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Gravel Gear

Viathon G.1 GRX 800 review

Call it a ‘Walmart’ bike if you must. But Viathon's G.1 GRX 800 is light, fast, and sporty, and costs much less than its competitors. That's a lot to love.

Review Rating


Lightweight carbon frame; Shimano GRX 800 1X11 drivetrain; ZIPP Service Course SL cockpit; affordable price


Price; rock-solid build spec; light and stiff frame


Uninspiring color choices; only has clearance for up to 700x40c tires

Size Reviewed






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You know what’s fun? Being pleasantly surprised. You know what else is fun? When that surprise comes in the middle of a bike ride. This feeling of pleasantly surprised-ness came up nearly every ride I took the Viathon G.1 GRX 800 on, although I guess there came a point at which I finally just accepted it: I really like the bike.


Who is Viathon?

Like my friend and colleague Dan Cavallari said about the Viathon R.1 road bike he tested last summer, it’s hard to separate the Viathon name from the inevitable qualifier that comes after it.

“Oh, you mean the Walmart bike?”

Yes, Viathon is backed by the Bentonville-based retail giant, and yes, that has everything to do with how such a killer build comes with such a palatable price tag ($2,298, shipped within the United States). But I’m here to talk about riding it, not about the evils of corporate America.

What is the Viathon G.1 GRX 800?

This bike is Viathon’s full-carbon gravel bike, with a high-end build for a decent price.

A quick run-though of the build shows that whoever chose the spec on this bike knew where to invest. With a Zipp Service Course SL cockpit, lightweight Mercury G1C wheelset, and bombproof Shimano GRX 800 groupset, all the important bits on this bike have been taken into consideration.

I really liked the Zipp Service Course SL cockpit, even with its lack of hipster flared bars. Photo: Courtesy Viathon

The angles on the G.1 GRX 800 are closer to that of an endurance road bike than a hardtail mountain bike, yet the bike can still handle rough, off-camber ascents and descents. The bike has been compared to the Santa Cruz Stigmata, and I found that most of the geometry was identical: The 52cm G.1 GRX 800 that I tested has a 71-degree head angle, 74.5-degree seat tube angle, and 425mm chainstays — all the same on the 52cm Stig.

The geometry will lead many to believe that the G.1 GRX 800 is more of a competitor than an adventurer, but I found the bike capable in myriad conditions. Coronavirus robbed me of the opportunity to race on it, but that would have been fun, especially on a course like the Crusher in the Tushar with its dynamic blend of brutal climbing, gnarly descending, and sandy flats.

The stiffness and feathery weight of the G.1 GRX 800 make it an excellent climber, but I was amazed at how well it also descended.

Unfortunately, the tire clearance on the G.1 GRX 800 (only up to 700 x 40, or 650b x 2.1) is a limiting factor, conflicting with my opinion that the bike is just as capable of adventure, as on a race course. However, the stock 700×40 IRC Boken tires paired with the wide Mercury G1C carbon rims give the bike a much wider footprint — which I definitely appreciate when I’m out in the woods.

How does the G.1 GRX 800 ride?

I expect a lot out of my gravel bikes, and perhaps that’s unfair given that they don’t all seek to achieve the same ride characteristics. Blame COVID, though — given the crowded mountain bike trails, caution around travel, and work-from-home funk, I’ve definitely been pushing the limits of my afternoon rides from home.

From 5,480 feet to 9,480 feet: The G.1. GRX 800 can go a lot further than it looks.

I took the G.1 GRX 800 on all of the surfaces that at some point constitute a gravel ride for me — pavement, hard-packed dirt roads, a bit of gravelly singletrack, and — just this one time — a really gnarly 4×4 road in the mountains. The bike didn’t bat an eye at any of it.

Although it’s certainly stiff, I didn’t feel nearly as battered as I do when I’m riding my personal Ibis Hakka MX through chunky rock gardens. Furthermore, that stiffness lends a lot of good, predictable characteristics to the bike: It picks up speed quickly and responds to cornering and other moves. How do I know this? I was able to keep up with Ben Delaney on our dawn patrol ride to the Gold Hill Store. If he says he was just being nice, don’t listen.

The real darling of the G.1 GRX 800 is its namesake: The gravel-specific Shimano GRX 800 drivetrain. The bike comes stock with 1×11 gearing, and the 46T chainring paired with a 11-42T cassette gave me the range I needed and the simplicity I prefer when riding varied, off-road terrain. The asymmetric chainstays allow for 50/34T 2x gearing, as well.

The above factors make the G.1 GRX 800 an excellent climber, but I found it just as capable on the descents. That one sketchy 4×4 road in the mountains? I was amazed at how the dropped seatstays kept the bike compliant when it could have been squirreling all over the place. My upper half stayed put and comfortable with the Zipp Service Course SL cockpit; even though the bars don’t have any flare, I appreciate aluminum on some of the rougher riding I do.

A gravel bike test is not complete without a sketchy, loose descent.

G.1 GRX 800 verdict

There are a few superficial things about the G.1 GRX 800 that I have to comment on because buying a bike, at any price point, is about personal expression to some degree. Unfortunately, this bike is lacking is the style department. It’s only available in two, very ‘meh’ color schemes (the matte black/copper shown in the photos, or an equally uninspiring matte black/silver).

The name leaves something to be desired, as well; as both a former healthcare professional and nerdy wordsmith, I have a real aversion to made-up pharmaceutical drug names — and this sounds dangerously close to being one.

Nevertheless, my decidedly superficial criticisms of the bike do not hold a candle to how much I believe that the G.1 GRX 800 is a great bike, and not just ‘for the money.’

The carbon frame feels stiff and fast, handles terrain from pavement to gravel to singletrack with confidence, and boasts excellent spec where it matters. Like I said, the first few times I rode the G.1 GRX 800, I was surprised at how capable it was. I had been influenced by the Walmart stigma and the astounding price point. Then, I got over it and I started treating the bike just like I do every other one — no mercy, no sympathy, no holding back. We got along just fine.