Vaast A/1 gravel bike review: Magnesium makes a comeback

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Vaast is a new American brand built around Allite’s new “Super Magnesium” tubing. Claimed to be stiffer, lighter, more sustainable, and smoother-riding than aluminum — and at similar cost — Vaast is hoping to succeed where Pinarello, Kirk, and others have failed in the past. The A/1 is the brand’s versatile gravel model, and there’s indeed something special to how this thing feels. However, there are also a bunch of places where the company’s relative inexperience shines through, too.

Story Highlights

  • What it is: The rebirth of magnesium, TIG-welded into a modern gravel bike frame.
  • Frame features: Allite AE81 Super Magnesium tubing, TIG-welded construction, machined chainstay yoke, clearance for 700×42 mm or 650×50 mm tires, internal cable routing.
  • Weight: 1,200g (claimed, medium frame only, unpainted); 8.96 kg (19.75 lb), as tested, medium size, without pedals.
  • Price: US$2,499 / AU$TBC / £TBC / €2,800
  • Highs: Ultra-damped ride quality, very good value, smart spec, gorgeous paint.
  • Lows:Quirky frame geometry, chain rub on chainstay yoke, goofy cable routing, awkward stock lever position.

The power of fairy dust

Bicycle brands have long been drawn to the allure of magnesium, and as far as its material properties go, there are good reasons for that.

Although less stiff than aluminum, it’s also proportionally less dense, supposedly about 20% stronger, and does a much better job of damping vibration. It also requires about half as much energy to extract and manufacture, it’s kinder to cutting tools, and it’s easier to recycle, too.

As a result, the promise has always been that magnesium bicycle frames could deliver weight and performance approaching that of carbon fiber, but at a cost closer to that of aluminum, all while being as durable — perhaps even more so, at least theoretically — than titanium and steel frames.

The tube shaping on the Vaast A/1 is pretty minimal at the moment (such as how the down tube is flared at the head tube for extra strength).

There have been a variety of attempts at bringing magnesium to the forefront of bicycle technology over the years — Kirk Precision, Pinarello, Paketa, Zinn, Easton, Mrazek, to name a few — and while cast magnesium is currently the material of choice for lower legs of most suspension forks, its use elsewhere has found very limited success.

Industrial metallurgy firm Allite is hoping magnesium can finally find the widespread success it deserves, thanks to a new alloy that the company has dubbed (naturally) “Super Magnesium“. Super Magnesium actually comprises four different magnesium alloy variants optimized for different manufacturing methods, but they all share a few common claimed characteristics, such as a more refined grain structure that is said to increase tensile and fatigue strength relative to older magnesium formulations, a lower-than-usual concentration of impurities to minimize the chance of undesired chemical reactions when the alloys are being formed, and a susceptibility to corrosion that isn’t any worse than good aluminums.

Super Magnesium manufacturer Allite says the material is less resource-intensive to produce – and easier (and cheaper) to recycle – than aluminum, titanium, steel, or titanium.

As further protection, Allite’s Super Magnesium is also given a plasma electrolytic oxidation surface treatment (similar to Mavic Exalith, Campagnolo Mille, Keronite, and others) that imparts a durable ceramic-like coating inside and out to effectively seal the stuff off from the elements.

Creating Super Magnesium is one thing, but getting bicycle brands to adopt it is another.

Setting your own trend

Perhaps predicting the industry’s reluctance to jump back on to the magnesium bandwagon, Allite — or rather the parent company that owns Allite — simply created a new brand wholly built around the new alloy.

And thus, Vaast was introduced to the world at the 2019 Eurobike show.

Vaast went for a very straightforward profile on its debut A/1 frame.

Vaast’s current lineup is fairly limited, comprising a single hardtail 29er mountain bike, a youth mountain bike with 24-inch wheels, a flat-bar urban/commuter bike, and the gravel/all-road Model A/1 you see here.

Vaast bills the A/1 as a sort of do-it-all drop-bar machine that is “pragmatically designed for gravel, dirt, pavement, mud, and all other types of adventure ‘roads’.”  Aside from the innovative magnesium tubing, the A/1’s standout feature is its unusual driveside chainstay. While the rear two-thirds of the chainstay uses a conventional tubular construction, the forward section is a machined yoke that extends down toward the ground before being welded to the rest of the chainstay, thus mimicking the dropped arrangement currently favored by a growing collection of carbon gravel bike brands without having to resort to radical shaping that might otherwise weaken the tube.

