Viathon G.1 GRX 600 gravel bike review: Carbon at alloy pricing

by Dave Rome


Does spending more get you a faster gravel race bike? That’s exactly what we sought to answer with the high-value Viathon G.1, a carbon gravel bike that’s backed by the biggest of big retailers – Walmart.

Walmart’s immense buying power and pre-existing online sales channel means that for just US$2,298 (shipped, within the United States), this new brand can offer a full-carbon gravel bike equipped with quality components, including a Shimano GRX 600 groupset, Mercury G3C tubeless wheels, and Zipp Service Course cockpit components.

At least on paper, the value for money is unquestionable, but a great bike is always more than a sum of the parts bolted to it. So how does this budget-friendly racer ride? Pretty, pretty, good …

Economies of scales, and low mass on other scales

Story Highlights

  • What: A consumer-direct full carbon gravel racer with impressive value.
  • Features: Insane price, proven geometry, 1x or 2x gearing, threaded bottom bracket, 27.2 mm seatpost, more generous tyre clearance than quoted.
  • Weight: 1,010 g (54 cm painted frame, quoted), 380 g (painted fork); 8.9 kg complete bike, with control Continental tyres, without pedals.
  • Price: US$2,298, not available in other markets.
  • Highs: Price, well-rounded handling, race-ready, weight, all big-name components.
  • Lows: Stiff ride, assembly issues, gear cables, limited warranty, no small sizes.

There are few retailers in the world with the buying power and sway that Walmart holds. And that buying power is often used to competitive advantage: Walmart commonly cuts out the middlemen, and then out-prices and out-supplies its competitors across many industries.

And while Walmart’s involvement with the cycling world has traditionally been one of mass-market and low-cost bikes bought in-store, Viathon’s entry signals a new age. It’s a company that gains a pricing advantage through Walmart’s huge buying power, and leverages an existing online sales channel to get the bikes to customers while they wait at home. You can bet that when the product managers behind Viathon called manufacturers and name-dropped Walmart, the pencil was sharpened to a dangerously pokey point.

The bike reviewed here, the new G.1 GRX 600, provides a perfect example of those economies of scale. It’s a bike that uses the exact same full-carbon frame as the more expensive Viathon G.1s in the range – there’s no tweak to the carbon lay-up, or cheapening of the fork for the various price points. Viathon furthers those purchasing efficiencies by only producing the frame in a somewhat limited range of five sizes, and in many cases, even the rather simple two-tone paint is unchanged between the models.

The result is a bike covered in proven, quality, big-name components at a price that’s approximately a third less than its more established competition, and really, not much more expensive than a bare frame.

That frame (which is also sold separately at US$1,498) is no open-mould cookie-cutter thing either. It’s a design unique to Viathon that was designed with help from the well-regarded engineers at Kevin Quan Designers. Viathon’s product manager, Zach Spinhirne-Martin, openly admits to taking close inspiration from a race-inspired bike like the Santa Cruz Stigmata. “I loved how this bike rides,” said Spinhirne-Martin about the previous generation Stigmata. “I only wished it had a bit more tire clearance, [and more] bottle and rack capability.”

Viathon G.1 GRX gravel bike
The G.1 doesn’t step too far away from proven recipes.

And that really summarises the G.1 quite nicely. It’s a bike that in so many ways aligns closely to what the premium Santa Cruz Stigmata is, however, the Viathon adds a little more versatility through additional mounting options. The Viathon adds mounts at the fork, mounts for a rear rack, and space for an additional bottle cage beneath the down tube. However, like the Stigmata, it too lacks Bento bag mounts on the top tube.

That tyre clearance is far, far more generous than the 700 x 40 mm (or 650B x 53 mm) wide numbers that Viathon claim. And really, we suspect a 700 x 45 mm will squeeze in if you’re less fussed about mud clearance. And yep, the frame can be setup with either 1x or 2x gearing.

The frame features are exactly what you’d expect of a modern frame. There’s the usual tapered steerer fork, 12 mm thru-axles, flat mount brake mounts, internal cable routing (using full-length cable housing), and asymmetrical chainstays to increase tyre clearance.

A threaded bottom bracket is only a “feature” as the industry made such a mess of pressfit systems. Hard to argue with trusty threads.

However, there’s also an element of simplicity we quite like. The round seatpost is held by a regular old banded seat clamp. And winner winner: there’s a threaded bottom bracket shell. This latter element is certainly somewhat surprising when you consider Viathon’ R.1 road frame uses a PF30 shell, and that the use of a threaded shell arguably inhibits the available width for tyre clearance. Either way, it’s there as an intended feature.

“I also wanted all of my bikes to perform when pushed hard,” said Spinhirne-Martin of the frame’s stiffness. “I like my bikes to jump when I stand up and crank down on the pedals. I can always add larger volume tires and reduce the pressure for additional comfort when riding gravel or chip-seal, but a wet noodle frame is just painful when you’re dying climbing for hours in the mountains.”

And while it’s far from a silky-smooth ride (I’ll come back to this), frame compliance was a design factor. The seatstays are thin and dropped, and a 27.2 mm seatpost was supposedly picked for comfort reasons, too.

