SRAM's successful campaign to eliminate the left shifter also doubled the amount of wear and tear on the one chainring that now has to shoulder the burden of every pedal stroke. Worse yet, the switch to smaller chainrings puts more pressure on the sprocket teeth. Add the regular use of exaggerated chain angles and you'll get a perfect recipe for rapid sprocket wear. No secret there. Three rides in and the anodizing will be carved off half the teeth of most aluminum narrow-wide sprockets.
SRAM has a simple and very inexpensive solution to that wear issue - one that cassette makers have known for years: steel sprockets. SRAM's long wearing X-Sync Steel chainrings are available in 30 and 32 tooth options in its 94-millimeter bolt circle, and a direct-mount 28-tooth chainring is offered in SRAM's most popular 6-millimeter offset. All three use the crank's existing hardware and cost around $20 USD.
Trail Report X-Sync Steel Details:
• Material: Stamped steel
• Finish: Black
• Compatibility: all SRAM one-by cranks (direct-mount and 94mm bolt-center-diameter (BCD)
• Warning: Direct-mount 28 is not compatible with BB30 cranks that require a zero-offset chainring
• Sizes: 28-tooth direct-mount w/6mm offset, 30-tooth 94mm BCD, 32-tooth 94mm BCD
• Weight: 110g (32t), 96g (30t), 133g (28t direct-mount)
• MSRP: $19.99 USD
• Contact: SRAM
Installing the 94-millimeter BCD chainring does not require the mechanic to remove the left crank arm, which makes the job quite simple. The steel sprocket only cradles half of the chainring bolts, but everything cinches up well. As mentioned, SRAM's stock hardware interchanges with the steel sprockets.
Switching out the chainring to the 28-tooth direct-mount necessitates removing the crankset - also a simple task, as SRAM's left-side arm in self-extracting via an eight-millimeter Allen key. To install the 28t, simply slde the bottom bracket axle out, unscrew the three Torx 25 screws that retain the crank spider, and replace the spider with the X-Sync steel sprocket. Any home mechanic who is familiar with bike basics should have no problem installing either option.
Under power, the steel chainrings are marvelously quiet. I spent most of the test time riding the 30-tooth, as that is my preferred gearing, and also because I could switch it out without removing the crankarm from the bike. After the better part of a month on a wide variety of trails and a spate of rain and mud, I can report that the chain never jumped the chainring and, while some of the black finish is beginning to show signs of wear, the steel teeth remain unaffected. With equal time and similar conditions, the aluminum X01 chainring was aleady showing flat spots on the outer faces of the teeth. Pinkbike's Take:
|Riders willing to trade weight for durability should be quite happy with SRAM's steel chainring options. So far, they are out-wearing aluminum rings well over two to one (by my estimate) and at one fourth the cost. Comparing SRAM's lightest aluminum direct-mount chainrings with the steel options is a bit sobering: the XX1 28t is only 66 grams, while the lightest (overall) steel direct-mount 28t option weighs 133 grams. Consider the value, however, and a longer-lasting, 20-dollar chainring makes a lot of sense for riders on budgets, or for those who suffer bad weather and routinely grind 90-dollar aluminum sprockets into paste. I'm a fan. - RC|