They say that if you have a great idea for something new, it’s already been done and can be found on the internet or in the adult film industry. A few months ago the 2×10 drivetrain entered my 135lb, skinny legged, high cadence life. As everyone should know by now, the gear ratios offered with the 2×10 are a little bigger then the 3×9. Which isn’t a big deal to a lot of people but, to me…it’s a small detail that has a huge impact.
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My great idea for something new was smaller chainrings for the 2×10, which is no exception to the “great ideas rule.” At first I commissioned a small machinist to fabricate a 25t little ring to fit my SRAM XX bolt pattern. It was great but, after a while the relationship between the custom Ti little ring and the stock XX big ring seemed to weaken. Shifting suffered, and I found the gap between a 25t and a 39t to be pretty drastic at times. Thinking 25t/38t would be more my style. Did I mention that I’m a picky guy?
So…do I now have two ideas for something new? Maybe not but, it doesn’t matter anyway because it should already exist. Right? Right. Through the tides and waves of the internet, I’m introduced to the Italian company CarbonTi, who boasts a healthy stock of painstakingly well thought out and designed chainrings, bolts, and rotors. Yes, living up to the name, all made from carbon and titanium! Although bittersweet in my case, I find it…a set of 25t/38t chainrings, for the XX crank, that are made to be used together!
The Package with both rings is at my door in a few days (with green chainring bolts to match my bike!).
30 minutes later the installation is done and I’m riding out the door to the trails. The first thing I’m interested in testing out is the shifting from little ring to big. Not to be outdone by the stock XX big ring, the CarbonTi big ring has eight carbon fiber ramps that are recessed and are nestled between numerous smaller ramps milled from the Ti ring itself. Starting in the little ring I shifted back and forth as faster then I normally would, just to give it a kick in the pants. I was shocked at how well it accepted my abusive behavior by almost instantly shifting from ring to ring with a cassette like feeling.
Making my way to trail that I’m extremely familiar with and know how they’re “supposed to feel,” I start to focus on the gear ratio gap between the 25t and 38t. I’m excited about this. The transition from a triple to a double ring set up took some time to get used to and I’m liking the idea of having rings that aren’t so dramatically different, and with good reason. Dropping from the big to little felt closer to what I was used to on my old triple, normal, fast, and not having to compensate much by shifting in the rear. My (VA) hometown trails have a lot of descending that goes straight into climbing so, I’m a pretty tough critic about this.
I’m a bit of a durability snob, so I gave the rings the “Colorado test.” Unquestionably surviving the flight out there, we drive to Fruita and ride the Kokopelli trail and onto Porcupine Rim. If you don’t know anything about Porcupine Rim, just know that after the ride some friends of mine returned their rental bikes with missing pivot bolts and the shop mechanic said “eh…that’s Porcupine!” Needles to say, it was burly enough for me to slam and bend a few chainring teeth on 14 miles of slickrock descending. But it’s true, what they say about the elasticity of Ti. Back at camp I bent the teeth back with an adjustable wrench. Where I’d usually have fear of snapping of aluminum teeth, I eased the Ti teeth back to center. After spinning the cranks backwards a few times, the teeth sprung back so well, I couldn’t find which ones were the ones I bent back.
Virginia has some pretty big climbs, and I’ve got pretty skinny legs. These gear ratios are what’s making it possible for me to have a 2×10 drivetrain and feel good about it.
See it all at http://www.carbon-ti.com/
For other options, check the first post on my custom chainring experiments.