Curve Kevin of Steel 4: A Steel Gravel Bike Built for the Long Haul (Literally)
Curve's Kevin of Steel 4 returns with 29x2.4" clearance, 5 bottle mounts, and geometry built for loaded riding. Pre-orders open now for early 2027 delivery.
Steel gravel bikes occupy a strange space in the market—too heavy for the weight-obsessed, too slow for the race-focused, yet somehow the right answer for riders who actually want to keep a bike for a decade. Curve Cycling's Kevin of Steel 4 leans hard into that identity, and the spec sheet suggests they've thought carefully about what long-haul versatility actually requires.
The Numbers That Matter
Tire clearance tells you what a bike is actually for. The KOS4 fits 29 x 2.2" in the rear and 2.4" up front—firmly in the territory where you stop worrying about gravel chunk and start eyeing singletrack. That asymmetric clearance isn't an accident; a larger front tire improves steering traction without the chainstay compromises of matching rear clearance. For anyone juggling a single bike across road-adjacent gravel and rougher stuff, this opens options.
The geometry mirrors Curve's GXR4 platform: slack enough (70.6°–71.6° head tube angle depending on size) to stay composed when things get loose, with stack numbers that climb meaningfully on larger frames. A size Large gets 608mm of stack. If you've spent years cramming spacers under your stem because modern gravel bikes assume you're a yoga instructor, this matters.
Mounts, Mounts, Mounts
Five bottle mounts including offset positions on the down tube. Rear rack mounts. Fender mounts. Top tube bento mounts. The Ride 415 VGM fork carries 17 pounds per leg. This is a bike designed for people who actually load their bikes—commuters, bikepackers, parents hauling snacks for a kid's soccer game on the way home from a gravel loop. The offset down tube mounts let you run three bottles with a full frame bag, which sounds minor until you've spent a hot century rationing water because your bag blocked the second cage.
The Wait and the Cost
Framesets ship early 2027. That's not a typo—you're putting down a 50% deposit now for a bike that arrives in roughly 18 months. At $2,999 AUD (roughly $1,950 USD at current rates), the price has jumped from the previous version's $2,399 AUD. You get the frame, fork, axles, headset, and clamp, but you're still sourcing your own groupset and wheels. For a steel frameset, that's not cheap, though it includes the cargo-capable fork that would cost several hundred dollars standalone.
The dropper post port and UDH rear dropout are smart updates—the former because no one wants to drill their own steel frame, the latter because SRAM's universal hanger actually delivers on the "find a replacement anywhere" promise. External cable routing keeps maintenance simple, which matters more on a bike you intend to keep through multiple drivetrain generations. Whether the 18-month wait makes sense depends on how patient you are and how badly you need a new bike. If your current rig works, this is the kind of frame worth waiting for. If you're bikeless or desperate, that's a long time to stare at a deposit receipt.
Ollie Jones
