SRAM Force CX1 Cyclocross Group

It was only a matter of time before the 11-speed 1x setup reached cyclocross racers. SRAM recently released their cyclocross specific Force CX1 drivetrain—their first setup tailored for the discipline. With the release come new crank arms, chainrings, brake levers and a rear derailleur. Now that 11-speed wide range cassettes are available paired with a cyclocross specific 1x package, is it time for you to make the jump? The weight savings and simplicity of eliminating the front derailleur is advantageous, but will you be missing out on key gear ratios? Lets break it down and see how it compares to a 2x system.

Weight is one major benefit of the 1x setup. Savings come from eliminating a front derailleur, cable, housing, a chainring and a shifter. Doing a conversion from a SRAM Force 22 road group to Force CX1 is the easiest way to compare. The table below lists the various components, their individual weight savings and the total. Your weight savings will vary depending on your current setup.

weight

Here’s where the weight savings are made: the left lever lacks any kind of shifting mechanism. The CX1 crank arm with a 42T ring was compared to a standard 50/34 Force crankset to find the most substantial weight savings. Positive gains are found by eliminating the front derailleur with cable and housing. Unfortunately, the rear derailleur weighs more than a comparable Force derailleur due to the added clutch system for chain retention.

Beyond the weight savings, the simplicity of a 1x also has the advantage of eliminating potential mechanical issues during a race. With one less derailleur, you have one less item to maintain and worry about failing.  This is especially helpful in a cyclocross race where one little problem can cost you a few places on the results sheet. With wide-narrow tooth designs and rounded chamfers to help prevent chain drop, CX1 chainrings include mud-clearing recesses to ensure that your drivetrain won’t clog up at a muddy race. Available in 38, 40, 42, 44 and 46-tooth options, there is a X-SYNC chainring to suit your needs.

All CX1 chainrings utilize the common 110 BCD compact bolt spacing, meaning they will mount up to any 110 BCD crank arm if you don’t want to upgrade that component.

compacts

Gain Ratios of a 50/34 Compact Crankset with 11-28 and 11-32 cassettes

Comparing a couple more common compact cyclocross gearing setups at right, we see a low-end gain ratio of 2.1 or 2.4 for the 11-32 or 11-28 cassettes respectively when mated with a 50/34 double crankset. A gain ratio is the number of times the wheel will rotate for every single rotation of the crank. When shifted into 50-tooth chainring and 11-tooth cog, a gain ratio of 8.9 is achieved.

cx1

Gain Ratios of an 11-32 Cassette with four different CX1 Chainrings

The 11-speed CX1 setup is compared with all possible front ring combinations mated with an 11-32 cassette. This setup shows a comparable low-end ranging from 2.3 to 2.8 and a high-end from 6.8 to 8.2. Although these combinations are not as wide of ratios as a compact double crank, most of the time it is not necessary in a cyclocross race. While some may appreciate the wider range that a double offers, the beauty of the CX1 system is being able to select a ring that is right for you and the course you are racing on. Even Katie Compton, considered the most successful American cyclocross racer to date with 21 World Cup wins, runs a 46T big ring paired with a 12-28 cassette. If Katie only uses a 7.5 gain ratio at maximum, you will definitely be in the right ballpark with the new CX1 gearing ratios.

So if you are looking to shed some pounds, simplify your setup, change your gearing or all of the above, CX1 is the way to go for cyclocross racers. Although a cyclocross specific group, it is compatible with SRAM road groups, meaning you don’t have to upgrade your entire setup. If you already have SRAM road shifters, it is fairly straightforward to remove the shift mechanism from the left brake lever. Maybe your conversion will start with a CX1 derailleur and chainring, followed by the purchase of new shifters and crank arms later. The flexibility and reliability of the CX1 system leaves you in control.

2015-12-16T16:46:31-08:00