This is the world's lightest steel road bike | 5.42kg of marvellous metal

The Yasujiro Svelte is a refreshingly simple and actually usable weight weenie special that has won the collective heart of BikeRadar

Jack Luke / Immediate Media

Published: September 9, 2019 at 6:12 pm

This Yasujiro Svelte weighs just 5.42kg, which we reckon makes it the lightest steel road bike in the world.

Yasujiro is the in-house bike brand of tubing manufacturer Tange.

This frame is constructed from the brand’s premium double-butted Ultimate tubing. The walls of this tubing are a mere 0.35mm thick (!) at their thinnest point. This ultralight tubing is at the heart of this remarkable bike and we are utterly in love with it.

Yasujiro Svelte — world’s lightest steel road bike specs

  • Frameset: Yasujiro Svelte, Tange Ultimate tubing, Be King carbon fork
  • Groupset: SRAM Red eTap with RED 22 crankset and Be King chainrings
  • Brakes: Cane Creek EE brakes
  • Finishing kit: Be King carbon
  • Wheels: Be King tubular
Yasujiro Svelte the world's lightest steel road bike
Unpainted, the 52cm frame weight just 1,240g. - Yasujiro

The Svelte frame is delightfully simple, with only a few small modifications made to the frame components to reduce weight, bringing this 52cm frame down to just 1,240g (unpainted weight).

The build of the bike is (no surprise) fairly premium, but it doesn’t feature nearly as much crazy carbon exotica as you might imagine.

Yasujiro Svelte the world's lightest steel road bike
The finishing kit has been painted to match the frame. - Jack Luke / Immediate Media

The shallow tubular wheels, seatpost, saddle, bars and stem all come from Be King, which appears to be an OEM frame and component supplier based close to Yasujiro.

Details on the seatpost and handlebars have been painted to match the delightful salmon-y light-ish pink colour of the bike.

Yasujiro Svelte the world's lightest steel road bike
Svelte by name and nature. - Jack Luke / Immediate Media

As the most millennial-y millennial on the BikeRadar team, it should come as no surprise that I immediately fell for this pastel hue when I first glanced at it from across the hallowed halls of Eurobike 2019.

Yasujiro Svelte the world's lightest steel road bike
There are not enough bars wrapped with cotton tape. - Jack Luke / Immediate Media

The bars are wrapped in a lovely thin, black, cotton bar tape. Running no bar tape would, of course, be lighter, but I appreciate this nod towards practicality.

Yasujiro Svelte the world's lightest steel road bike
The bike is built around a SRAM Red eTap groupset. - Jack Luke / Immediate Media

The bike is built around a previous generation SRAM eTap 11-speed groupset, though, curiously, Yasujiro has opted for an older RED 22-era crankset. These are finished with a set of lightweight chainrings, which also come from Be King.

In a most welcome but rather rare move for a weight weenie bike, the bike features a threaded bottom bracket shell.

Most press-fit bottom bracket systems are lighter than traditional threaded bottom brackets but, as we all know by now, these can be a nightmare to live with.

Yasujiro Svelte the world's lightest steel road bike
The bike has small cutouts in the base of the bottom bracket to reduce weight. - Jack Luke / Immediate Media

Small windows have been cut out from the base of the bottom bracket shell to shave precious grams.

Simple slimmed-down external stops for the rear brake cable are also used to shave weight over internal routing.

Yasujiro Svelte the world's lightest steel road bike
The straight 1 1/8in steerer matches the tubing perfectly. - Jack Luke / Immediate Media

Yasujiro has opted for a traditional straight 1 ⅛in steerer with an external headset for the Svelte.

I personally welcome this because it complements the skinny profile of the bike’s main tubes better than a modern chunky, tapered head tube.

Yasujiro Svelte the world's lightest steel road bike
Cane Creek's EE brakes offer super strong braking in a lightweight package. - Jack Luke / Immediate Media

No lightweight build is complete without a set of lightweight brakes and Yasujiro has opted for a set of Cane Cree EE brakes.

We’re big fans of these feathery calipers here at BikeRadar because they offer remarkably strong braking in a ludicrously light package.

The true weight weenie in me sees plenty of opportunities to trim weight from this build — a 1x drivetrain, a lighter crankset and removing the steerer bung are all obvious places to start. However, I appreciate the practicality of the bike as it currently stands.

Yasujiro Svelte the world's lightest steel road bike
It was refreshing to find such a simple and beautiful frame at Eurobike. - Jack Luke / Immediate Media

It was also a breath of fresh air to see such a simple and handsome bike among a sea of ‘dropped seatstay this’ and ‘aero formed that’ at Eurobike.

Yasujiro Svelte the world's lightest steel road bike
Tange Ultimate tubing is some pretty special stuff. - Jack Luke / Immediate Media

That it's such a lovely looking thing while pushing the boundaries of what’s possible with a steel frame is nothing short of remarkable.

The Yasujiro Svelte frameset is available now and will cost approximately $1,600. International pricing and availability is not available but the bike will be available through the brand’s network of international distributors.

Note: I have searched extensively to make sure this really is the lightest steel road bike. However, it is entirely possible that in some hidden corner of the internet, reports of something even lighter exist. Please let me know if you're aware of something lighter in the comments!