Viathon states that a 54 cm painted frame tips the scales at 1 kg, with the matching fork an equally respectable 380 g. The result is an 8.9 kg complete bike that simply needs some pedals before it’s ready to have a race number attached.

Fast handling and a ride on the stiff side

So how does this high-value racer ride? Well, it’s a lot like the Santa Cruz Stigmata it was modelled after, just not quite as refined.

Mimicking the Stigmata, the G.1 sits more toward the road end of the gravel spectrum with angles which are closer to that of an endurance road bike than a hardtail mountain bike of a decade past. A 54 cm Stigmata offers a 71.5-degree head angle, 74-degree seat tube angle and trail figure of 66 mm (measured with 700 x 40 mm tyres). The Viathon G.1? The same, except a 2 mm shorter offset fork (50 vs 48 mm) results in an ever-so-slightly-slower 68 mm trail figure.

The G.1 geometry chart reveals some extremely familiar numbers.

Other numbers are an almost exact copy, too. Both the Stigmata and the G.1 feature 425 mm chainstays, while the reach and stack figures are also closely aligned. All these numbers are pretty well proven, and create a bike that walks the tightrope between controlled and quick. Not surprisingly, it’s something we got along with well on the Santa Cruz.

They’re numbers that are ideal for tackling a variety of terrain and doing it all efficiently, and overall, the G.1 behaves like it wants to be the only drop-bar bike in your garage. Those reach figures put you into an efficient road-like position, and just like the Stigmata, it’s all sensible, non-offensive, and somewhat plain in approach. Ain’t nothing wrong with that!

Of course, this all depends on your height, and those five available frame sizes only start at 52 cm. This is pretty similar to the BMC URS, and realistically those under 5’ 6” (170 cm) are likely out of luck here.

Where the Viathon differs from the Stigmata is in its bottom bracket height, with the G.1 sitting some 3 mm higher in the air. This doesn’t sound like much, and in reality it isn’t, but it’s just enough to make the G.1 feel a little more jittery in how it tips into corners, while the Stigmata felt that little more planted – something the ride quality certainly factors into, too.

As is so common with gravel bikes fitted with decently big-volume rubber, there was a small amount of toe overlap present on our 54 cm sample. It’s certainly not severe, and despite riding the G.1 in some rocky, tight, and twisty terrain, it rarely presented itself as an issue.

The G.1 features thin and dropped seatstays, however, they didn’t do as much as expected.

Speaking of rocks, the Viathon’s ride quality is certainly on the stiffer end of things, and those thin seatstays weren’t able to tame as much as the Salsa Warbird or even the Stigmata. Sure, it’s no Evil Chamois Hagar, and it’s perhaps even a tad smoother than the Cervelo Aspero, but only just, and certainly not through the front end. Thankfully, like so many of the gravel bikes we tested in Sedona, there is scope to add more seated comfort through a more flexible 27.2 mm seatpost.

The flipside of that is a frame that pounces forward when you ask it to do so. The head tube feels firmly connected to the bottom bracket, and that to the rear axle. It’s what you want in a more race-focussed gravel bike, and in this sense, it gives up very little compared to the likes of the higher-priced Stigmata or Aspero.

Customisable parts spec

Let’s be honest. The spec matters a whole lot on a bike like this, and really, it’s a significant part of Viathon’s value proposition. As mentioned, this is the lowest-cost complete bike in Viathon’s G.1 range, but that doesn’t mean the parts are low-cost.

There’s a complete Shimano GRX 600 2×11 group on this bike, right down to the Ultegra-level Center Lock brake rotors and Shimano threaded bottom bracket. Viathon opted for a low-geared 46-30T chainring matched with a 11-34T cassette. Personally, given the sporty nature of this ride, I’d have preferred to see the larger 48-31T chainring combo used.

The provided gearing is perfectly low for off-road and touring use, while racers may want something a little taller for when on the road. Also note the use of a band clamp front derailleur which will offer a clean looking 1x setup.

With 11 out of the 12 bikes tested at Field Test having some iteration of GRX on it, you’ll know by now that it just works. This is a workhorse groupset that simply adds better ergonomics and a more suitable gearing range to what was the most popular road groupset on the market.

While the groupset blended in with what all the other bikes had, the wheels certainly stood out. This is the first bike we’ve had with Mercury wheels fitted, and the equipped G3C DISC is a quality US$799 item. With a trendy 25 mm internal width, the welded alloy rims are wider than they are deep. The pre-taped tubeless-ready rims are laced with Sapim double-butted spokes to easily-serviced sealed bearing hubs, and all told, they weigh a perfectly reasonable 1,644 g (claimed). Seriously, this is an impressive wheelset for a bike of this price.

Quality components all around.

The Zipp Service Course stem, handlebar and seatpost are in the same camp: quality, name-brand components with a proven track record. Sadly the provided stem length and seatpost setback weren’t an ideal fit for the bike, or us.

Said to be a pre-production photo sample, our tester came equipped with a long 110 mm stem, wide 440 mm bars, and 20 mm setback seatpost. And in this case, all of these added up to make the bike feel like it was a size or two larger than expected. CyclingTips’ global tech editor James Huang and I ended up testing, and enjoying, the bike with a 90 mm stem fitted, and would have preferred a straight seatpost, too.

