SEA OTTER CLASSIC 2010 – FSA had one of the few, perhaps only, real game changer* product release at Sea Otter. Debuting under their Metropolis line of street products, their new Patterson Transmission crankset uses an internally geared planetary drivetrain that provides an effective 42T chainring to complement its physical 28T ring. The big news? It requires no frame mounts or modifications.
What this really means is that come NAHBS, Oregon Manifest and Int’l Framebuilders Expo (formerly the San Diego Custom Bicycle Show) next year, I’m betting you’ll see this on many, many bikes. Why? Because combined with an internally geared rear hub like, oh, say Shimano’s forthcoming 11-speed Alfine, you could get a 22 speed bike with nary a derailleur in sight! If FSA makes it available with a carbon belt drive gear, which FSA mentioned is in development, you’d be looking at a relatively bomb-proof commuter and city bike drivetrain that would appeal to a lot of folks.
Sound interesting? Click more for details and photos…
Like Truvativ’s HammerSchmidt, the Metropolis PT crankset uses internal gearing to change the drive ratio from 1:1 with the 28T to 1.6:1 to simulate a 42T ring, and shifts are instantaneous and effortless, even under load.
FSA’s version is meant for commuter-type use only, not mountain biking. The only requirements for use are a standard 68mm bottom bracket shell and downtube front derailleur cable runs.
The cable runs down the tube and directly to the inside of the crankset. Normally, the ring runs in cadence with the cranks for lower gearing. When shifted, it essentially engages the pawls that are turn the internal gears and provides for 1.6 gear turns per crank rotation.
Where HammerSchmidt relies on ISCG tabs to mount to the frame so it doesn’t rotate, the Metropolis PT setup simply has a plastic arm that swings into the chainstay to prevent rotation of the entire unit. It’s a simple solution that opens up a lot of opportunity for people to install on existing frames. In fact, FSA says installation is so easy, an experienced mechanic (home or shop) could probably put one on and have it working in about 20 minutes.
Because the internal pawls retract completely when disengaged, the system runs very quiet and the unit will shift with pretty much any two speed shifter. FSA did caution against using it with shifters that snap the gears too quickly, though, as they could basically trick the system into not shifting or something like that. Sounds weird, but they’ll have a compatibility chart when it becomes available.
Speaking of which, it’ll be spec’d as OEM on complete bikes first, then hit the aftermarket at the end of the year. Look for MSRP to be around $300. Weight is around 1,500g (about double high-end racing cranksets, but not too far off low-end commuter sets).
FACTOID: The Patterson Drive is the brainchild of Sam Patterson, who worked at SRAM for 14 years and helped develop the original Grip Shift products. He doesn’t like front derailleurs.
The brushed aluminum finish of the PT crankset will match the Metropolis mustache handlebar and a new matching stem and seatpost (not shown).
*You could argue that the Shimano’s 3×10 Dynasys or SRAM’s 2×10 X0 and X9 groups are gamechangers, but in our opinion the 3×10 is an evolution, a good one, and the 2×10 was all but foreseen for those two groups having already been announced on the X7 group.
