BUILD: Curve Kevin x Shimano GRX

This is our second edition of our bike build series, in which we feature the latest goods and/or the fruitiest parts, then build up a unique frameset. To be honest, we have had the Curve Kevin frame set hanging around in the garage for far too long. So, when the announcement came for the new Shimano GRX (gravel group set), I knew it would be the perfect match. After a few emails, brews and meetings, we finally got a delivery of the new GRX group set from Shimano.




The Concept

I wanted to build a bikepacking bike that could be taken anywhere. Lately, the routes I’ve been devising are not just on sealed and gravel roads, but can be anything from access roads and 4WD tracks to walking and mountain bike trails. As I search to get deeper (beyond the gravel roads) and further into the backcountry, it’s become evident that I need a more capable bike. I basically want a do-it-all bikepacking bike that I can take anywhere, at any time. It needs to be functional, take a ton of abuse, and be a pleasure to ride (for hours and days at a time). The main function would be to have this rig parked up and ready for hauling. It’s not too dissimilar to an off-road 4WD, parked up and ready for adventure, with a snorkel, raised suspension, mud-flaps and big tyres. Ultimately, and above all, the bike must be robust and incredibly reliable.

I’ve had past experiences where bikepacking trips have gone sideways. These learnings have lead me to think about my equipment. When you’re on a trip in the middle of nowhere, guess what – there’s no bloody bike shop (or even a dairy sometimes)! One trip, last summer, my wife and I ran into problems and were both made to limp home for the last two days of the trip. My wife had her derailleur turned inside by a bit of driftwood, and I had my Shimano Dura Ace Di2 gearing fail, with wiring issues, after seven odd hours hike-a-biking and riding across some severe mountainous terrain. Of course, there was nothing that could be done with the derailleur as these things can happen, but the Di2 wiring was an issue. Not to mention, sometimes having to carry the charger in-case the battery loses charge. So, for this build I wanted mechanical gearing; being able to fix something whilst in the back of nowhere, is a must!




The Bike

Gravel bikes have exploded onto the market over the past few years. I needed this rig to be capable, reliable and robust for any adventure thrown at it. For me, the frame material choice was always going to be steel. The archetypal frame material, steel has been around since the earliest days of cycling and while riding a steel frame bicycle has a certain romanticism to it, the steel bikes of today are a far cry from their heavy ancestors of yesteryear. Today’s steel frame bikes embody the perfect balance of ride quality, durability, repair-ability, environmental sensitivity, design flexibility, and aesthetics. Our Trans-Tasman friends at Curve, an alty boutique bike company, that is fundamentally about adventure riding and community, have developed the Kevin; what a name?! As I’ve become familiar with this bike, I’ve renamed it to:; Uncle Kev. This version is the Kevin of Steel (they have another version which is Titanium) and the steel is none other than Italian-made Columbus tubing; the masters of frame building.

Firstly, the tyre clearance is built to handle anything from a from 700c 28-45mm to 650b (27.5”) with 2.2” rubber. This means you can effectively have two bikes in one. My main purpose, however,was to have this rig ‘adventure’ – so, the biggest rubber possible! The frame has also been well thought- out for hauling, as there’s rack and fender-ready frame and fork micro-panniers. The Curve Ride and Seek fork carries up to six kilograms of cargo for those longer adventures.


Long geometry has been utilised to offer extra stability and better control when the terrain gets rough. Also, Curve suggest running a shorter stem to better control and to get rowdy on the trails. I went from a 120mm to 100mm stem. There’s also a high standover, which improves frame stowage space and another good feature is the three water bottle mounts, perfect for bikepacking trips. Electro-deposition plating uses electricity to deposit a smooth, thin, uniform layer of plastic coating to the frame surface;. Iideal for protecting the frame on rugged adventures.




The Parts


No one does reliable better than Shimano. They’re not always changing the game, and occasionally you get the feeling that they’re chasing other manufacturers, but when they do release new products, 99 times out of 100 you can guarantee it’ll be reliable and simply do what it’s supposed to do. When we caught wind of Shimano’s new GRX groupset it was the obvious choice for this build.


GRX is Shimano’s first dedicated gravel groupset and, true to form, they gave the gravel scene a couple of years to really develop before jumping on the train and putting out a dedicated gravel product. Shimano decided not to tell riders what they needed for gravel, and instead chose to wait for riders to tell Shimano what they wanted. The result is a groupset that takes learnings from road and mountain bike component lines and sandwiches them all into a component line that’ll make your wildest gravel dreams come true.

Mullet (pronounced moo-lay – stay classy) builds are one of the hottest gravel trends right now. For those not in the know, a mullet build is basically just road shifters paired up with a mountain bike derailleur so you can take a bigger cassette. With GRX you no longer have to mismatch groupsets; their longer cage derailleur will accommodate up to a 42T cassette. With options to run dropper posts and single or double chainring setups, Shimano have really taken a good look at what the gravel market wants.


Shimano GRX is available in either mechanical or Di2 with hydraulic disc brakes. In this case, we opted to run a mechanical groupset mostly to give us options in those shit-hits-the-fan moments and, let’s be real, mechanical groupsets are so good nowadays that the extra coin to go electronic just wasn’t worth it. Cheaper and easier to fix replace all the things we like on a bike that’s going to see some incredibly remote places and take a hammering.

The rest of the components were selected with strength in mind. From the get-go we knew this bike was going to be heavy, not only due to the steel frame but also because most of the time it’ll be loaded up with