OneUp Components 42T Sprocket, Narrow Wide Chainrings and RADr Cage Review

by Brian Mullin on March 18, 2015

Upgrade your 10-speed cassette to an 11-42 or 11-40 wide range cassette with the OneUp Components 40T/42T sprocket and use their new cage replacement for Shimano derailleurs that dramatically improves shifting performance for a low-cost 1×11 alternative.

The 11-speed drivetrain blazed like a rocket into the mountain biking world when SRAM released their 1×11 XX1 system around two years ago. SRAM’s system uses various front chainrings (28T-38T) combined with a 10-42T cassette for its 1×11 gearing. The price tag and the requirement of mostly using a full set of SRAM parts for the drivetrain have kept many people from enjoying its simplicity, lighter weight, and wider gearing. It didn’t take long for third party companies to give consumers workarounds for the 1×11 system, and the most prominent design retrofits an extended range cog onto a normal 10-speed  cassette.

42T Extended Range Sprocket

The OneUp 42T or 40T cog fits at the end of the Shimano SLX, XT and XTR, SRAM X5, X7, X9 and X0 11-36T cassettes. To complete the set up you remove the inner 17T and 15T cogs and replace it with the kits included 16T cog, which keeps it as a 10-speed system. The larger cogs utilize 7075-T6 aluminum, weigh around 70 grams, and have 12 upshift points around their circumference for shifting purposes. To help prevent the cog from digging into the soft material of most freehub bodies, it has wide tabs by the spline for a better load distribution. The 16T cog uses Chrome plated hardened steel and weighs 18 grams. It works with 1×10 and 2×10 drivetrains, comes in black and green and costs $90 for the 42T and $85 for the 40T, and includes a 16T replacement cog.


  • 11-13-16-19-21-24-28-32-36-42
  • 11-13-16-19-21-24-28-32-36-40

Narrow Wide Chainring

Their new Narrow Wide Chainrings had a profile to prevent chain drops, crud chamfers for mud shedding performance and extended ring life and reinforced wide tooth design for durability. The 7075-T6 aluminum chainrings, have a 104 BCD spacing, come in black and green, and cost $53 for the 30-tooth and $47 for the 32 and 34-tooth versions. The 30T has integrated shims with chainring bolts threads for spacing purposes to prevent the chain from interfering with the crank spider.

RADr Derailleur Cage

Their second generation RAD derailleur cage, known as the RADr, was designed for Shimano Saint and Zee systems, but works with all Shimano Shadow+ rear derailleurs. Just like its brethren the RAD cage, it dramatically improves shifting performance on any extended range Shimano 1X10 drivetrain. The RADr or Radial Appositioned Derailleur cage design has moved the upper pulley wheel rearward of the cage pivot to optimize the derailleur for larger sprockets. When the derailleur moves into larger sprockets, the top pulley wheel automatically moves away to adjust the chain gap. The RADr uses 7075-T6 aluminum, includes front and rear replacement cages, weighs 34 grams, comes in black and green and costs $55.



I pulled the XTR cassette off the rear hub and removed the 17T and 15T cogs and the accompanying spacer, and replaced them with the OneUp 16T cog. I then slid on the 1mm OneUp spacer and their 42T cog, and then the rest of the new XTR stack, and cranked it down to specs. I liked that the OneUp cog had a small arrow pointing at the notch, so it made it easy to line everything up on the freehub body. Swapping everything out increased the cassettes weight by approximately 50 grams.

Derailleur Cage 

I disconnected the chain and unscrewed the SLX derailleur from the frame, but left the derailleur cable and housing connected. Turned off the clutch mechanism and removed both pulley wheels and the inner cage. Unloaded the cage tension and removed the stopper pin, and squeezed the cable guide and bolt knuckles together and rotated the cage 180 degrees clockwise. Removed the clutch cover and loosened the clutch bolt releasing the outer cage and spring and washer. Grabbed the OneUp outer cage, inserted the bolt from the kit and the old washer, and inserted the hooked end of the spring into the non-XTR hole. Holding the entire assembly together placed the other end of the spring into the derailleurs corresponding hole and tightened the bolt. This step is the only tricky part, as things can get out of alignment and allow the spring to move around, requiring a reassembly. Using wrenches on either side of the clutch mechanism, tighten everything down, put the clutch cover on and retention the spring by rotating the cage 180 degrees counter-clockwise. Finally, add the stopper pin, pulley wheels, and the OneUp inner cage.


