With a single chainring and only one derailleur on the drivetrain, the availability and proliferation of 1X shifting (pronounced “one by”) has dropped the weight and increased the performance of mountain bikes. Now getting a bike set up with this format is finally affordable thanks to SRAM’s announcement last week of its $900 X1 component group.
The X1 group includes rear cassette, crankset, chain, rear derailleur and shifter. The special chainring teeth combined with the clutched rear derailleur work together to ensure the chain to stays in place without a chain guard.
You can buy the system starting in June. It’s a budget alternative to the two other one-by shifting group sets SRAM sells. The X1, at $900, costs hundreds less. It weighs about a half-pound more, and is different because it’s made with less expensive production methods and materials.
Here at Gear Junkie, we’ve got a sizable graveyard of front derailleurs piling up as we continue to move towards this simpler and lighter format.
For riders without mountains out their back door, the move is a no-brainer.
The term 1X refers to the lack of a front derailleur. With just a single front chainring, the only gear choice is at the rear cassette. SRAM popularized this format by debuting the XX1 group, highlighted by its rear cassette with huge range of rear cogs, from a minuscule 10 tooth to the gigantic 42 tooth. XX1 expanded the rear cassette in both directions — previously the smallest cog on any mountain bike was 11 teeth, and the largest, 36.
The popularity of the format has spawned successful startups like Wolftooth components, whose products enable affordable 1X conversions. (We awarded Wolftooth and SRAM for 1X products at the end of 2013 in our https://gearjunkie.com/gear-of-year-2013“gear of the year” article.)
Now, with the X1, SRAM answers with a sincere attempt at affordability, promising the same performance at more than 30% reduced cost. Lets break it down:
First, the X1’s rear cassette does not use a single CNC’d block of steel, like the XX1 does. Instead, a “Mini Cluster” of just the three smallest gears are machined from a single block a steel, the remaining 8 cogs slide separately over the hub body in a traditional manner. What kind of a difference are we talking about? A cost savings of $132 and a weight penalty of 65 grams. As for performance, SRAM reports that it should be the same, as the gear teeth and chain interface remains identical.
As for the shifter, it is only available in trigger format (no grip shift) but is cross compatible with XX1 and the group inbetween, the X01 (indeed, the naming system could be improved).
The X1 cranks are aluminum instead of carbon. The same goes for the derailleur cage, aluminum instead of carbon there. So although the weights of each part increase a bit, the form and function are the same.
In sum, total weight for the X1 group is 1,750 grams, whereas the XX1 ($1,500 and up depending on shifter and bearing options) weighs in at 1,473 grams. There is a group in between, the X01 group (about $1,300) which weighs in at 1,525 grams. But the story is the price, this new X1 groups costs $900.
So the X1 system is a great value as we are getting the same performance, a weight penalty of just under and just over a half-pound respectively, for a cost savings of $400-$600. It’s tough to justify paying $2 per gram under any circumstances — even weight weenies (like myself) often draw a hard line at $1 per gram.
So, as the trickle down of technology from XX1 continues, we will see X1 drivetrains hung on bikes in the middle price ranges rather than just pro level builds. If it were me building them, I may hang this stuff on top level bikes as well, and put the money towards other upgrades, like better wheels or, better yet, less time in the office.
—Tom Puzak
