Building on the success of their 42T, OneUp Components decided to add a 40T sprocket to their line. The 40T version has been specifically designed to run with Zee FR and Saint derailleurs. It will work with Zee FR and Saint with the mode converter in Freeride mode, on most bikes, excluding full suspension bikes with more than 25mm of chain growth. Bikes with high chain growth running Zee FR/Saint do not have enough chain capacity to allow for full rear travel when in the 40T.


The new 40T has all of the features as the 42T. It’s compatible with most Sram and Shimano 10X rear derailleurs, no need to be limited to just one drivetrain company. It’s machined from 7075-T6, weighs in at 70g and has 8 upshift points and costs $90 including shipping.

OneUp Components don’t recommend their 42T be used with Zee FR/Saint. But for all other riders not running these they still recommend the 42T to maximize your usable gear range.

The only customer complaint they had with the 42T sprocket is that they can’t make them fast enough!


With this in mind OneUp will have stock of the new 40T in all their warehouses (USA, UK and Canada) on or before Mar 17th. Shipping is free worldwide and there are no taxes or duties for shipping anywhere in the US and EU.

They can now also recommend that their 40/42T sprockets can be used with both SLX HG81 and 1080 cassettes. Check out OneUps updated compatibility page for full details.

Did you enjoy this article? If so, we would be stoked if you decide to support us with a monthly contribution. By becoming a supporter of ENDURO, you will help secure a sustainable future for high-quality mountain bike journalism. Click here to learn more.