Lightest road bikes 2025 — fantastically featherweight rides that barely tip the road.cc scales of truth

The Aethos Pro Ultegra Di2 is one of the lightest road bikes we have ever reviewed on road.cc at just 6.66kg. Specialized's S-Works model goes even lighter, with a 56cm frame weighing just 585g!

If you are not overly bothered about aerodynamics and just want minimal weight then Liam described this Aethos as the gold standard for general road bikes.

He found it to be a climber's dream with the way it floated up any sort of incline, and Specialized have also nailed the handling for when you are coming back down the hill, although the handling could be considered quite twitchy for some.

So, the price is high, but if you want one of the lightest mass-produced bikes on the market then the Aethos pretty much has you covered. As already mentioned, we reviewed the Pro version but you can go even lighter (under 6kg) if you have deeper pockets by getting the S-Works model, yours for £12,000 at the time of writing.  

Aero bikes aren't renowned for their low weight, built even with its oversized tubing, electronic groupset and deep section wheels, this model is less than half a kilo over the UCI weight limit at just 7.35kg.

When Aaron recently reviewed this bike he described it as possibly one of the best all-round aero road bikes that are available right now due to it being ridiculously fast yet super-easy to live with as an everyday bike. The highlights being a very stiff frame which also passes on plenty in terms of feedback to the rider, while the front end geometry gives fun and direct handling in the bends.

It may not be the top-end bike in the Foil line-up, but this Pro model still comes equipped with the latest Dura Ace Di2 groupset, fully integrated carbon fibre handlebar and stem, plus Shimano's C50 deep section wheels.

If aero is your thing but you don't want a weight penalty, then this offering from Scott does tick a lot of the boxes when it comes to performance.

We found Cervelo's R5 to be an excellent all-rounder with its aero touches providing the benefits on the flat, while its stiffness makes it a flattering companion on the climbs. It's also supremely comfortable too making it ideal for those longer rides when you have the time.

The Sram Force AXS eTap build we reviewed tipped the scales at 7.3kg which is half a kilo over the UCI's weight limit, but it's based around a feather light frame of 703g (claimed) for a size 56cm, that's 103g lighter than the previous version, so there is definitely some scope there for a very light bike indeed.

Anne-Marie found the geometry numbers to be a little different to those used by many other manufacturers for a bike of this type and size. Most notably the slightly slacker seat tube angle, and you get quite a short reach measurement too, but she found that as a complete package everything worked very well which is what gives the R5 those excellent all-rounder qualities.

Weighing 7.2kg and offering supreme comfort, the Defy should be high on your wishlist if comfort over long distances is your priority. There are much less expensive build options of course, if your budget doesn't stretch to £11,500!

Our reviewer praised the lovely amount of flex from the D-Fuse technology, and the chunky 32mm tubeless tyres increasing comfort further. It's a very smooth ride, and the tweaked geometry offering a slightly shorter head tube than the previous version makes the Defy a touch racier. With full internal cable routing and semi-aero wheels, there's no need to swerve the Defy if you want to go fast. 

While expensive even for a superbike, the Defy does everything it says it will do and is surprisingly lively for an endurance bike. You'll get most of the benefits of this hero model further down the range, too. 

This Team model uses the fifth generation of the Scultura frameset, which shares the geometry of Merida's aero race bike, the Reacto and shares some of the wind cheating design.

It's ridden at the top level by the Bahrain Victorious ProTour team, which means that there is a huge amount of stiffness throughout for coping with a professional's explosive leg power, while the handling is fast, and very precise indeed.

Although we did find the top half of the frame and the fork to give a very comfortable ride too, which wiped out any road buzz without muting the feedback.

At 7.1kg this build feels impressively quick when accelerating, or maintaining speed on the flat, and for a bike with decent amounts of aero styling it climbs well too. It also looks the business with its smooth lines thanks to full internal cable and hose routing, plus the integrated seatpost clamp.

Chapter2's Toa frameset isn't necessarily superlight on paper, but that doesn't stop it from being built up into a lightweight race bike that'll take 32mm tyres with ease.

The model we reviewed was built up with a Dura Ace mechanical groupset, deep section wheels and various carbon fibre pieces of finishing kit which weighed in at 7.4kg.

As for the ride, well it really can't be faulted with sweet handling and geometry that puts you into an aggressive position for riding hard against opponents or just on your own.

Comfort is great too, for such a stiff bike.

Chapter2 offer the Toa as a frameset which includes the seatpost and integrated cockpit, plus the paint colours are made in small runs giving a bit of a custom finish to each batch.   

Okay, so it's not technically a road bike, but the S-Works Crux is described as "the lightest gravel bike in the world" and it also works very well on the road too.

The geometry allows for a low-slung position for speed work, while a slightly longer wheelbase than most road bikes gives it that extra stability off-road. In his review Liam said that he was very impressed with the handling meaning that the Crux copes well with technical descents and it's a prolific climber too. 

It's definitely not cheap at its current price of £11,700, but you are getting some very top end kit with a Sram RED eTap groupset, Roval Terra CLX wheels, and S-Works finishing kit throughout. There are also less expensive models in the range. 

Basically, if you want to ride as fast off of the road as you do on it, then the S-Works Crux should be on your shopping list.

While not the lightest bike available at 7.4kg, Ridley's Falcn RS has aero wheels and Shimano's Ultegra Di2 groupset, so could easily go under 7kg with some lighter components and finishing kit. 

The Falcn is very much an all-rounder, with a fast and light frameset that is capable of taking up to 34mm tyres. Our reviewer said the frame offered an involving and responsive ride, and bang in the middle of fast and comfortable. 

The Falcn looks modern with very neat integration, and is well worthy of your consideration if you want a do-it-all road bike.