4 years ago10,000+ Views
Impact damage is a carbon fiber bicycle frame's worst enemy. That being said, there's quite a few products available on the market designed to protect carbon fiber and minimize any damage should the inevitable impact occur. Carbon, unlike various metals, does not have a known stress limit or provide clear signs of impending failure. Carbon can and if damaged, will, fail without notice. The best way to protect yourself, because having your frame, forks, or rims fail while you are riding is potentially deadly, is to regularly check your bike for impact damage and to use some sort of impact protection in the areas most prone to damage. The biggest cause of frame damage on carbon road bikes is ironically from the down bars swinging around and hitting the upper frame tube. From there both carbon mountain bikes and road bikes are at risk from damage caused by the tires spitting little rocks and road/trail debris into the seat stays, chain stays, down tubes and forks. There are a few types of protection products on the market. The first is applied like a sticker and consists of a self-healing polymer skin, much like the type used to protect cell phone screens. The other is a spray-on product that also is self-healing. I used an automotive product by Armor All - designed to protect automotive parts from impact damage and scratches. Applied through an aerosol spray can (like the type used for spray paints), this product is called "CUSTOM SHIELD". THE RUN-DOWN: Custom Shield is designed to spray onto plastic, metal, and rubber parts. It is 100% safe for finished carbon fiber - if your bike has a paint scheme in either matte or gloss finish, it'll be fine to use. It applies wet but quickly dries to form a "skin" layer over the item being protected. To remove it, simply find an edge and roll the product back away from the edge and then peel it off. It is supposed to last for up to three (3) months. It costs $15.99/can - one can will provide 2 - 3 full coats over an entire bike frame. *** I purchased the can used for this product test from Pep Boys Automotive Parts - it was on sale and I paid $7.99 US. ------------------------------ PROS : It works. Since applying the Custom Shield protective skin my bike has taken several hits from rocks and ONE hit from an unknown object - I assume it was a rock or a bolt or nut of some sort. In each instance where my frame was struck, the skin was marred or damaged in some noticeable way. This has provided me a clear "map" of where my frame needs the most protection. It is easy to apply, but I'd recommend using a respirator/breather, nitrile gloves, and a well-ventilated area when applying. You will also want to ensure you do NOT touch the frame until the application is completely dry. Image 2 of this card is of me holding the product up, preparing to apply it. Note I wore eye protection, a respirator, and gloves. It's practically invisible, although it has a distinct texture and will make your bike appear "glossy" if it is a matte finish. Images 3 and 4 of this card show the product after it has dried. There is a glossy "orange peel" texture to it. It is water proof and dirt does not stick to it. Oils and grease however will, but will wipe off easily with a wet sponge - see cons for "being careful while cleaning". It is affordable - but depending on how often you ride, the 3 months stated by Armor All for its life expectancy may be a stretch, especially if you are a mountain biker or trail rider. CONS : Requires a fair amount of prep to properly coat the frame. This means it takes a dedicated cyclist to want to remove most of their bike's hardware to get the frame "naked" for application. When cleaning, you must be very careful not to dig in too hard or you will easily tear the skin. Image 6 of this card shows what happens if you rub too hard to remove an oil or grease stain. This is what this product looks like if you tear it. Once the skin is torn, it will start to peel and the tear will only become larger. At this point the only option is to reapply. *** Because this skin is self-healing - to a point - once it is in it's liquid form applying a new layer to heal a damaged one is easy to do. It is a protective layer but does not disperse impact energy as some of the layered "peel and apply" skins are. Likewise, the peel and apply skins require you cut them to shape and they are quite thick. This applies easily, in wet form, and is relatively thin. It has proven to tear easily with a strong impact or with forceful rubbing (to clean grease off of it). Image 5 of this card is a mark left from the impact of some unknown item... I heard the frame get hit but didn't see what had done it. I assume it was a rock. The frame WAS protected, but the skin tore. Images 7-9 are places where the product is simply wearing off on it's own. The chain stay areas make a lot of sense to me for they are constantly hit with small dirt and sand particles from the chain. __________________ BOTTOM LINE : For light use or application in areas of your bike where you expect there to be less risk of impact, this product is ideal. For heavy use and situations where you expect regular impacts with rocks, etc... I'd recommend one of the peel and stick solutions. I'll be testing the peel and stick product called "Shelter" by Effetto Marioposa next. I hope this was helpful! Have a great ride!
Great review by the way, it's not often we see someone go into so much detail around here.. I've used something like this for my car before, it's called Plastic Dip, and I can't stand the peeling! That being said, I think we should think about why someone would use this in the first place. I feel that the coating is really only going to help considerably when it comes to small dings like rocks flying up and hitting the frame. Carbon frames are strong as a whole, but they are susceptible to small, focused impacts. In many stress tests carbon often meets or exceeds the testing done to aluminum. A rock or anything else has the potential to do a few things in damaging your bike. First, it may chip the paint. Second, it may crack the resin coating of the carbon. Third, it may penetrate and/or damage the carbon fibers. The first two are completely fine and safe, the third is what will eventually cause your carbon frame to break. I am under the impression that if the impact is great enough to damage the actual fibers, a small layer of coating isn't going to save it. That's just my .02.
Awesome write up. For someone like me, in a winter climate this seems ideal. I would personally use this for mountain bikes, cross bikes, or a bike used for commuting in poor weather conditions. If I lived in a more tropical area I think this would be more of a hassle than it's worth.
@TeamWaffles - true... And the product reviewed won't really do anything more than protect the frame from small impacts - gravel, road debris, etc... The next protective product I'm going to test is a military-grade multi-layer polymer skin - it absorbs the force of an impact and disperses the energy through its layers. Really cool stuff. I'll share a video where they test this material by coating a florescent light bulb (tube) with it and then use a pendulum device with a hammer attached to test the newton forces this material can withstand. It's impressive. I agree that carbon fiber is very strong. In the bass guitars I play there are two pulltrusion process carbon fiber rods in the guitar's neck for support. These rods are the same strength of a steel rod the same size, at 1/3 the weight. The issue is that carbon fiber lacks the molecular bonds that metal does - where any form of tempered metal will always fail at a certain force, reliably, too many variables in the carbon fiber manufacturing process make it impossible to predict the fracture point of any two carbon fiber items. A ding that doesn't damage on frame may seriously damage and compromise the next. Because of my work in the music industry with manufacturers I've been around several "factories" - more like workshops - that build carbon-fiber musical instruments or parts. I've held raw CF weave and followed the process to a finished instrument. And it is amazing stuff. Likewise, quality control of the few larger manufacturers in Taiwan who make the majority of the CF frames in the world - Giant - makes Giant, Trek, Bontrager, Colnago, Scott , Fuji - Dorel Industries makes Cannondale, Pacific, GT, Mongoose, Schwinn, Iron Horse - There's just a few high quality carbon frame makers who make nearly 80% of the carbon frames sold in bike stores in the USA. But if I told you that the majority of different guitar brands for sale here in the US are made in one of 3 factories in Korea - LOL... it's all the same really.
The only issue with it for me is that it is pretty easy to tear. And once a tear starts, it's like sun burnt skin - it just keeps peeling. Now an alternative would be to tape off your frame in certain areas - and not coat the entire frame like I did. Then you've got protection where you need it most and if - for instance - the down tub portion tears, it's not going to eventually pull the section on the upper tube off. That sort of thing. I'm excited to get the 5m roll of the "Shelter" product. It's the same intelligent polymer - self-healing impact absorbing material the ZAGG invisible shield screen protectors are made of.