Mid-cycle updates have improved the A/1, but the frame geometry is still a little too goofy for our liking.

photography by James Huang and Dave Rome

I reviewed the first-generation Vaast A/1 magnesium gravel bike in November 2020, and found a lot to like, but also some areas that needed improvement. Thankfully, the folks at Vaast seemed to be listening, and they took some of those criticisms to heart. This latest version is an update on the original rather than a wholesale redesign, but are the changes enough to really move the needle? Not enough, unfortunately.

I won’t rehash all of the tech details on the Vaast A/1 since it’s not a complete redo (you can read the original review here), but I’ll go over the high points.

Magnesium is certainly one of the most unusual metals being used in bicycle frames these days, but a look at its material properties offers plenty of clues why brands find the stuff enticing. As compared to aluminum, magnesium is lighter and stronger — it’s the lightest structural metal, in fact — it damps vibration better, and on the sustainability front, it’s less resource-intensive to process. The promise has always been that magnesium frames could come even closer to the performance of carbon fiber than aluminum while still retaining a low cost and offering even better long-term durability. 

Vaast is the newest company to take a stab at the idea, and it’s a brand wholly built around magnesium bikes. In fact, Vaast’s parent company, Allite, just happens to be the company that’s making the magnesium tubing — and not only for Vaast, but also for any other company that wants to use it, in cycling or otherwise. 

That said, magnesium has been tried before for bicycle frames with varying degrees of success, and corrosion has historically been a stubbornly persistent problem. However, Allite’s particular magnesium alloys — collectively dubbed “Super Magnesium” — are supposedly just as corrosion-resistant as aluminum, and there are various alloy blends of the stuff to suit different forming operations, such as extruding, machining, forging, and welding.

This A/1 is Vaast’s all-road/gravel model, built with a TIG-welded magnesium frame and offering clearance for 700×42 mm or 650×50 mm tires. The tubing is nominally round at first glance, but a closer look reveals some subtle flaring at the forward ends of the top tube and down tube to provide more front-end strength. The large-diameter chainstays sport rounded-rectangular cross-sections, while the seatstays are more or less straight and round from end to end.

Those stays meet up at machined magnesium dropouts with both fender and rear rack mounts, while at the forward end of the dropped driveside chainstay is a short forged section integrated with the T47 oversized and threaded bottom bracket shell.

Cable routing is internal through the down tube, and the tapered head tube surrounds a full-carbon fork with integrated fender mounts. There are also bottle cage mounts on each leg (which can also be used for hauling lighter-weight gear), and two bottle cage mounts inside the main triangle on the down tube and seat tube. 

Claimed frame weight is 1,300 g for a medium size — not bad at all.

Changes on this latest generation of Vaast A/1 are subtle, but significant.

That dropped driveside chainstay now doesn’t drop down quite as low as it did before, which should prevent the lower chain rub and slap that plagued the first generation. And while the original A/1 was only compatible with single-chainring drivetrains, this updated one works with front derailleurs to provide some more flexibility and versatility. 

What hasn’t changed is Vaast’s impressive value. 

In keeping with the theme of this year’s Field Test, I intentionally requested one of the lower-end builds for this Vaast A/1. Specifically, our A/1 2X GRX 700c is outfitted with a complete Shimano GRX 400 2×10 mechanical groupset, with the exception of a Praxis Alba M24 forged aluminum crankset with 48/32T sub-compact chainrings, and a KMC chain.

The wheels are built with WTB i23 23 mm-wide tubeless-compatible aluminum rims, double-butted stainless steel spokes, and no-name cartridge bearing hubs, all wrapped with 37 mm-wide WTB Riddler tires.

WTB also supplies its popular Silverado saddle, but the rest of the finishing kit is all Vaast-branded stuff, including a basic two-bolt aluminum seatpost, a forged aluminum stem with a four-bolt faceplate, and a flared aluminum drop handlebar wrapped with pleasantly fuzzy tape.

Total weight for our XS-sized sample (XS??? I’ll get to that) is 10.08 kg / 22.22 lb. Retail price is US$1,900 / £2,000 / €2,000 (Australian pricing is TBC).

My previous experience with the A/1 confirmed a lot of the claimed benefits of magnesium. The ride on that bike was exceptionally well damped — almost as if the tires were low — but yet the bike was still quick and snappy under hard pedaling and offered precise handling thanks to the stout front end.

