Introducing the VO Gravel Crankarms & Chainrings: Classic Style Meet Modern Gravel

As we develop bikes with wider and wider tires, we often run into a puzzle that every frame designer faces - the bottom bracket cluster is a battlefield where you’re fighting for every single millimeter of space. That's why we developed the new VO Gravel Crankarms and Chainrings. They solve a multitude of issues including tire clearance, front derailleur position, bottom bracket compatibility, chainstay interactions, and yes....looks.

As tires get more voluminous, chainstays have to push outward to clear all that rubber. Standard road and vintage double cranks quickly run out of room - either the chainring or crankarm hits the stay, the tire rubs the chain, or the front derailleur touches the tire. One workaround is to throw up your hands and spec mountain bike components. But then you are limited to small chainring sizes (often 1x only), very wide Q-factors, and compatibility limitations on drivetrains and that just won't do. Certainly not at VO. This is where "gravel" components shine.

Understanding Chainline: Why Gravel Needs Its Own Standard

Chainline is measured from the centerline of your frame to the center of your chainring setup. As rear hub spacing and tire sizes have expanded over the decades, chainlines have had to move outward to keep the drivetrain running (mostly) straight to the middle of the cassette.

Here is how chainlines stack up across different disciplines and why a dedicated gravel chainline is so critical for modern bikes. Now keep in mind the following are more or less standards. There is some variation depending on bb selection and specific applications.

• Track / Fixed Gear (~42mm): Built around tight 120mm rear hub spacing with minimal tire clearance. The chainring sits as close to the frame centerline as possible for a razor-straight path.

• Road Double (~43.5mm – 45mm): Designed for traditional 130mm or 135mm rear spacing and narrow-ish road tires. On modern wide-stay gravel frames, a road double chainring and crankarm will almost always collide with the drive-side chainstay.

• Road Triple (~45mm – 47.5mm): Traditional touring setups use triples to push the outer rings outward slightly to make room for a small granny ring on the inboard side of the crank. While functional, it requires specific triple front derailleurs and outside of our Triple Crankset, these are harder to find new with nice looks.

• Gravel 1x & 2x (~47.5mm – 50mm) — Where We Are: Optimized for 135mm QR or 142mm thru-axle rear spacing running 40mm to ~2.1" tires. By spacing the rings further out, you gain the clearance required to clear wide stays without throwing off shifting across the cassette. 

• 1x Mountain Bike Non-Boost (~49mm – 50mm): Standard MTB spacing for 135mm/142mm hubs paired with larger trail tires. Often these cranks and associated frames have ring size limitations of around 36t max. You can find larger rings, but you're going into CYOA (choose your own adventure) terrain. There are very limited 2x options here nowadays.

• 1x Mountain Bike Boost (~52mm – 55mm): Designed for very wide 148mm rear thru-axle spacing and even wider, 2.4"+ tires. While it offers massive clearance, running a Boost crank on a gravel frame pushes the Q-factor unnecessarily wide and causes extreme chain angles in your larger cassette cogs. It would be very weird to run this on a gravel bike. If they are around, they aren't long for this world.

These New Cranks

Our new Gravel Cranks land right in that sweet spot: giving you true modern gravel clearance without forcing you into clunky MTB components or proprietary chainring combos. For the driveside crank arm, we opted for a standard 5 bolt spider using a 110 bcd outer and 74 bcd inner chainring mount. These have options a-plenty. So if you don't want to use our rings for whatever reason, you can get other rings without issue. Reading further along, you'll see our current ring options in 1x and 2x. If you want something else, let us know and we can see if we can include them in the future :)

One decision we made was to use a tried and true square taper bottom bracket spindle. It isn't just because we already sell them. It's also because, personally, looking through catalogs of bottom brackets for 2-piece cranks and the insane amount of "standards" including internal, external, asymmetrical vs symmetrical, spindle diameters, and not to mention how the spindle actually attaches to the other crank arm kinda made me angry and frustrated. And if I feel that way, then you probably would to. Additionally, with a square taper, you can get a slightly wider or narrower spindle or use simple spacers so you can dial in your chainring and crankarm position to the bike. 

Hey, Looks Matter, Too

And let’s be honest; contemporary gravel cranksets have gotten a bit... intense. Between aggressive angular lines, massive graphics, and proprietary interface standards that seem to change every season, finding a clean, classic-looking crankset for a modern gravel or touring build has felt like an uphill battle.

Designed for riders who appreciate a timeless three-piece square taper look without giving up modern chainline geometry, these arms pair a smooth, polished finish with minimal, precision-engraved VO logos. They let your frame build do the talking, whether you're building up a custom dirt-tourer, restoring a vintage rig with modern gearing, or spec'ing an all-day gravel machine.

Your Drivetrain, Your Way (À La Carte)

Rather than forcing you into pre-packaged chainring combos, we’re offering these cranks and rings à la carte. You choose the arms (black/silver, 160mm-175mm), pick your exact ring configuration (outer, inner, or 1x), grab the matching hardware, and pair them with your favorite 118mm bottom bracket (yielding a proper gravel chainline of 50mm and a comfortable 176mm Q-factor). Or you can grab individual pieces and build your own thing!

Whether you want a wide-range double for mountain passes or a streamlined 1x setup, you can build it exactly how you ride:

• For 2x Range Seekers: Pair our 110bcd Outer Chainrings (40t to 46t) with our 74bcd Inner Chainrings (24t to 30t) to create true sub-compact gearing. Up front, the outer rings feature ramped and pinned shift profiles for crisp under-load front shifting, while the inner rings give you the low-torque bail-out gears you actually need when grinding up steep, loose grade with gear. We suggest sticking with a 16t ring difference - that's for optimal shifting.

• For 1x Simplicity: Mount our 110bcd Narrow-Wide Chainrings (38t to 44t) directly to the outer position using the outer hardware. The alternating tooth profile locks onto your chain to keep everything secure through rough washboards and doubletrack chatter without needing a chain guide.

• Don't forget the hardware!

We plan on using these for most of our builds going forward including Chessie, Polyvalent, Low Kicker, and even upcoming Neutrino 2.0!