It was a bit tricky getting the 30T chainring up and over the spider on my e*thirteen cranks, but after some convoluted and frustrating maneuvering I got it into position. The threaded integrated shims made attachment easy using the appropriate length chainring bolts, and the spacing offered a good chain line and no interference issues with the spiders arms.

Final Set Up

I bought a new 120 link SRAM PC 1071 chain and ended using 112 links plus the PowerLock connector. It worked fine for both the highest and lowest gearing options on my derailleur with the 42T rear and 30T front combination. The RADr redesign meant it didn’t require a drastic B-tension screw adjustment though it was slightly farther out than normal to keep inner pulley from interfering with the large cog. I had to do some minor barrel adjustment for the derailleurs cable tension to get the things shifting smoothly, and it was ready to ride.


For mechanically inclined individuals, it’s easy to install the RADr cage on a Shimano derailleur, and I even did it with the shifter cable still attached. Once I had installed the RADr cage, I turned the b-tension screw out a couple of turns past normal compared to the original 11-36 positioning. It was not out anywhere near as far as a non-RAD cage Shimano or SRAM derailleur would require, which can produce clunking shifting in the smaller cogs. Building and attaching the 11-42T was simple, as was adding the narrow wide chainring though it was tricky maneuvering it over the spider. Some minor tweaking of the barrel adjuster might be needed to get the shifting running smoothly, although it shouldn’t need much.

After a few months and many miles on the bike, my conclusions are that the RADr cage is a significant addition to their 16T and 40/42T extended range system, and it drastically improves shifting performance. It provides crisper, smoother and faster transitions in any gear, and it was especially noticeable down in the previously problematic lower cogs. The design repositions the upper pulley with the cage pivot, and the synergy of a more normal B-tension setting, closer functional pulley positioning, and chain wrap, produces greater performance throughout the gearing spectrum. In direct comparison to the original 32T to 36T upshift, there is a slight loss of smoothness going to the 42T, and a bit more of a thunk during the 19T to 16T drop.

Their narrow wide chainring has performed admirably, and I haven’t suffered any dropped chains, significant wear or poor shifting issues. Their 42T extended range cog has worked like a champ, and the shifts up and down to it have been more than adequate, and it hasn’t shown any overt wear and tear.

Bottom Line

I think this simple system, with it’s low-cost and fewer part swap outs will appeal to a lot of people. The $200 price and maybe a new chain will get you a pseudo alternative to the XX1/X01 1×11 wide range of gearing. This set up is obviously dependent on you owning a Shimano Shadow+ derailleur. In direct comparison to the SRAM 1×11 system, it lacked the exacting precision and smoothness of that drivetrain. The difference wasn’t that significant in the grand scheme of things, and the RADr cage helps jumps thing up a notch in performance.

The OneUp Components RADr cage for Shimano derailleurs and their 40T/42T extended range cog and narrow wide chainring make for an excellent low-cost alternative to a full-fledged 1×11 system. The RADr cage makes such a drastic improvement in shifting performance, that I consider it a requirement for the proper functionality of the 40/42T extended range system.


  • Wide range 1×10 gearing – XX1/X01 range
  • Low-cost: $187-198, ER 40T/42T $85-90, RADr cage $55, NW chainring $47-53
  • Improves shifting over standard 11/40 or 11-42 system – especially lower cogs
  • Better chain wrap
  • More normal B-tension
  • 1x and 2x usage
  • 1x – Weight saving, depending on components used, anywhere from .6 to .75 lbs


  • Only Shimano+ derailleurs, no SRAM version
  • Not quite SRAM 1×11 precision – but very close
  • Clunky 19T to 16T shifting
  • Missing 10T cog of XX1/X01 cassette

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