Over the past few months, BikeRadar has gleaned bits and pieces of information on the new SRAM X01 groupset, through early launches of 2014 bikes. Today SRAM has unveiled complete details, including pricing and claimed weights, for its second tier 11-speed mountain bike drivetrain.
X01 and XX1 crankset comparisons
Like the SRAM XX1 crankset, the new X01 has carbon fiber crank arms. The primary difference between the two sets is their bolt circle diameter, or BCD. The X01 crank uses a slightly larger BCD than XX1, making the chainrings the only items that aren’t cross-compatible between SRAM’s two 11-speed mountain bike groupsets.
According to SRAM, the 76mm BCD rings and spiders used on XX1 are significantly more expensive to produce. To keep the price in check, SRAM opted to use a simpler and easier-to-produce 94mm BCD for X01. The aluminum X1 cranks we’ve seen specced on 2014 bikes such as the Scott Genius LT 700 650b also share this 94mm bolt pattern.
You’d also better start working on your hill intervals, as there will be no 28T chainring option for the new group. X01 chainrings sizes will be 30, 32, 34, 36 and 38.
While we’re on the subject of chainrings, it appears that SRAM has taken note of the growing number of companies (including Race Face and e*thirteen) producing aftermarket chainrings with a stepped tooth profile similar to the X-Sync design.
Not one to sit by and lose out on sales, SRAM will offer X01 level chainrings in the very common 104mm BCD pattern. This should be good news for riders looking to piece together a 1x drivetrain using cranks they already own.
SRAM’s X01 and XX1 cranksets have different bolt circle diameters
Claimed weight for the X01 crankset (with BB30 bottom bracket and 32T chainring) is 655g, a 5g increase over XX1.
X01 shifters – nothing to see here
There’s not much to report on the new SRAM X01 shifter; all the pertinent technologies carry over from XX1. The X01 trigger uses the same cable pull and has the same ZERO LOSS design, allowing you to fire off successive shifts with ease. The X01 shifters are also MatchMaker X compatible.
The primary difference is that the XX1 shifter has a carbon cover, while the X01 version uses an aluminum shield that allows access to the shift cable and other internals. Claimed weight for the X01 trigger shifter is 91g.
All SRAM X01 components will be available with red and white trim or grey on black
The story with X01 Grip Shift is similar, the so-called SPEED METAL indexing and ball bearing design carrying over from XX1. Like the X01 trigger, the X01 Grip Shift uses aluminum in place of carbon for part of the lever body.
Claimed weight of the X01 Grip Shift is 143g (including handlebar clamp cable, and lock-on grip).
XX1 and X01 derailleur comparisons
The X01 groupset’s one and only derailleur shares the technologies that make the XX1 model the most critical piece of the 1x puzzle.
The X01 derailleur has two 12T pulley wheels that spin on cartridge bearings. The upper pulley is offset to maintain proper spacing between the chain and cassette as the chain moves from one end of the cassette to the other.
The two mechanisms that keep chain slap to an absolute minimum – the horizontal parallelogram design and roller bearing clutch – are also present. The construction of the derailleur body appears to differ slightly, although the X01 model does get a carbon cage.
Claimed weight for the X01 rear derailleur is 252g.
All the critical technologies carry over from XX1 (R) to X01 (L)
XG-1195 cassette – new black lasts longer
Perhaps the most noticeable component in the X01 group is the blacked-out cassette (we’d call it stealthy if it weren’t for its massive size). The black color comes from a surface treatment intended to extend the life of the cassette. SRAM claims this is less costly than the coating used on XX1.
Cassette range is the same as for XX1: 10-12-14-16-18-21-24-28-32-36-42. SRAM claims the manufacturing process is identical to that for the XX1 cassette. Both start life as a block of 4130 chromoly steel and are CNC’d into a 10-speed cassette. The massive 42T cog is constructed from aluminum and press-fit onto the cassette via 16 mounting pins to complete the 11-speed sprocket.
Given the difference in price and the 11g weight increase, it’s likely that manufacturing of the X01 cassette (right) is expedited by milling slightly less material from the cassette body as well as by a more affordable surface hardening treatment
Not surprisingly, X01 uses the XD driver body. A list of companies offering wheelsets compatible with this design can be found at www.xddriverbody.com.
Claimed weight for the XG-1195 cassette is 275g.
PC-XX1 chain - same chain for both 11-speed groups
We've been told by SRAM that both the XX1 and X01 groups will use the same 11-speed chain. The 11-speed chain previously used for XX1 had cutouts in the outer plates to shave weight. The new PC-XX1 chain does away with these cutouts.
Claimed weight for the PC-XX1 chain is 252g.
The new PC-XX1 chain (top) will be used on both XX1 and X01 groups. The 11-speed chain previously used for XX1 had cutouts in the outer plates
SRAM X01 US/UK/European pricing
X01 cassette, 10-42T, 11-speed
PC-XX1 Hollow Pin chain, 118 links, 11-speed
X01 cranks (chainring and GXP cups not included)
X01 Grip Shift, available in black or red with locking grips
X01 rear derailleur, available in black or red
X01 X-Sync chainring 30T
X01 X-Sync chainring 32T
X01 X-Sync chainring 34T
X01 X-Sync chainring 36T
X01 X-Sync chainring 38T
X01 X-Sync chainring 32T 104BCD
X01 X-Sync chainring 34T 104BCD
X01 X-Sync chainring 36T 104BCD
X01 X-Sync chainring 38T 104BCD
We’ll have to wait until we get our hands on a compete SRAM X01 group to find out how the claimed weights stack up against those of XX1 in the real world (curiously, several of the claimed X01 weights are lower than our actual XX1 numbers). For now, at least, it appears that the marginal increase in the weight of X01 is offset by the reduction in price.
Performance should be quite similar to that of XX1, given the fact that the drivetrain’s critical technologies – the X-Horizon rear derailleur with SRAM’s Type 2 Roller Bearing Clutch, X-Sync tooth profiles, and the 10-42T cassette – have all carried over to X01.
While still a high-end group with a substantial price tag, X01 promises to bring 1x11 performance to a broader audience. And if the recent development of 1x specific mountain bike frames is any indication, both of SRAM’s 1x11 groups will be extensively featured on mountain bikes in the coming years.
This raises the question of whether SRAM will continue to adapt its 1x11 technology to the more affordable X9 and X7 levels. SRAM spokespeople wouldn’t comment on the possibility, but given the company’s level of investment we’re optimistic that the 1x11 trickle-down will continue.
X01 is already available on select 2014 mountain bikes; it will be available aftermarket by mid-September. For more information visit www.sram.com.