Vaast inserts a section of forged-and-machined magnesium into the otherwise-tubular driveside chainstay as a way to mimic the dropped designs more commonly seen in carbon fiber frames.

Clearance is pretty impressive for a metal frame with 425 mm-long chainstays, with Allite saying the A/1 can accept a 700×42 mm or 650×50 mm tire. Despite the round seat tube, Allite says the A/1 is purpose-built for single-ring drivetrains, with the yoke offering clearance for narrow-wide chainrings up to 44 teeth.

More machining can be found at the made-in-house rear dropouts, but otherwise, the rest of the TIG-welded frame is pretty straightforward with fairly minimal shaping that includes a small down tube flare up at the head tube to boost front-end strength, a modestly ovalized and curved top tube, and a nice S-bend curve in the chainstays to add some heel clearance. Down below, Vaast has taken a forward-looking approach with a T47 threaded bottom bracket shell, using the slightly narrower 85.5 mm-wide format that Trek introduced last year to provide a bit more flange thickness and better tool purchase than how the system was initially proposed.

The non-driveside dropout is a piece of industrial art.

For a bit of extra versatility, Vaast includes front and rear fender mounts as well as rear rack mounts, plus room for up to four water bottles — two inside the main triangle, and one on each side of the all-carbon fork. There’s no bottle mount under the down tube, though, nor a feed bag mount up on the top tube, both of which seem like odd omissions given the target market.

Claimed weight for a medium frame is an impressive 1,200 grams, without paint or hardware, putting it within spitting distance of midrange carbon fiber gravel frames, and a decent amount lighter than equivalent aluminum ones.

The magnesium frame is complemented by a full-carbon fork.

Vaast offers the A/1 with a SRAM Rival 1 build kit in both 700c and 650b wheel sizes, and a Shimano GRX 600/800 mix in 700c only, all with Praxis Zayante Carbon cranksets and Stan’s NoTubes tubeless aluminum wheels wrapped with Maxxis Rambler tires.

Actual weight for my medium A/1 with the 700c Shimano build is 8.96 kg (19.75 lb) without pedals or accessories, set up tubeless.

Retail price is US$2,499 / AU$TBC / £TBC / €2,799, which is quite good all things considered.

Magical metal

This was my first time riding a magnesium bike, and while I honestly didn’t really know what to expect, I wasn’t thinking there’d be any massively obviously differences in ride quality, either.

I was wrong.

Tubing supplier Allite is promising more elaborate forming in the years ahead, so while the Vaast A/1’s frame looks a bit sedate right now, that could change moving forward, meaning the performance of these bikes should only continue to get better.

Allite claims that Super Magnesium damps vibration “20 times better than aluminum”, and although my butt can’t verify the accuracy of that figure, there’s absolutely something to that claim. There’s a strange quietness and smoothness to how the Vaast A/1 rolls across coarse tarmac and rougher dirt roads, sort of like how a luxury car more thoroughly isolates you from the buzziness of ground texture.

I don’t liken it to reducing your tire pressure, however, as that often comes with more bounciness and a generally more vague sense of what the contact patches are doing. Instead, it’s almost what I’d imagine an out-of-body experience would be like where I’m watching myself ride from above. It’s very weird, and very unusual, but also very comforting (in quite the literal sense).

The generic external aluminum seatpost binder clamp looks a little boring, but you know what? It works a lot better than a lot of those fancy integrated setups that are currently en vogue.

Vaast has also done a good job on the A/1 of tempering magnesium’s more flexible nature relative to aluminum. Although there isn’t much in the way of elaborate shaping on any of the frame tubes, the down tube and top tube are nevertheless quite big, and notably a bit larger in diameter relative to what you find in most aluminum bikes. The A/1 feels pleasantly responsive in terms of bottom bracket stiffness, but what’s more impressive is how solid it feels up front. Even in more demanding situations, the steering column feels firmly connected to the rest of the bike, with nary a hint of twist when slamming the front end into a grippy corner or wrenching the bars side to side in a sprint or steep climb.

As for the steering itself, Vaast has taken a pretty safe route with a middle-of-the-road geometry that feels neither overly stable nor nervous and twitchy. It may not be especially distinctive in this growing sea of gravel bike geometry philosophies, but it isn’t likely to offend anyone, either.

Some other aspects of the geometry are more polarizing, however.

