Hands On: OneUp’s Cassette Changing, XX1 Challenging 42t Adapter Sprocket
Judging by the amount of traffic the release of OneUp’s 42t cassette adapter garnered, people are interested. Specifically people who want to explore the world of wide range gearing for 1x (or even 2x) drivetrains without having to shell out the cash for the upgrade to XX1 or X01. By eliminating one of the gears from a standard 11-36 10 speed cassette, OneUp made room for their 7075-T6 aluminum 42t sprocket – effectively turning the cassette in an 11-42. Costing less than other options, the OneUp sprocket looks like a promising alternative to get the lower gearing you crave, but how will it stack up?
Install notes, actual weights, and more, after the break!
As covered in our first post, the OneUp ring has 12 shift ramps machined into the surface to help the chain jump from the 36 to the 42t. Laser engraving on the ring tells you which side to place the OneUp spacer, so it’s pretty hard to mess it up.
As for the weight, the 42t sprocket itself comes in at 71g with an additional 2g for the needed spacer. Subtract 20g for the 17t cog and spacer and you get an added 53g for a total cassette weight of 390g with a Shimano XT 771 10 speed cassette.
All mounted up the cassette looks pretty normal (with the exception of the obvious green ring) – it’s only when you look closer you may notice the missing 17t. Installation was extremely straight forward, just follow the instructions for removing the 17t cog and a spacer, and make sure to position the OneUp spacer according to the directions printed right on the sprocket. Mount the rest of the cassette as normal, and you’re done.
To prevent the sprocket from digging into freehub bodies, the OneUp is built with wide spline tabs – quite a bit wider than the steel 17t cog that came off.
When it came to adjusting the derailleur, I’m honestly surprised at how easy it was. Somehow I expected it to be more involved to get it to shift properly, but I was happily mistaken. After adding the necessary two chain links to accommodate the bigger gear, the only other step was to adjust the b-tension screw. Realistically, it was more like bottoming out the b-tension screw, but there was just enough adjustment to clear the big teeth without issue on my Pugsley.
I’ll be testing the ring out on a few bikes, but I’m especially excited to try this out on the Pugsley. Ditching the front derailleur on my fatbike was great at first offering no chance of the chain rubbing on the tire, fewer parts to freeze up, and lighter weight, but after I started doing more techy rock crawling type riding, a lower gear would be nice. I’m hoping this is the little bit extra I need to go along with the 30t WTC front chainring.
Certain frames may require some of the additional steps outlined on OneUp’s Site, since it is pretty close. I would suggest lengthening the chain first before trying to shift into the biggest gear due to the fact that if your chain is too short, the derailleur cage will catch on the sprocket and not function properly.
The $100 sprockets will be shipping out at the start of 2014 if you get your orders in now. When asked about the $100 pricetag, OneUp noted that as the part size goes up, so does the cost of CNC machining. Bigger billets are needed with more machining time needed to mill them down to spec.
We’ll report back this afternoon with first ride impressions!