Even with the best of the best narrow wide chainring, when the trail gets rough, using some sort of chain guide gives you that extra security blanket for keeping your chain on the chainring. OneUp Components is a company that came on to the scene with their larger tooth sprockets, allowing you to increase the range of your rear cassette. Now OneUp is most notably known for their EDC multi tool that conveniently fits inside the steerer tube of your bike. In this review, let's take a look at the OneUp Chain guide Max Morgan is running on his trail bike!
The OneUp bottom bracket chain guide uses the same one tool adjustment seen on the ISCG05 chain guide. Using a 4mm hex key, the OneUp guide can be adjusted to fit either round or oval chainrings from 26 tooth to 36 tooth. All of the OneUp chain guides come with two top guide pieces, one green and one black. In the photo below, you will see the bottom bracket mounted chain guide side by side with the ISCG05 mounted guide.
I mounted the OneUp bottom bracket style chain guide on my Santa Cruz Blur trail bike. This bike is a cross country/lightweight trail bike that absolutely rips! Similar to Yeti's new SB100, the Santa Cruz Blur rides more aggressive than what you might expect from a 100mm rear wheel travel XC bike. I certainly have my on take on what a lightweight trail bike should be and that's why I have TRP Quadiem G-Spec four piston downhill brakes, a Fox 34 Step Cast fork with 120mm travel, and 780mm wide Deity Skyline handlebars on my Blur.
This OneUp chainguide is the bottom bracket mounted design, meaning it is sandwiched between the frame and the bottom bracket. The Blur uses a threaded bottom bracket, making it easy to keep the OneUp chain guide nice and secure. My Santa Cruz Blur is built up with a Sram XO1 Eagle DUB Crankset and Sram's DUB English Threaded Bottom Bracket.
When it came time to install the chain guide, I decided to install the XO1 Eagle DUB bottom bracket and crankset first without the chain guide. I wanted to make sure I got the spacing, fitment, and chain line all set to go before throwing the bottom bracket mounted chain guide in the picture. If you aren't familiar with Sram's DUB threaded bottom bracket, it features conventional bottom bracket spacers that get sandwiched between the bottom bracket cup and the frame. All of the DUB bottom brackets also feature an assortment of spacers that can be popped on and off the outside of the bottom bracket bearings so that the crank spindle and chain line is spaced properly.
The Santa Cruz Blur uses a 73mm bottom bracket shell seen most commonly on current trail bikes. Because this particular threaded bottom bracket can be fitted to suit both 68mm or 73mm shells, the 73mm setup calls for no spacers on either the inside or the outside of the bottom bracket cup on the left side (non drive side). The drive side calls for no spacers on the inside and a 4.5mm spacer on the outside of the bottom bracket cup. The OneUp Components bottom bracket mounted chain guide is roughly 2.5mm thick where the guide gets sandwiched between the bearing cups. What I ended up doing was replacing the 4.5mm drive side outside spacer with a 2mm spacer after pinching the chain guide between the bearing cup and the frame. This was you end up with the exact same chain line and crank spindle fitment as before. This wasn't necessarily difficult but if you aren't familiar with Sram's latest DUB system, you might end up with a less efficient chain line or the incorrect retention on the crank spindle.
Once the back plate was mounted, it was time to install the crankset for the final time and then space out the top guide piece to be perfectly centered over the chain ring. At first, I thought the plastic spacers used to align the top guide seemed a little cheap, but it makes it much easier to align the guide than any other design I have seen. On this particular setup, I am using 4 of the plastic spacers provided behind the top guide piece paired with the Sram XO1 Eagle DUB cranks. The chain guide comes with multiple length bolts so if you don't need very many spacers, you can just use the shorter of the two bolts.
Once the chain guide was mounted up and the chain run through the drivetrain, it was nice and easy to see that the OneUp minimalistic design would be right in the correct place to keep the chain on the chainring without any clearance or rubbing issues. It was just time to get out on the trail.
The OneUp Components chain guide is a great option for those riders looking for a small and minimalistic chain device. I haven't had a single problem out on the trail with the chain guide. It does its job, keeps the chain on the chainring, it's easy to adjust, it doesn't make any noise, and it's very lightweight. For those who want to increase the lifespan of both your chain and chainring, running a small chain guide like this is a great option. Having the bottom bracket mounted chain guide available from OneUp was a huge help because the Santa Cruz Blur doesn't have any ISCG05 tabs. With the bottom bracket style guide specifically, just make sure you get the correct chain line and crankset fitment when installing the guide. After that, you will be all set!
Max Morgan is 26 years old, and lives in Brevard, North Carolina. Max grew up in Atlanta, Georgia and started racing downhill at the age of 15. He has now been racing professionally for the last 8 years, competing in the UCI World Cup series and U.S. Pro GRT series. Check out Max's rider spotlight here!
Max Racing the World Championships in Lenzerheide, Switzerland