Equally, I found the Selle Italia Novus Boost saddle and unpadded Fizik bar tape odd choices. They’re quality products, but neither really belong on this bike. Ten minutes of testing was enough for me to spin around and swap in my preferred Specialized Phenom.

But here’s the kicker. The weird stem length, set-back seatpost and bar width don’t matter. Not because it’s not important, but because Viathon’s business model is to swap out these components to your preference upon ordering the bike, all with no additional cost. And if you did want a different saddle or bartape, then they could probably arrange that, too (at a cost).

“After every order is placed, a customer service agent calls the customer to confirm the order and determine the stem and crank length, handlebar width, and seatpost offset to ensure the customer gets the best fit possible,” said Zach Spinhirne-Martin. “In some cases the customers know exactly what they want, but if they don’t then the service agent can help determine what’s best by running through a few questions about the rider and desired riding position.”

In many ways, this is exactly what a good bike store would do for you when buying a bike. But given you’d be in person with the bike store, they’d most likely have a better chance in getting the specifics absolutely dialled. And then there’s the fact that the established brands — the Giants, Treks, Specializeds and Cannondales of this world — typically supply the bikes with components that are already damn close to being right for each respective size to begin with.

All of this is in line with long-standing issues of buying bikes online. Such a purchase sight-unseen typically favours the experienced; those who know their preferred setup on a bike and understand why 10 millimetres here or there is a big deal. Viathon offers so much for the money, but there are obvious trade-offs.

What’s missing?

So the supplied contact points of the bike weren’t a good fit for us, but paying customers will at least be given the option to fix this. So what’s not to like?

Well, unfortunately, we had numerous issues with the build quality and we’re not sure if this is an issue of the actual bike, or simply an attack of the photo sample. Viathon swears it’s the latter.

Our biggest issues were certainly related to the cabling. Despite having all the good Shimano shifty bits, the full-length and low-cost Jagwire cables that connected them didn’t do them justice. The cables just felt like they were being dragged through molasses, and the full-length housing runs meant there was a fair bit of compression leading to a mushy feel at the lever. Of all the GRX bikes on test, this one shifted with the worst lever feel.

Paint rub and sluggish shifting. The cabling of this bike could certainly be improved.

Meanwhile, the rear brake hose, which sits loose inside the down tube, had a tendency to rattle against the frame. Our sample had no foam liner to silence it, but again, Viathon assured us production bikes do.

The cable routing itself was fairly basic, too. The cables rub the head tube (BYO protective frame stickers!), while James wasn’t stoked by the lack of a cable access hatch at the bottom bracket if you want to reroute or replace gear housing. To be fair, that latter element is fairly common on a number of high-end bikes and isn’t much of an issue, but it does point to a simpler frame construction.

Further build quality issues included the GRX brakes being over-filled with fluid, something that resulted in an uncomfortably short lever throw. Releasing some fluid from the system remedied this, but we can only hope production bikes don’t need the same treatment.

Bolt colour isn’t something we’d typically comment on, but then, no other brand has given us reason to before.

And then to be a little petty, our sample came with silver stainless steel bolts covering the various bidon, fender, and rack mounts. This stood out on the mostly black bike and feels like one of those small details that wouldn’t be overlooked by more established brands. Tiny issue, sure, but it’s the smallest of details that often separate great bikes from good bikes.

All of these issues, perhaps barring the selected gear cables, are things that Viathon will likely now correct before it becomes your problem. But that lack of local shop support is a risk of buying a bike through direct channels.

The other risk is the warranty. While so many of the established brands offer anything from a five-year to lifetime warranty on their frames, Viathon’s come with just two years of coverage. In reality, that’s probably enough to realise any manufacturer defects, and Viathon does also offer a crash replacement policy, but it’s something to consider nonetheless.

An impressively good imitator

In so many ways, the Viathon is like the middle manager who’s tried to mimic their boss’ style on a tight budget. They’ve taken notes about the shoes, style of jeans, shirt design, right down to the style of watch. But rather than going out and buying the exact same flashy and high-end items, they’ve sourced out the look-a-likes.

Passers-by won’t be able to spot the difference between the two, but those that own the high-end stuff will know. They’ll know you’re copying them at a fraction of the price, and if they’re really savvy, they’ll know their stuff is marginally better and the reasons why.

However, what can’t be argued with is that the law of diminishing returns certainly plays a large role in premium products, and Viathon has done a damn good job of showing that. This bike isn’t perfect and it’s not as good as the bike it’s inspired by, but none of that really matters when you consider the US$2,300 pricetag.

www.viathonbicycles.com

Viathon’s prices include shipping within the United States. Currently, the bikes are not available in other markets. Those interested in this bike should also take a close look at the Canyon Grail AL 7.0, the stand-out from our budget gravel bike test.
 
Want more gravel? Be sure to check out the rest of the content from the 2020 CyclingTips Gravel Bike Field Test. Also, be sure to subscribe to our YouTube channel so you don’t miss any of the associated videos, either.

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