Whereas more brands seem to be adopting a longer-lower-and-slacker approach to new gravel bikes — taking a page from modern mountain bikes — the A/1’s numbers feel like a bit of a throwback. The reach dimension is rather short for any given size, the seat tubes are quite long (and very laid back at 72.5° across the board), and the 68 mm bottom bracket drop is a couple of millimeters higher than what you find in many dedicated road racing machines.

“We wanted to create a timeless, elegant silhouette for our A/1, and felt that the relatively tall seat tubes allow us to create that modern, contemporary look and feel,” explained Vaast marketing manager Joey Burke. “The longer tube allows us to utilize the natural energy absorbent characteristic of magnesium. We are able to absorb more energy and create a more compliant ride while also absorbing the stress the structure is exposed to during off-road riding. The smaller the frame structure, the shorter our butting transitions and potentially higher stress riser.

“The reach numbers were designed to accommodate all-day comfort for the ‘sport biking’ consumer who’s not new to cycling, but relatively new to all-road riding, and we have had very strong positive feedback from the market on our geometry.”

The classic frame proportions look nice, but they also don’t serve the A/1’s core mission as well as a more progressive layout.

There may very well be something to Vaast’s decision to use longer seat tubes so as to maximize the damping effect of Allite’s neat AE81 magnesium alloy. However, damping on a micro scale is not the same as flex on a macro one, and while the A/1 is exceptionally (and almost disconcertingly) buzz-free, those oversized tubes are still about as jarring as you’d think they’d be on anything more than smaller rocks and roots.

As for the 68 mm bottom bracket drop, I’m sorry, Vaast, but I’m not quite buying it. Sure, that figure would be pretty normal for a dedicated road racing frame, but even if the A/1 is meant to serve double-duty as both a gravel rig and tarmac speed machine, that’s not how it’s being outfitted.

I’m undecided on whether I like the geometric orange color accents on this frame. It certainly adds some visual interest, though.

I’d argue that the riding position is a bit weird, too. In particular, that 72.5° seat tube angle is unusually slack, and riders that prefer more of a forward position might have some trouble getting their setback where they’d like it to be. Even then, though, you’re greeted at the other end with that shorter reach dimension. As a result, riders on the fence with sizing may be forced to choose between the fore-aft length that they want, and getting more seatpost extension for a smoother ride.

I can understand Vaast’s desire for a “classic” silhouette, but there’s a lot of room in between this sort of old-school road geometry and an ultra-modern MTB-inspired layout for something that would still yield a more traditional appearance without overly compromising the fit and handling as compared to more capable gravel machines.

The challenges of being a newcomer

As impressive as the A/1 is in a lot of ways, Vaast’s newcomer status reveals itself in others.

I love the way the A/1’s machined chainstay yoke boosts tire and drivetrain clearance without resorting to overly squished tubing, and I personally like the high-tech look it imparts, too. However, Vaast goofed on the geometry of the thing as the lower edge hangs so close to the lower span of the chain that it gets regularly beat up on anything other than smooth asphalt. The incessant rattling is not only annoying from a noise perspective, but it also doesn’t take long at all for the chain to gnaw all the way through the paint.

The lower edge of the machined yoke sits far too close to the lower span of the chain. Vaast claims the tubing plasma electrolytic oxidation surface treatment can withstand this sort of abuse, and while that may be true, this sort of contact shouldn’t happen in the first place.

To be clear, I didn’t notice any corrosion issues during my test period, although it’s worth reminding readers that we don’t get a whole lot of moisture here in Colorado, either. According to Vaast, this is a known issue that is being rectified in a running change, and the company will make available to current owners “adhesive protectors” to prevent undue wear. Either way, corrosion supposedly shouldn’t be an issue regardless.

“The PEO coating is permeated into the material and is very difficult to penetrate through,” Burke said. “If it does happen, the Super Magnesium itself is expected to only lightly oxidize due to the high-purity grade and rare earth element additions that prevent corrosion and oxidation.”

Vaast’s internal routing setup leaves a lot to be desired, too.

Vaast says it made a conscious decision to feature the cable entry point more prominently on the down tube. That seems like an odd decision, particularly given that this grommet looks rather big and clunky. The right-side entry point adds an unnecessary bend, too.

Cables enter the frame on the driveside of the down tube, and then exit just ahead of the bottom bracket shell. The rear brake hose is zip-tied to the non-driveside chainstay from there, while the rear derailleur line tucks back into the driveside chainstay, eventually making its final appearance in front of the rear dropout.

