Arc8 Essential

In the autumn of 2021 I was working with a customer to build a lightweight hardtail suitable for marathon and stage races. In particular, the Croc Trophy was (at the time) only a few months away and was set as the deadline for this particular build.

Unfortunately COVID constraints had ruled out bigger brands, so together we went searching for alternatives, looking far and wide for small-scale manufacturers of lightweight carbon frames suited to the task.

Most boutique manufacturers tend to fall into the trail/enduro category. A steel hardtail wasn’t going to cut it, whilst a 140mm-160mm trail bike was complete overkill. Being a fan of the XCO World Cup, I ran through the bike sponsors for each team, researched brands and contacted manufacturers… and for the most part came up blank. Some frames had long lead times, whilst other brands simply weren’t interested in shipping to Australia. In the end the customer found a Niner Air9 frame and we went from there. That build however, is the subject of another article.

This didn’t stop me looking though. With lead-times for some frames blowing out to 2023, I knew it was essential to find other suppliers of high quality, lightweight frames for cross country.

I’d come across a PinkBike article about a small company called Arc8, started by a few Swiss friends who’d previously worked for big bike brands and had extensive experience working directly with Taiwan carbon manufacturers. What impressed me most was their ethos of making lightweight bikes they’d want to ride themselves.

Around the same time I had a delivery date for a customer’s bike blow out by around 6 months. I gave her the option of waiting (with more potential delays), issuing a refund, or doing a full custom build around an Arc8 frame. I’m glad to say that the client put her trust in me and chose the 3rd option.

The original briefing for a bike was for a fast rolling yet comfortable MTB. It was replacing an 11 year old (but high spec) Merida Ninety-Six, and the new bike had to be at least as light. Arc8’s Essential frame – a 120mm travel light trail / downcountry frameset – weighed in under 2000gm, so seemed like the perfect basis for the build.

The client’s son – also an avid rider – happened to have just swapped out a set of 120mm Rock Shox SID Ultimates for something larger on his own bike. No longer having a use for SIDs, he donated them to the build.

Keeping to a budget, drivetrain duties were handled by a cable-operated (“non electric”) SRAM XO1 derailleur and shifter, with a Garbaruk 10-52t cassette being driven by an XO1 chain and GX Eagle carbon cranks (with an XO1 chainring… just to save a little weight over the stamped-steel GX version).

The wheelset – as always, handbuilt in-house – with DT-Swiss 350 hubs paired with Duke’s Lucky Star Ultra alloy rims. Whilst carbon is the material du jour for lightweight rims, the Lucky Star Ultras are both lighter (360gm) and wider (24mm internal) than many carbon XC rims without needing to under-tension spokes (I’m looking at you Stan’s Crest). All up the wheels came in under 1500gm. WolfPack Race tyres (29×2.4) are fast rolling yet grippy, but most of all, light – coming in under 700gm each.
Brakes were SRAM Level TL with Centreline 2 piece rotors.

Perhaps one of the most eye-catching features of the build was the one-piece bar/stem. This particular set also came from Arc8, under their Faserwerk component line. More weight was saved with the BikeYoke Divine SL dropper (80mm travel) – one of the most impressive things about the BikeYoke droppers though is not the weight, but the build quality. These are one of only a few brands which don’t seem to develop play after a few rides… something that is, unfortunately, the reality with most droppers. An SQLab 611 saddle and ESI FIT CR grips provided the contact points.

In the end the build came out lighter than the Merida it was replacing. More than that though, the bike was far more capable. Modern geometry, long yet efficient travel, a dropper post – and 29″ wheels – mean that bike’s owner will be able to ride faster, further and on more challenging terrain. The fantastic build quality of the frame and components, along with the simplicity of a 1x drivetrain mean that the Arc8 Essential is going to last for at least as long as its predecessor as well.