Adventure Cycling Association

The gravel trend continues to grow, and with it, the choice of bikes. There are a lot of great options out there, and a lot of them are similar. They have similar geometry. They have similar drivetrains. It makes sense — bike companies have figured out what works. So, in an industry where convergent evolution is producing rival bike models that might as well be siblings, what got me interested in Priority’s Gemini Smart. Shift Gravel is that it’s different. As a prominent manufacturer of belt-driven bicycles, Priority was already a bit outside the mainstream. But with the debut of Pinion’s Smart. Shift system, the New York-based company jumped at the chance to push the boundary even further.

If you’re not familiar with the Pinion, it’s a German-engineered and -manufactured internal gearbox with a massive gear range. Basically a mini automotive transmission, its gears are steel and live in an oil bath inside a dust- and waterproof box where you’d usually find the bottom bracket. When paired with a Gates Carbon Belt Drive, the Pinion replaces the finicky chain-and-derailleur drivetrains with something that, aside from an annual oil change, should be nearly maintenance free. If set up correctly, the belt never needs lube, sheds dirt, and should have a lifespan of 10,000 miles, roughly three times that of a chain. The gearbox should last 60,000 miles, though Pinion recommends you send it back for reconditioning after 25,000 to 30,000 miles. So for a little more weight, you can say goodbye to bent derailleurs, broken or dropped chains, missed shifts, skipped gears, and many of the other headaches and hazards of a traditional drivetrain.

Pinion gearboxes aren’t exactly new. The company’s founders developed the idea in 2006 while working at the Porsche (yes, that Porsche) Development Centre and launched the first mass-produced version in 2012. The core idea has seen plenty of updates and revisions since, but dropbar bikes haven’t come kitted with Pinions because earlier transmissions used a grip shift best suited to flat bars. That changed with the introduction of the company’s Smart. Shift electronic shifting system in 2022, which included an option for a dropbar brake shifter from TRP.

That’s a lot of engineering to parse through, but the result is easier to digest: I was blown away.

I started my test of the Gemini on a local route that I usually climb in my granny gear. But the 12-speed version of the Pinion gearbox that comes standard on the Gemini has a giant 600-percent gear range, meaning that I had multiple easy gears from which to choose. (For reference, SRAM’s X-Range 2-by-12 drivetrain maxes out at a 512-percent gear range.) As I ascended steep and punchy dirt roads and blasted down the other side just to climb again, the gearbox let me skip multiple gears at a once without dropping or jamming the chain … because there was no chain. I could even shift while stopped without lifting my rear wheel and cranking the pedals by hand. Instead, after a few clicks, I was simply in the gear I wanted as soon as I started pedaling again. No clacking, no skipping of the chain over the cassette teeth, no fuss.

All of this meant that the Gemini was perfect for Vermont where gaining 1,000 feet every 10 miles is standard for gravel rides, and many of those climbs feel like they go straight up. This bike gave me the gear range I didn’t know I wanted to get up hill after hill.

Combine this with the Gemini’s middle-of-the-road geometry, which falls between road-y and mountain bike-y, and you have a versatile rig good for all kinds of riding, from commuting to off-road adventuring. I tested the aluminum version ($3,499), but the Gemini is also available in titanium ($5,499), which saves a pound. That might be worth it for some. At 26.5 pounds in size medium, the aluminum Gemini is heavier than a lot of other gravel bikes in its price range. But because much of that weight is in the gearbox, which clocks in at around 5 pounds, the extra mass is low on the frame and helps give the bike a stable feel.

The WTB rims and tires are tubeless compatible, but if you want to forego tubes, you’ll need to set the tires up yourself or pay a shop. The narrow-ish 40-millimeter tires were well suited to hard-packed surfaces and less suited for techy gravel or singletrack. But the frame and fork can fit up to 50 millimeters of rubber, so swapping them out could make the Gemini more capable on gnarly terrain, as would adding a dropper post. (The frame has internal routing for a 31.6-millimeter dropper.)

If you’ve used electronic shifters before, the drivetrain will feel similar. If you haven’t, imagine pushing buttons on a remote control. What’s different, however, is that the bike only changes gears when the cranks are vertically aligned. So, if you’re pedaling slowly, it can feel like it takes a second. The TRP levers were ergonomic and comfortable, and the hydraulic TRP brakes they’re paired with performed well on gravel. The shifter needs charging after every hundred or so hours of riding, according to Priority. I charged mine when I got the bike, and I haven’t needed to do so again yet. It took about an hour to top off from completely dead.

The one component I didn’t love was the handlebar. The drops were too short for my taste, and I prefer a bar with a little more flare. The bar tape also needed fixing because the ends weren’t secure. But these were all minor issues and, except for the tape, personal preference.

All told, while it’s not the bike I’d choose for racing, it is a bike I’d choose again and again for touring. Between the no- to low-maintenance and the gear range, I’m sold.

Editor’s note: While we chose to review the Priority Gemini Smart.Shift Gravel bike because it is the prize for Adventure Cycling’s year-long nonprofit member and donation drive, the author’s review was conducted independently, and her opinions are her own.

GENERAL

BEST USES: Gravel, bikepacking, road riding, commuting, touring
PRICE: Aluminum $3,499 (tested); titanium $5,499 (pictured)
WEIGHT: 26.5 lbs (M)
AVAILABLE SIZES: XS, S, M, L , XL
SIZE TESTED: S
CONTACT: prioritybicycles.com

COMPONENTS

FRAME: Butted T6 6061 aluminum or 3Al-2.5V titanium; dropper post compatible
FORK: Carbon with carbon steerer
TIRES: Tubeless-ready WTB Vulpine 700 x 40 mm
DRIVETRAIN: Pinion C1.12i Smart.Shift; Gates 115t CDX belt
WHEELS: Tubeless-ready WTB KOM Team i23
BRAKES & SHIFTERS: TRP Hywire