In principle, this shouldn’t be a problem. However, the entry point on the down tube introduces an extra bend in the derailleur housing, and the exit point at the underside of the driveside chainstay introduces another one. As a result, there’s more friction in the line than there should be, as what is normally a light and silky-smooth action at the shift lever ends up feeling a little muddied and vague as compared to what I normally see out of Shimano GRX. The front brake hose also has a tendency to rub on the head tube, which quickly mars the paint unless you’re careful to apply some clear vinyl there.

Functional issues aside, the rubber cable entry grommet on the down tube also looks awkwardly big and clumsy to my eye, and it’s never reassuring to find a zip-tie holding cables together underneath the bottom bracket.

Spec notes

For the most part, Vaast’s product manager has done a good job outfitting the A/1, especially at this price.

Aside from the cable friction issue already mentioned, the Shimano GRX 600/800 groupset works as well as we’ve come to expect from this 105/Ultegra gravel analogue. Shifts are reliably smooth and precise, there’s decent range from the 11-42T cassette and 40-tooth chainring, and the brakes offer ample power and good control. The inclusion of Praxis’s excellent Zayante carbon fiber crankset is a nice touch, too.

The upscale Praxis carbon crank is a pleasant surprise given the bike’s comparatively modest price.

I’d like to see Shimano truly lock out the left-hand lever for 1x applications (the brake lever still wiggles a little bit), but otherwise, I don’t really have any complaints with the drivetrain or brakes.

Likewise, the 700×38 mm Maxxis Rambler tires are a safe and reliable choice. They’re not necessarily the best in any particular performance category, but they roll well enough, grip predictably in a wide range of conditions, and are tough enough to hold up in most usage scenarios. They also readily seal up and hold pressure nicely.

There’s a reason why Maxxis Rambler gravel tires are so popular. They may not be the absolute best in any particular area, but they’re superb all-rounders that work well in a wide range of conditions.

The Stan’s Grail S1 aluminum wheels to which they’re mounted are proper workhorse items as well, requiring no maintenance or truing during my time with them, and holding up surprisingly well to a handful of ugly rock hits. However, they’re hardly lightweight at just over 1,900 grams (claimed), and the 20.3 mm internal width is narrower than I’d like to see.

The WTB Silverado saddle, generic Vaast house-brand carbon fiber two-bolt seatpost, and Vaast forged aluminum stem all get the job done just fine — no complaints there — but the handlebar setup needs some work. The bend itself is OK, but Vaast mounts the levers awkwardly far down on the bend. If you rotate the bars up to get a flatter hood position (which is what most people prefer), the handlebar reach gets uncomfortably long, and the drops end up at a weird angle.

The shape of the handlebar itself isn’t bad, but the way Vaast mounted the levers from the factory makes for an awkwardly long reach. I ended up rotating the bars down about 20°, and sliding the levers up about a centimeter for a much more agreeable setup.

This is hardly a deal breaker, but it’s annoying nonetheless to have to untape the bars, reposition the levers, re-angle the bars, and then tape everything back up again. For seasoned home mechanics, it’ll be a 15-minute job. But for the less mechanically astute, it’s a goofy setup that’ll more than likely just stay that way for the duration, sullying what is otherwise a pretty good bike.

A promising start

I love that this bike exists, if only for the prospect that the promise of magnesium might finally might be realized after so many false starts. Assuming Allite has truly put magnesium’s old troubles to bed (poor reliability and corrosion resistance), what we’re looking at here is the very real possibility of bikes that are lighter and ride better than aluminum, but are also substantially less expensive (and with fewer ecological drawbacks) than carbon fiber.

For a new brand, Vaast has done a lot of things right.

I wish I could say that I loved the actual bike as well, but I’m not quite there. I do like it overall, and there’s clearly heaps of potential, but it still feels a little too unfinished to me: the chain rub on the chainstay, the clumsy cable routing, the somewhat awkward geometry. Burke says the A/1 was developed as a “hybrid between road and gravel,” which may partially explain some of the unusual geometry decisions. However, in trying to split the difference and be everything to every rider, Vaast has just muddied the waters in my view, and compromised the bike’s performance in either situation as a result. The A/1 isn’t a bad bike by any means, but it isn’t as good as it could have been, either.

What I am absolutely very excited about, however, is where Vaast and Allite take Super Magnesium from here. This stuff is genuinely different, and given how far aluminum has come in recent areas with more advanced alloy development and shaping methods, I can only imagine what might come out in the years to come.

Sign me up for v2.0, please.

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