ARC8 Eero gravel bike takes inspiration from rally racing – fast on tarmac, as fast on gravel

Arc8’s new Eero gravel bike is designed to carry aerodynamic speed on the road and keep up the pace as it heads off road onto gravel. They call the Eero inspired by rally racing, where the transition to loose surfaces just ups the fun factor of a bike still comfortable with going fast over any surface, and happy to drift through loose gravel corners…

ARC8 Eero lightweight, aero carbon gravel road bike

The lightweight, aerodynamically optimized gravel bike shares a lot with recent aero bikes- from racy geometry to airfoil tubing and fully internal cable routing from their Escapee road bike. But of course, longer chainstays and room for larger tires work together with versatile mounting points to create a gravel-ready bike.

Arc8 wanted to make sure that the new Eero retained all of that fast road bike feel, without trying to be an off-road dropbar mountain bike just to let you go farther away from tarmac. Their thinking is that the best gravel rides spend a lot of time on the road too, so compromising on-road speed & efficiency was out of the question.

Aero Gravel Road Geometry

The ARC8 Eero comes in just a four frame size range (S-XL) down from five on ARC8’s road bikes, mostly covering the larger sizing spectrum where geometry isn’t compromised by the larger tires. Frame reach figures generally run close to their 51-60cm road bikes, but with 3-4cm higher stack for more upright off-road position. The angles are slackened back about one degree and chainstays grow almost two centimeters to deliver confident handling over mixed surface riding.

Gravel Tech Details

The end result, the Eero is essentially an endurance all-road bike (inspired by their Escapee), but with room for up to 700c x 50mm tires, and with full-coverable fender compatibility and mounts for extra cages/bags under the downtube & on top of the toptube. Dropped seatstays add a bit more vertical compliance in the frame, and together with a rear wheel cutout, are said to help reduce drag on the rear end of the bike.

Arc8 says the claimed Eero raw frame weight is 950g, or 1120g painted (M) while keeping stiffness on par with their Escapee. Fork weight comes in 380g raw, 425g painted and uncut. Built-up as it is shown here with a GRX Di2 double, this complete bike would weight 8.36kg.

The Eero features modular, completely internal cable routing, a round 27.2mm seatpost, a BSA threaded bottom bracket, is compatible with 1x or 2x drivetrains (mechanical or electronic) thanks to a removable front derailleur tab, flat mount discs & 12mm thru-axles, and gets rear rack & full fender mounts.

ARC8 Eero gravel bike – Pricing & availability

The Eero is being sold only as a frame kit now for 1990 Swiss Francs (~$2180 or 1845€), including: frame, for, set clamp, axles, headset, expander, alloy handlebar, alloy stem, top cap, and routing accessories. Arc8’s recent Faserwerk forged carbon seatpost is available for an extra 149CHF. It is available exclusively in this limited edition gray now in just medium & large sizes.

Full availability is slated for February 2021, where the frameset will be offered in blue, pink, and a raw ready-to-paint carbon finish. Custom paint direct from Arc8 will also be available at that time.

ARC8 apparently got so excited about the idea of continuing speed from asphalt onto gravel that they made up a completely fictional Finnish rally driver to justify the name of their new bike – apparently blending together Eero Nuuttila & Kyösti Hämäläinen (who together won 16 national rally championships from 1970-1986. The created the fake Eero Hämäläinen name and quoted him at length…

Arc8 Eero gravel bike, lightweight aero carbon fast gravel road bike, Egelmair Photography

“When you go from tarmac to gravel, your impression is that your speed is much higher than it really is. It is exciting. I got into kind of a superhero mode, it felt unreal. The faster I went, the more this feeling of being an invincible superhero flying along the road grew. So I was just stomping it.”

ARC8bicycles.com