Widespread acceptance of one-by cranksets has created additional opportunities for innovation, and one of those is OneUp's new Switch Chainring System. No surprise if quick-change gearing isn't on your short list of must-have accessories. It's a fresh concept. Most trail riders grew up with fussy front derailleurs and multiple chainrings, while gravity and all-mountain riders wrestled with single-ring cranksets enshrouded by complicated chain guides. Once you got all those bits working correctly, the last thing on your mind was experimenting with different size chainrings.
Until recently, if one wanted taller or lower gearing, the default was a new cassette - an expensive purchase, but much less complicated to install. Even if the thought did occur that it would be great to customize your gearing for a full day of climbing or for a gravity day at the bike park, the negatives far outweighed the positives.
OneUp offers spiders that fit all popular direct-mount cranksets, Switch chainrings (round or oval) interchange with all spider configurations.
OneUp Switch Chainring System
Today, however, single-chainring drivetrains with narrow-wide sprocket profiles have turned that equation up-side down and OneUp Components gets it. An 11 or 12-speed cassette can cost upwards of $500, while chainrings are priced around $40. OneUp engineered a small spider that interlocks with the sprocket. The chainring is secured with four Allen screws, but they only need to be backed off two revolutions to release the sprocket. All the hardware remains in place, and the width of the spider and the design of the chainrings is such that the sprocket can be removed or installed over the crankarm and the pedal. Switching to a different chainring can be done in less than two minutes, using only a four millimeter Allen key. OneUp's Switch Chainring System makes it practical and inexpensive to match your gearing to the task at hand.
The chainring interface unlocks in a clockwise direction.
Carriers (Spiders): All types, $23 USD • Race Face Cinch - Standard, Boost, SuperBoost • SRAM style 3 bolt - Standard, Boost, SuperBoost, BB30 short spindle • Hope - Standard and Boost • E*Thirteen - Standard and Boost • Cannondale - Standard, Ai, FatCAAD
Chainring Sizes: USD • 28T oval and round - $40 • 30T oval and round - $40 • 32T oval and round - $42 • 34T oval and round - $44 • 36T oval and round - $44 (All chainrings fit all carriers)
Beyond the obvious, the Switch Chainring System also helps to future-proof your crankset. Spiders are available to fit popular direct-mount cranksets from Race Face, SRAM, Cannondale, e*thirteen and Hope, and for Boost and standard chain lines. Oval and round chainrings are available in even-tooth increments from 28 to 36. All Switch spiders cost $23 USD, while chainrings range from $40 to $44 USD. OneUp's options ensure that you can update your next bike or crank purchase to accept your selection of chainrings, and also reduces the cost and complexity of replacing worn sprockets.
Rear derailleurs are a limiting factor. Both SRAM and Shimano mid- and long-cage derailleurs have enough wiggle room to absorb chainrings one size larger or smaller (narrow-wide chainrings require two-tooth increments). Depending upon the chain length, when dropping down to a smaller sprocket, it may be necessary to adjust the B-tension screw to fine tune the derailleur cage's tension.
The locking interface rotates into place (front view)...
...And is secured by a standard, reversed chainring bolt (rear view).
Jumping up one size larger usually can be done without any adjustments. So, in most cases, if your chain length is set for a 32-tooth sprocket, you can swap between a 30, 32 and a 34-tooth chainring without adding or subtracting chain links. Want to go huge? Assemble a two or a three-link chain segment and use a second quick-link to adjust the chain length so you can jump back and forth from a 28 to a 36 tooth sprocket with a minimum of additional fussing.
The spider design allows the sprockets to clear the crankarm and pedals for easy removal and installation.
I installed the OneUp Switch Chainring System on a Race Face Next crankset, as well as a SRAM X01 and Eagle XX1 cranksets with no difficulties. I anticipated that I might have issues with the quick-change interlocks either loosening or creaking over time, but neither occurred. OneUp's system is still running silently after nearly three months of unseasonably wet riding for sunny Southern California.
The quick-change feature is as simple as simple gets. With practice, I could switch chainrings in under two minutes. An unexpected plus was that I could install or remove the sprocket with the chain in place out from under a chain guide. OneUp sent me the chainring options that I use most (30, 32, 34 and 36-teeth) so I set the chain lengths of the test bikes for the middle of the three options I planned on using (32t for a 30 x 34 range and 34t for a 32 x 36 range). There was no noticeable difference in shifting while riding the three options with SRAM Eagle, XX1 and Shimano XT rear mechs - and, as long as the chain was not set too long, there was no need to adjust the B-tension screws.
Did I find the option to switch gearing useful? Yes, but it took a few times to get into the habit. Initially, I forgot that I could easily pop a more suitable chainring on the bike until I was midway into a long, technical uphill slog and my legs were screaming. Now, I'll put a 36 on my enduro bike if I am shuttling downhill trails, and if I need to pedal the 30-pound monster to the top, I am not ashamed to drop down to a 32, so I can cruise the climbing trails and be fresh for the downs.
Beyond legs and lungs, however, there is always the extra wear and tear on the expensive drivetrain parts that occurs when the chain is dragging on the sprockets at extreme angles to consider. And, perhaps more important is that most rear suspension designs are tuned to react best when the rider is using the middle ranges of the cassette gears. Adapting your chainring size is a simple tool to move the gears you pedal most often in towards the center of the cassette, where suspension kinematics are optimized and the transmission is more efficient.
I am sure that many riders will question the usefulness of quick-change gearing, but the bottom line is that, until you've tried it, you'll never really know. OneUp's Switch Chainring System is intelligently designed and simple to use. I doubt that many enduro racers would do it, but the possibility to drop down two or four teeth would make it much easier to top those monster liaison stages that seem to be popular on the EWS circuit. An extra chainring weighs almost nothing, and OneUp's clever interlock makes it both possible and practical to switch to your race gearing at the top. (Whether that would be legal is another story.)
For the rest of us, OneUp's Switch Chainring System offers an affordable, do-it-yourself option that, at the very least, should encourage riders to experiment with different gearing or oval chainrings. And, in its best expression, OneUp's system will enable riders to better match their gearing to the terrain and optimize the use of wide-range cassettes.—RC