Black Series Corsa SL Review: A 5.24 kg Claim Under the Microscope

Introduction

Black Series is a new British brand, and the Corsa SL is its featherweight road bike. The headline figure is 5.24 kg for the complete bike in full tubeless trim. The special edition build shown here tips the scales at 5.38 kg in size medium, and that is with standard butyl inner tubes, so there is still a little weight left on the table.

The number lands in a season where lightweight road bikes are firmly back on the agenda. Scott has an all-new featherweight Addict RC, and Specialized has launched the Aethos 2. The Corsa SL is built to go lighter than both, and it does so with a level of component detailing that is unusual even in this part of the market.

Who This Bike Is For

This is a bike for riders who treat weight as the headline specification. If you want the lowest possible complete weight from a production road bike, and you are comfortable with a build that leans on specialist carbon parts, the Corsa SL is aimed squarely at you. It is also a bike for riders who enjoy the engineering story behind the numbers: the frame, the cockpit, the cranks and even the thru axles are all part of one weight-reduction exercise.

It is not a value proposition. Riders who want a light, fast all-rounder at a mainstream price will find more sensible options elsewhere, and the 36 mm tire clearance is worth noting if you prefer a little more volume under you. The Corsa SL exists for the rider who wants the number.

Frame and Construction

The Corsa SL frame is a single monocoque built with a dual mold process. An external mold is matched to a solid internal form rather than an inflatable bladder, and once the frame is molded that inner form is dissolved. The method reduces excess material and leaves the internal surfaces as smooth as the outside, which matters on a frame this light.

The frame weighs 597.5 g and the fork 348 g, both in size medium. Those are competitive figures given what the frame has to accommodate: full internal routing, a threaded T47 bottom bracket shell and clearance for tires up to 36 mm. For context, the Scott Addict RC frame is quoted at 640 g and the Specialized Aethos at 595 g, so the Corsa SL sits right at the sharp end of the category.

Cockpit, Cranks and Wheels

The one-piece cockpit was developed with German lightweight specialist Schmolke. It pairs a 42 cm bar with an equivalent 110 mm stem and weighs just 220 g.

The carbon crankset is a collaboration with carbon specialist THM. It weighs 289 g in a 172.5 mm length, and the carbon side chainring adds a further 112 g.

The wheels look conventional at first glance, with a 28-spoke build, but the numbers are anything but. The rims weigh 280 g each and are laced with Sapim CX-Ray spokes to the brand’s own ultra-light hub set, which comes in at 64 g at the front and 149 g at the rear. The complete pair weighs 1,081 g including the tubeless rim tape, a figure that very few wheelsets can match.

Tires, Hardware and Small Details

The wheels are wrapped in Tufo Comtura Prima tubeless tires at 220 g each in a 32 mm width. That is a road-worthy width rather than a pure climbing-specialist choice, and the build is clearly designed around good quality road tubeless rubber.

The finishing kit follows the same philosophy. The Corsa seatpost, another THM collaboration, weighs 85 g, and the Black Series Corsa saddle comes in at 43 g. Even the thru axles are bespoke: a molded carbon shaft with a ceramic insert for the hex key slot and a keyed metal threaded end piece bonded onto the shaft. The rear axle weighs 17 g and the front 15 g, and they are designed to work just like standard thru axles. The bottle cage bolts are carbon fiber sourced from the aeronautical industry, and a set of four M5 by 15 mm bolts weighs 2 g.

Ceramic bearings are used throughout, and the build includes a CeramicSpeed OSPW. Worth noting, that oversize pulley system adds weight compared with the standard SRAM Red pulley wheels.

Things to Consider Before Buying

The most obvious consideration is price. Expected retail is around £16,000, which is roughly $21,650 or €18,350, and availability is expected at the end of the year. That places the Corsa SL firmly in halo-product territory, and it is worth being precise about the headline figure: 5.24 kg is a claimed weight for the full tubeless build, while the build shown here weighs 5.38 kg with butyl inner tubes fitted.

It also pays to read the spec sheet closely rather than assuming every part was selected purely for the scale. The CeramicSpeed OSPW is a case in point, since it adds weight over the standard SRAM Red pulley wheels. Tire choice matters more than usual too: the build uses a 220 g tubeless tire in a 32 mm width, and the overall figure depends on keeping that approach.

Buying Advice

If you are shopping at this end of the market, the decision usually comes down to which part of the weight story you care about most. The Corsa SL spreads its advantage across the whole bike: a 597.5 g frame, a 348 g fork, a 220 g cockpit, a 289 g crankset and a 1,081 g wheelset. The Scott Addict RC and the Specialized Aethos 2 are the natural reference points, and their quoted frame weights of 640 g and 595 g show how close the top of this category has become.

What the Corsa SL adds is the depth of the detailing: carbon thru axles at 15 g and 17 g, an 85 g seatpost, a 43 g saddle and a 2 g set of bottle cage bolts. If that level of attention is what you are paying for, the bike delivers it in a way that few others do. If you simply want a light road bike and the budget is a real constraint, the sensible move is to look at the wider category first and come back to the Corsa SL only if the last few hundred grams are genuinely the point.

Conclusion

The Black Series Corsa SL is a statement build from a new British brand. A 597.5 g frame, a 1,081 g wheelset and a claimed 5.24 kg complete weight in tubeless trim put it at the front of the lightweight road bike conversation, and the detailing runs all the way down to the thru axles and the bottle cage bolts. The trade-offs are equally clear: an expected price around £16,000 and availability at the end of the year. For riders who measure a bike in grams, that is likely to be a trade worth making.