Some of those characteristics carried through on this second-generation sample, but not all of them. 

As before, those oversized and subtly shaped frame tubes make for a stiff frame that’s highly resistant to flex. There’s also plenty of vibration damping evident in the muted feel. However, every tester commented how overly stiff this particular frame felt on bumpy terrain. Vaast doesn’t appear to do size-specific tubing for the A/1, and with the smaller size we tested this time around, there’s essentially zero noticeable give. 

“The ride was stiffer than expected,” said CyclingTips senior tech editor Dave Rome. “I’d heard good things about the smoothness of magnesium, but this frame was just stiff in all directions.”

Without question, much of this excessive stiffness can be attributed to the frame size.

Vaast made a mistake on our shipment and sent an XS instead of the S that was requested, and unfortunately, there wasn’t enough time before Field Test kicked off to get a replacement in hand. But as it turns out, the XS wasn’t as far off as it should have been in terms of overall sizing, and it only further highlighted the bike’s unusual layout.

Size-specific tubing would definitely have helped the smaller A/1’s ride quality, but more appropriate proportions would have helped a lot more. As with the medium-sized Vaast I tested in 2020, this revised XS sample still features a perplexingly long seat tube. At 500 mm, the Vaast seat tube is 34 mm longer than the smallest Specialized Crux, 70 mm longer than a Giant Revolt, and 90 mm longer than a Cannondale Topstone. As such, even though Vaast uses a comparatively skinny 27.2 mm round seatpost here, it doesn’t matter since there’s so little of it sticking out of the frame.

And yet although the seat tube is very long, the head tube is curiously short. At 514 mm, the Vaast’s stack is 16 mm lower than the Crux, 42 mm lower than the Revolt, and 20 mm lower than the Topstone. That’s not exactly the “more upright riding position” the company explicitly touts on the bike’s web page, and yet across the board, those curious proportions are also matched to short reach dimensions. 

Taking all of that in total, it’s as if Vaast’s frame designer was harking back to the olden days of road racing bikes with short and level top tubes, long seat tubes, and short head tubes, instead of looking forward to modern gravel bikes with their lower and more stretched-out layouts.

“It could be argued that a small frame is naturally stiffer, but a lighter rider on this size is going to flex the bike even less than I did,” Dave said.

Dave and I were still able to get our testing down after swapping to longer stems, though, and both of us noted how the amount of exposed seatpost appeared totally normal despite the XS sizing. That said, the extra-small A/1’s geometry was better suited in stock form to our shorter two testers, Velonews senior editor Betsy Welch and pro-racer-on-sabbatical Ellen Noble. But even then, there were comments about an odd-feeling handling geometry up front, seemingly due to the extra-slack 69.5° head tube angle.

“The front end felt heavy and made maneuvering it off-road very cumbersome,” said Ellen.

There was another oddity we just couldn’t put our fingers on. For whatever reason, the Vaast A/1 just felt seriously slow — like, rolling-through-molasses-with-the-brakes-dragging slow. We initially attributed that to the lower-end tire casing construction and thick butyl inner tubes, but even after borrowing wheels from other bikes that felt markedly quicker (and checking all of the other usual suspects like the brake alignment and bearing smoothness), that draggy feeling persisted. 

The draginess was something we unfortunately weren’t able to explain, but something several testers independently logged in their ride notes. On side-by-side rides, whoever was on the Vaast also consistently felt like they were working disproportionately harder to keep up so we know we weren’t imagining things. It’s worth noting that I didn’t feel like the medium-sized A/1 I tested in 2020 was oddly slow, so this one is unfortunately a head-scratcher.

Much of this criticism is especially disappointing given how well Vaast executed a lot of other things about the A/1 frame.

The hydroformed tubing is gracefully shaped, and the TIG welds that join everything together are nice and even. Especially considering Vaast’s minuscule market share, there’s an outsized amount of investment evident in the forged bottom bracket shell with its integrated driveside chainstay section, as well as in the machined-in-house dropouts. And the finish is absolutely gorgeous, with deep and lustrous pearlescent paint that absolutely pops in bright sunlight.

