With the ARC8 Eero, the young Swiss company aim to stir up the gravel bike market. We had the opportunity to test their brand new bike extensively before its launch. How does it compare to the competition?

A quick overview of this group test: The best gravel bike 2021

ARC8 Eero | 8.44 kg (size M)| € 4,175 | Manufacturer’s website

The ARC8 Eero isn’t just here to add a breath of fresh air to the gravel sector with its fancy paintwork – the Swiss bike also has a lot of clever tech to offer. The carbon frameset comes with a threaded BSA bottom bracket, bosses for up to four bottle cages as well as mudguards at either end and a specially developed cockpit. The extra-wide handlebar clamp allows the cables to be routed internally via the ARC8 ICH stem. The four Allen bolts, there backward orientation and small size mean mounting the handlebar requires you to be a bit more careful than with conventional solutions, but it delivers both form and function. After entering the stem, all cables remain hidden inside the frame. We only heard the cables rattle inside the frame faintly on very rough surfaces. The 1×11 Shimano GRX RX815 Di2 groupset is an excellent fit for the Eero. In combination with the 11–42 t cassette, the 40 t chainring requires a lot of physical effort from the rider on steep climbs but it’s fine for the bike’s more competitive aspirations.

The wide handlebar clamp allows the cables to enter the frame through the stem. It’s nice to see bike brands keep innovating. Our only problem with this solution is that the GPS computer can no longer be mounted centrally in front of the stem with conventional mounts. #cockpitocd
You might not have any problems with size 42 shoes but that’s not the case with size 46 ones. If you’ve got big feet, toe overlap can be an issue with the Eero.

ARC8 Eero

€ 4,175


Seatpost Faserwerk Seatpost 0 mm
Brakes Shimano GRX RX810 160/160 mm
Drivetrain Shimano GRX RX815 Di2 40 (11–42)
Stem ARC8 ICH Stem 100 mm
Handlebar Zipp Service Course SL-70 XPLR 420 mm
Wheelset ARC8 C38
Tires Schwalbe G-One Allround 40C

Technical Data

Size S M L XL
Weight 8.44 kg
Wheelsize 700C

Specific Features

Self-engineered stem with wide clamping area and cable-routing
bolting points on the topside of the toptube and the downside of the downtube
bolting points for a mudguard

The Shimano GRX RX815 Di2 groupset allows you to shift gears quickly and accurately in every situation. The gear ratios on the ARC8 demand strong legs on long climbs.
The frameset offers clearances for up to 700 x 50C tires. Bigger tires would improve the bike’s overall comfort significantly.
Size S M L XL
Seat tube 510 mm 550 mm 570 mm 600 mm
Top tube 525 mm 545 mm 564 mm 583 mm
Head tube 137 mm 157 mm 170 mm 197 mm
Head angle 70.0° 71.0° 71.0° 71.0°
Seat angle 73.5° 73.5° 73.5° 73.5°
Chainstays 420 mm 420 mm 420 mm 420 mm
BB Drop 75 mm 75 mm 75 mm 75 mm
Radstand 1,002 mm 1,012 mm 1,032 mm 1,053 mm
Reach 364 mm 376 mm 388 mm 400 mm
Stack 545 mm 568 mm 593 mm 618 mm

A really fun bike for high-intensity, fast all-road and gravel rides! Configured as it is here, the Eero lacks the comfort necessary for long-distance adventures.

Helmet Oakley ARO3 | Glasses POC Aspire Clarity | Jacket POC Men’s Signal All Weather Jacket
Shorts Jeans Second Hand | Socks VOID Socks 16 | Shoes Giro Empire VR90

For the wheels you get ARC8 C38 carbon rims laced to DT Swiss 350 hubs. Our test bike came fitted with Schwalbe’s 700 x 40C G-One Allround tires. You could happily exchange these for higher-volume slicks or semi-slick tires to make the overall system a little faster and more comfortable, given the maximum tire clearance of 700 x 50C. In size M, this configuration of the Eero weighs 8.44 kg and costs € 4,175.

Out of the gate, it’s clear that the Eero just wants to go! It feels light-footed and direct as it’s brought up to speed and it’s an excellent all-rounder for going fast both on flat terrain and in the mountains. The only drawback is that when the road gets bumpy, the Schwalbe tires and the comparative lack of compliance mean that the bike will occasionally lose traction, not always transferring your braking or pedalling power to the ground.

The wide clamp of the stem, the aluminium Zipp Service Course SL-70 XPLR handlebar and the Faserwerk carbon seat post don’t add to the bike’s comfort. The bike’s vibration damping is okay but overall rider comfort isn’t on par with the other bikes on test. However, the good thing about the level of feedback is that in rough terrain, the bike will quickly let you know what you’re getting into, letting you be prepared. The handling of the ARC8 has a lively and playful character, which becomes increasingly stable as you pick up speed. At slower speeds, the agility of the front and rear are well matched. When riding fast, the front tends to respond to input from the rider quicker, with the rear lagging behind slightly. At high speeds, you need to be firm with the bike in order to navigate a corner without having to correct your line halfway through. However, this behaviour doesn’t necessarily compromise the rider’s confidence: on steep climbs and at slow speeds, the agile handling up front allows you to balance out your own body movements while the bike’s stable handling at high speed instils you with confidence.

Tuning tip: higher-volume and ideally (semi-)slick tires that match the speed of the bike and generate a little more comfort

Riding Characteristics



  1. cumbersome
  2. playful


  1. nervous
  2. confident


  1. demanding
  2. balanced

Fun factor

  1. boring
  2. lively


  1. firm
  2. comfortable

Value for money

  1. terrible
  2. very good

Technical Data


Size: S M L XL
Weight: 8.44 kg
Price: € 4,175

Indended Use

Smooth tarmac 1
Allroad/Gravel 2
Everyday/Commuting 3


The ARC8 Eero is a great bike for fast after-work rides. Its slightly too aggressive nature and the comparative lack of comfort with the rest of the group are its only shortcomings. As a result, it has limited suitability for long-distance use. Ambitious gravel racers will find a lively bike with plenty of tire clearance, cleverly integrated cable routing and a fresh look. Those who prefer cruising are best advised to look elsewhere.


  • coherent, race-oriented concept
  • quick acceleration
  • fun handling at slow and medium speeds
  • lots of tire clearance
  • clean cable integration


  • increasing chance of toe overlap for those with big feet
  • the rear lags behind the front at high speed
  • lack of comfort

Not sure which gravel bike you should buy? This guide will help you for sure: gravel bike buyers guide.
You wonder what tires to put on your gravel machine? We recently tested the best gravel tires against each other in our gravel tire group test.

Get more information here: arc8bicycles.com

The testfield:

Get an overview of this group test: The best gravel-bike 2021 – 13 models on review

All bikes on review: 3T Exploro Race EKAR 1X13 (Click for review) | ARC8 Eero | BMC URS 01 ONE (Click for review) | Cannondale Topstone Carbon Lefty 3 (Click for review) | Canyon Grail CF SLX 8 eTap (Click for review) | Fustle Causeway GRX600 (Click for review) | OPEN WI.DE. (Click for review) | Ridley Kanzo Fast (Click for review) | Ritte Satyr (Click for review) | ROSE BACKROAD FORCE ETAP AXS LIMITED (Click for review) | ROSE BACKROAD AL GRX RX600 1X11 (Click for review) | Specialized S-Works Diverge (Click for review) | Trek Checkpoint (Click for review)

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Words: Photos: Valentin Rühl