specialty is Performance Motorsports, which could include anything from a 5hp mini bike up to the Worlds Fastest 10.5 twin turbo Shootout Car making 4000HP+. Based on your description, I’d be willing to bet that the prep is insufficient. In that “Black Ceramic Coating” has become pretty popular for various bikes over the last few years, pipe makers have taken some of this work in house. In order to get Ceramic Coating to stick to your pipes we would burn them in a furnace at about 650F-850F for about 5 hours. This destroys any mandrel oils, greases, etc. From there they are profiled / blasted with a specific media based on the type of Ceramic being used. At this point your parts are being treated as if they were being prepped for open heart surgery, CLEAN, CLEAN, CLEAN!!!!!. After profiling they are sprayed and baked accordingly.
Most pipe makers DON’T have the time, man-power or capability to prep the pipes properly. They’re in the pipe building business, not the coating business. In many cases they may wipe them down or try to scuff them with scotch brite but this usually doesn’t hold up very long. The other thing we see a lot of is, YOUR Ceramic Coated pipes were previously a set damaged or blemmed CHROME pipes. So now prepping chrome is even more critical than that of raw metal pipes so this doesn’t usualy end well either.
If the manufacturer or dealer will warrantly them, give it a shot. If not, we’d be happy to help you correct the problem. Below are a couple recent Vulcans pipes we’ve done as well as pipes from a few other bikes……We offer about 12 different colors of Ceramic Coating and most of those are rated at 2000F+ so there are no worries of over heating the pipes or coatings.
Hope this helps,