Absolute Black Oval Guide
As the name suggests, Absolute Black designed their new chain guide with elliptical chainrings in mind. They go so far as saying it’s, ‘the only chain guide on the market that is designed specifically for oval chainrings.’
Oval rings are all the rage at the moment and it’s true that they don’t always work well with a chain guide. Their variable outer radius means that some guides won’t fully cover the chain at certain points in the pedal stroke. In other cases it can be hard to fully eliminate chain rub when running an oval ring.
That said, we’ve successfully used a number of regular chain guides on oval 1X drivetrains. It can certainly work, it just depends on the guide as well as the individual bike setup.
The Oval Guide is a clean and minimalist design that weighs next to nothing; only 24g for our ISCG 05 guide, and that includes all of the chain line spacers as well as the titanium mounting bolts. In addition to the regular ISCG 05 style, Absolute Black also makes top direct mount and S3 e-type versions, plus a tiny 17.5g ‘mini-guide’ that fits to ISCG 05 bikes with a threaded bottom bracket.
Without reading the instructions, the guide took around five minutes to fit. It may have been a fraction quicker if I’d checked out their online video first. In any case, the process is straightforward. The most involved part was selecting the right combination of chain line spacers. It can be adjusted for chain lines ranging from 47-53mm, so the one guide caters for both regular and boost drivetrains.
It offers enough vertical adjustment to handle oval chainrings from 26 up to 34 teeth or 28 to 36 teeth with round rings. T25 Torx hardware is used throughout, so you only need one tool for mounting and adjustment (you’ll find a T25 on most multi-tools). One word of caution however; the aluminium Torx fitting that secures the nylon guide is relatively shallow and will round out if you get overzealous—only tighten it to 3nm as recommended.
Flip Top Front
Possibly the coolest feature is the ‘front flip’ design. The outer plate of the guide rotates upwards allowing you to remove the cranks or swap chainrings without removing the guide. You simply grab the outer plate and twist—no tools required. At first I was concerned it would flip open when riding but there’s enough friction in the pivoting action that it stays in place.
I ran the guide with both oval and round chainrings, trying it on a few different bikes and it worked as advertised. With the correct setup it was silent and drag-free through the entire gear spread on an 11-speed drivetrain. It also kept the chain in place no matter what I threw at it. While the overall design is a minimalist affair, the sides extend down far enough that they fully encompass the chain at all times, even with the up and down movement of an elliptic chainring.
Chain guides aren’t essential if you’re running a clutch derailleur and a narrow/wide chainring, but it’s still possible to bounce the chain off if you ride hard enough in rough terrain. If you like to charge hard down the trail, a guide like this provides extra insurance against chain loss. And with no drag and only 25g of added weight, the only disincentive is the price, as the Absolute Black Oval Guide retails for just over $100.
SCV Imports (02) 4353 2633
www.scvimports.com.au
