- Your chain, cassette, and RD are probably already toast
- Makes a single-ring setup more practical
- Less chain slap and fewer dropped chains
- More momentum and smoother shifts while climbing
- Having one more is always a good idea
Like most folks, we're skeptical about the real benefits of the latest and greatest product innovations. So when Shimano launched their 10-speed MTB drivetrain Dyna-Sys back in 2010, we wondered what one more cog could possibly offer aside from a page of new SKUs and a big ol' headache. But two years hence, we've put it through the paces and have come back singing its praises. But what exactly makes it so great?
First, there's a lot more to it than just one more cog. Shimano did a significant re-work to the whole rear of the drivetrain. The centerpiece is the giant 11-36 cassette. Not only did they cram another cog onto the 9-speed freehub, but they reshaped the tooth profiles to help the chain transition more smoothly from cog to cog. With less of a gap in ratio, the chain is able to engage the next cog more quickly. This allows the rider to carry more momentum by staying on the gas and spinning their ideal cadence through a wider range of terrain. It’s a big advantage climbing, especially on the steep power ups. We noticed making climbs in the middle ring that we’d normally have to granny.
The chain was also redesigned to make the inner and outer plates directionally specific. The outer plate was reshaped to get better engagement with the shifting ramps on the front chainrings for quicker and cleaner shifts to the bigger rings. The inner plate follows the same idea, offering more solid engagement with the ramps on the rear cog for quicker shifts up the cassette. It’s a small detail with big benefits.
Shimano also reconfigured the rear derailleur with sleeker cable routing and stiffer springs. The new cable routing eliminates the need for the big loop of housing entering the derailleur, so the housing is much less likely to get caught up in sticks and brush. Stiffer springs mean more responsive shifting, less chain slap in the rocky rooty stuff, and fewer dropped chains bombing the downhills. Overall, the chain control is the best we’ve seen from any derailleur system.
Dyna-Sys is now available in a range of price points, from Deore through XTR. To make the jump, you’ll need a chain, cassette, rear derailleur, rear shifter, front derailleur, and chainrings. Good news is it fits right in with your old 9-speed crank and front shifter. But Dyna-Sys also makes it more practical than ever to drop some baggage and go to a clean single-ring setup. With a 32-tooth up front and a 11-36 in the rear, you’ll have the ideal range for ripping it up on the North Shore.
