Looking for the wide range performance of XX1 but can’t afford the price tag? At OneUp Components they believe in working less and riding more which is why they came up with a solution to that very problem. As their debut product, OneUp is essentially giving your cassette an extra life with their 42t replacement sprocket. Designed to fit on your standard 10-speed mountain bike cassette, the sprocket offers the super low range of the 42t cassette without having to make huge changes to your drivetrain.
Thanks to the advent of high-quality non-drop chainrings like Wolf Tooth Components, drivetrain experimentation is at an all-time high (at least for me). While it is possible to go 1×10 with a standard Shimano or SRAM 11×36 cassette, there are definitely times that a wider range would be welcomed – which is why the XX1 cassette offers 10-42t. The OneUp components sprocket won’t get you that 10t, but it will bump up the low range to a tractor-pulling 42t.
Built to use a standard 9/10 speed freehub body, the 7075-T6 sprocket includes 12 shift ramps CNC machined into the surface that are optimized for an 11-36 cassette. Once adapted, the net weight increase for the cassette is 51g and offers a 17% range improvement in the gearing.
Just how do you go about adding a 42t sprocket to your cassette? Well, essentially you are removing the 17t cog and replacing it with the 42t. There is an included spacer that must be positioned differently if you’re running SRAM or Shimano, but the directions make it plenty clear. In the case of a Shimano M771 11-36 cassette, this takes the gearing from 11-13-15-17-19-21-24-28-32-36 to 11-13-15-19-21-24-28-32-36-42.
Will you miss that 17t? It depends on the bike, your gearing, cadence, etc. – but we hope to find out soon. OneUp’s 42t is compatible with most 10-speed medium or long cage derailleurs, as long as they offer enough chainwrap capacity for your selected gearing (largest rear sprocket – smallest rear sprocket) + (largest front chainring – smallest front chain ring). It should go without saying, but depending on your chain length you may need to add a link due to the bigger gear. As for the cassette, OneUp is compatible with the following 10 speed models:
Shimano
- XT (CS-M771-10 11-36)
- XTR (M980 11-36)
Sram
- X5 (PG-1030 11-36)
- X7 (PG-1050 11-36)
- X9 (PG-1070 11-36)
OneUp points out that the Shimano Deore, SLX, and SRAM 1080, 1090, and 1099 cassettes are currently not compatible with the 42t adapter sprocket. Compared to something like the General Lee 25-40T cassette adapter, the OneUp sprocket fits both SRAM and Shimano cassettes with the same part and retains more of the original steel cassette gearing. Like the XX1 cassette, only the largest, 42t cog is aluminum which helps to maintain drivetrain durability. Also, due to the nature of the OneUp sprocket’s design since the lowest cogs rarely are worn out, you can replace the rest of the cassette while keeping the OneUp for future use.
The OneUp 42t sprocket is available in black or green with the MSRP set at $100. The first sprockets are shipping out in January and will ship anywhere in the world for free. Check out OneUp on the web for additional product info and to place your order.