The disc brake mounts were also well aligned and easy to adjust, the seat tube was cleanly reamed, and the whole bike was refreshingly free of creaks and squeaks. The threaded T47 bottom bracket shell? So easy. And the conventional 27.2 mm round seatpost and external clamp? Yes, please.

The only other major letdown was the cable routing. For whatever reason, Vaast continues to insist on single-entry internal routing on the side of the down tube, which is both visually and functionally awkward. The housings and brake hose end up at funky bends and angles, and the chunky rubber plug that helps to seal up the hole just looks amateur and clumsy.

The build kit is solid all around with clearly plenty of attention paid to detail.

The Shimano GRX 400 mechanical groupset may be the least expensive in the GRX family — and the only one of the bunch to use a 10-speed cassette out back — but it shifts just as well. Chain movement is quick, precise, and consistent despite the substitution of a KMC chain, and although Ellen felt the hoods were too big for her hands, the lever ergonomics were otherwise hard to fault with easily accessed controls and a smooth, silky feel to the shift lever action. 

Kudos to Vaast’s product manager(s) for the Praxis Alba crankset, too. While the shift performance isn’t quite on par with what the GRX 400 unit would offer, it’s not far off. It’s also lighter and uses a standard chainring bolt pattern so replacements will be easier to source down the road. Speaking of chainrings, that’s the one downside here: while the GRX crank is offered in a 46/30T combo, the Praxis is a touch bigger at 48/32T, which Ellen felt was a little too tall for the intended purpose.

There were no complaints with the hydraulic disc brakes, however, which delivered superb power and control, together with a light and snappy feel at the lever. The resin pads didn’t squawk too much in wet conditions, either.

As mentioned earlier, all of the finishing kit (aside from the generally agreeable WTB Silverado saddle) is generic Vaast-logoed aluminum stuff. However, whoever’s doing the sourcing here has made some good decisions. The forged aluminum stem is very nicely finished, especially at the four-bolt faceplate, which is where you often see some cost-cutting. The aluminum bar also sports a pleasant compact bend that’s comfortable to hold, it has just the right amount of flare, and it has tight-radius upper bends that don’t needlessly constrict useful width up top. And although the seatpost is nothing special, the two-bolt design at least holds tight and is easy to adjust with readily accessible bolt heads.

The rolling stock is unfortunately more of a mixed bag.

The 23 mm-wide WTB i23 aluminum rims generally have a good reputation and stayed true during our testing, and prior experience has proven they work well tubeless. Although the versatile tread design of the WTB Riddler is one of my personal favorites, the steel beads aren’t tubeless-compatible so you’ll need to spend a fair bit of money on new rubber if you want to ditch the inner tubes.

“I flatted the tires at nearly 40 psi,” Ellen said. “It’s disappointing with today’s industry standards to not be able to easily convert to tubeless when it’s clearly so necessary for a decent ride.”

And while less technically savvy buyers might be excited to see the hubs are built with cartridge bearings, there are no markings on the hubs whatsoever, so good luck finding freehub parts down the road.

The A/1 impresses in a lot of ways, not least of which is the quality of the frame construction and the materials used. Simply put, it’s quite the accomplishment to offer something like this — made of a semi-exotic material like magnesium, no less — and to do just about everything in-house, too. Additional points go to Vaast for the mostly excellent build kit (although the lack of true tubeless compatibility is a major bummer). 

I’m pretty sure I’ve used this analogy before, so you’ll have to excuse me for using it again. 

You often hear that location is the most important when buying a house. While you can always (at least in theory) renovate or remodel, you can’t change where the thing sits. It’s a similar story with bikes and frame geometry: it’s easy to swap parts and make upgrades. But if the frame geometry isn’t right, there’s virtually nothing that can be done to fix it. 

That’s unfortunately the situation with the A/1. Vaast legitimately seems to have all the ingredients for success here, but the geometry is all wrong. Across the size range, the seat tubes are too long, the head tubes are too low, and the top tubes are too short. And making matters worse is the fact that good frame geometry doesn’t cost any extra; you just have to get it right. 

Hey, Vaast, how about we try again with v2.0 instead of v1.2? Because we’d sure love to see what can really be done here. 

More information can be found at www.vaastbikes.com.  

CyclingTips Field Test group bike tests are never paid for by the brands that make those bikes, but they’re still only possible with some outside assistance. CyclingTips would like to thank Assos for their generous support of this year’s Field Test.