Not too long ago, Trek introduced a new blend of their proprietary OCLV Carbon for high stress areas on mountain bike frames and dubbed it appropriately, OCLV Mountain. In testing, the OCLV mountain frames supposedly fared better in an anvil strike test than aluminum or regular carbon frames. However, regardless of how well any carbon tests in a laboratory setting, there seems to always be naysayers afraid of carbon’s unexpected failures based on anecdotal evidence of a friend of a friend who’s frame simply “let go without any warning.”
So, in order to protect their frames even further from impact damage, Trek introduced Carbon Armor – a polymer based “shield” affixed to key areas of the frame more likely to be damaged. While Carbon Armor passed the test in Trek’s impact testing, out on the trail it still manages to raise a few eyebrows as to its actual efficacy.
So here’s the scoop: it works. Period. I had the fortune (or misfortune) of testing out the Carbon Armor on my 2011 Fuel EX 9.8 in what would likely be the worst case scenario and it passed with flying colors. Better yet, after the impact left the Carbon Armor with a fairly large hole, a call to Trek revealed that Carbon Armor is replaceable with almost zero tools. It’s easy enough that almost anyone can do it.
Read on to see what causes a breach in the Armor, and how to fix it!
Before we get into details, it’s important that I point out that this particular frame has seen over a 1000 miles with many, many rock strikes to the downtube, and surely there were many more that went unnoticed – all without any damage to the Carbon Armor or carbon itself. The event that broke through the Armor was a peculiar incidence that I couldn’t repeat if I tried. While blasting down a rocky decent littered with Limestone slabs, I came up on a section that I’ve ridden hundreds of times with a little double drop. Normally, you simply sit back and float through it like a rock skipping through water. This time was different.
Somehow, at full speed my front wheel pushed down the front edge of one of the large, jagged, sharp Limestone slabs, causing the back edge of the slab to lift just high enough to impact squarely with the middle of my bike’s downtube. Due to the momentum I was carrying, the impact with the downtube drove the front edge of the rock into the ground, and caused the whole thing to become a fulcrum that lifted my entire bike off the ground only to come crashing back down after the rock had flipped over. Somehow I managed to ride it out, and without giving it a second thought, I continued the ride. It wasn’t until later that day at the trail head that I noticed the damage to the Carbon Armor – a perfect little triangle was peeled back like a tin can. Honestly, I didn’t expect to find good news under the surface.
However, I was happily surprised to find absolutely no damage under the Armor to the carbon. Zero. As you can see in the picture, the Carbon Armor is ripped completely through but it must have absorbed enough impact that by the time that it reached the carbon to not cause any damage. Not even a scratch.
Afterwards, I continued to ride it for weeks, eventually deciding the flap of exposed Carbon Armor bugged me enough to do something about it. After some investigation it looked like it would be an easy part to replace as it is held in place with two inmolded posts and a strong adhesive backing. A quick conversation with Trek confirmed this to be true, and replacement parts were on their way. I say parts, because the downtube section of the Carbon Armor is included in a kit that includes a new chain stay guard and two seat stay Carbon Armor sections as well. The kit is to replace the Carbon Armor bits on 2012 models, however the downtube and chain stay guards fit my 2011 Fuel EX 9.8 perfectly. The kit, Trek Part Number 428454, retails for $29.99.
Trek did change the shape of the Carbon Armor from 2011 to 2012 by narrowing the tip where it meets the bottom bracket. It seems like this would offer less protection, but from my observations this is to improve adhesion of the piece near the bottom bracket. Due to the shape of the down tube where it met the edges of the Carbon Armor on 2011 frames, the edges would start to peel after a year allowing dirt to get stuck in the adhesive. The new shape seems to fit better with less chance of peeling around the edge. The new Carbon Armor is also thicker, bumped up to about 2.4mm from the previous 1.8mm. Whether it’s due to the increased thickness or a change in material, it seems that the new pieces are more stiff as well. All of which should add up to even better protection of your frame.
Removal of the old Carbon Armor and installation of the new piece couldn’t be easier. Really, the only tools you will need are Finishline Speed Clean, Finishline Super Bike Wash and Isopropyl Alcohol and some clean rags to remove the adhesive residue (and mud and energy drink residue) from the frame. If you don’t have one or the other, you can try other cleaners, just make sure they are safe for use on carbon.
Start by gently peeling back the damaged Carbon Armor. It’s easiest if you start from a point that has started to peel up, though you can easily use your fingernails to start at a corner. Try to lift the adhesive backing along with the Armor, this will cut down on clean up of the down tube later. Peel slowly, and at an angle somewhere between 45 and 90 degrees – this ensures it all comes off cleanly and in one piece without damaging the paint.
Once you have removed the Carbon Armor, you will have a naked down tube with some adhesive residue, and if you’re like me, a lot of mud caked to GU Brew and Roctane residue. Cleaning and prepping the surface for the new Carbon Armor is probably the most important step of the whole procedure. I started by removing all of the mud, drink mix, and other organic bits with the Super Bike Wash. After a thorough scrub with the pink stuff, all that’s left is adhesive residue which Finish Line’s Speed Clean makes quick work of. Spray it on the rag and gently rub the surface until any sticky bits are gone.
When you’re finished, you should have a squeaky clean down tube you can see yourself in. Time for a final wipe down with a new, clean rag and the rubbing alcohol. You want to be absolutely sure there are no oils or residue on the surface that might keep your Carbon Armor from adhering properly.
Peel off the backing strip from the new Carbon Armor, being careful not to touch the adhesive to prevent oils from your skin interfering with the bond. Use the two locating pins on the Armor to locate the position on the downtube (narrow end pointing towards the bottom bracket). If both pins are inserted into their holes before the Armor is stuck to the frame, you will guarantee proper alignment.
Start working the Carbon Armor onto the down tube from the center of the locating pins. I used the ball end of a 6mm Allen wrench to gently make sure the pins were pushed all the way into the frame. From there, work your way from the middle of the Armor outwards, to keep any bubbles or wrinkles from forming.
The finished result is a down tube protector that looks brand new. If you were on the fence about how much benefit Carbon Armor really adds, for me it’s hard to deny it after going through this process. The carbon frames are proving to be tougher than I ever imagined, and Carbon Armor seems to be the icing on the