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Best lightweight bikes: our pick of gravity-defying climbing bikes

Best lightweight bikes
(Image credit: Colin Levitch)

In the past, finding the best lightweight bike has been the sole requirement for a road cyclist when buying a new bike; saving weight was a racer's primary concern in the pursuit of speed. Such was the obsession that in cult book The Rider, Tim Krabbé recounts being told by another cyclist that, "Anquetil always moved his water bottle to his back pocket during climbs, so his bike would be lighter."

Conversely, the contemporary fashion for aerodynamics might, at first glance, make lightweight bikes seem like a bit of an anachronism, but there are actually still a number of sound reasons why you should consider one as your next bike. 

Today, many lightweight bikes still feature prominently in our guide to the best road bikes, but with the UCI steadfast on a minimum weight limit of 6.8kg, advancements in design have looked towards improving aerodynamics and ride quality without increasing weight, to make the best lightweight bikes more enjoyable to ride, easier to own and faster over flatter terrain.

Below, we run through our pick of the best lightweight bikes available today, followed by a short guide on what to look for when choosing

Best lightweight bikes

Cannondale SuperSix Evo Hi-Mod Dura-Ace Di2 Disc

(Image credit: Cannondale)

Cannondale SuperSix Evo Hi-Mod Dura-Ace Di2 Disc

Progressive aero update to one of the most acclaimed lightweight bikes

Price: £10,500.00 | Weight: Unpublished | Brake: Disc | Frame: Carbon | Sizes: 51cm-60cm

Tyre clearance
Women’s specific builds available 
No power meter

With its renowned blend of low weight and enormous stiffness, the Cannondale SuperSix has long been considered one of the best road bikes for climbing, but its round-tubed design was admittedly getting a little long in the tooth.

The latest SuperSix brought with it a complete design overhaul, with truncated aerofoil tubing, a sleek integrated cockpit and system designed wheels. The SuperSix maintains the glorious pedalling efficiency, low weight and razor-sharp handling, but dropped seat stays increase comfort and hydraulic disc brakes bring improved braking control and tyre clearance.

Now arguably more of an all-rounder than just a pure climbing bike, the Cannondale SuperSix does sit a few hundred grams over the UCI weight limit, but the aerodynamic gains will likely offset this on less steep climbs.

Those who prefer Shimano get the EF Education team colourway with its wavey pink and blue checkered motif however Cannondale don't appear to spec the Dura-Ace DI2 bike with a power meter. SRAM fans are in luck though as the Red eTap AXS equipped SuperSix EVO Hi-MOD does include a power meter.

Cannondale SuperSix Evo review

Giant TCR Advanced SL 0 2021

(Image credit: Josh Croxton)

Giant TCR Advanced SL 0

The Giant TCR Advanced SL 0 is incredibly light, stunningly stiff and it holds flatland speed well, it's an out and out super bike

Price: £9,499 / $11,000 / AU$13,999 / €10,199 | Weight: 6.96kg | Brake: Disc | Frame: Carbon | Sizes: S-XL

Weight (sub 7kg, size large)
It holds speed over flat and rolling ground well
Power transfer is similar to a dedicated aero bike
Handling confidence takes time to build
The integrated seatpost makes flying with the TCR difficult, but not impossible
No Shimano builds available at Advanced SL level

The TCR Advanced SL 0 is a world-class road race bike. All the metrics and the riding experience suggest it has managed to bring itself back in line with - if not ahead of - the competition. 

With the price at £9,499 / $11,000 / AU$13,999 / €10,199, the TCR Advanced SL 0 is in the same ballpark as the S-Works Tarmac, Cannondale SuperSix EVO and the Trek Emonda. 

The TCR Advanced SL 0 misses out on a perfect score due to a couple of things. The negatives of the ISP outweigh the positives and the lack of a Dura-Ace build is something that will put many riders off. 

All things told, if you're forever chasing the final watt of energy, there will always be a new bike that claims to be faster, lighter, better. If you're looking for a world-class bike that brilliantly blends weight, aerodynamics and efficiency, the Giant TCR is a bike you should consider every single time. 

Giant TCR Advanced SL 0 review

Specialized S-Works Tarmac SL7

(Image credit: Specialized)

Specialized S-Works Tarmac SL7

Hugely popular, WorldTour race winning lightweight bike, now aerodynamically optimised

Price: £11,500 | Weight: 6.89kg | Brake: Disc | Frame: Carbon | Sizes: 44cm-61cm

Grand Tour winning pedigree
Aerodynamics and power transfer on par with Venge
Same weight as outgoing SL6
Harsher ride than SL6
Huge price

The latest version of Specialized hugely popular Tarmac retains the fantastic efficiency and handling of the SL6 but now has enough aerodynamic clout that it's killed off Specialized's Venge aero bike.

In actual fact, the aerodynamic differences still swing in favour of the Venge - to the tune of 2.5 watts. However, with all metrics factored in, such as rider freshness, handling, acceleration and, of course, weight, the Tarmac was the victor on all of Specialized's course profile simulations. 

It's pricey, but you do arguably get a lot for your money. Specialized specs its own components and wheels, but in every case these arguably rival or surpass offerings from dedicated component brands. You get a set of Specialized's S-Works Power cranks, a carbon-railed S-Works Power saddle, S-Works Aerofly II handlebars and the Roval Rapid CLX 60 Disc carbon wheels with CeramicSpeed bearings and Specialized Turbo Cotton tyres.

Specialized makes a big deal about the fact that each frame and fork size in the range is built with their Rider-First Engineering design, which means each size gets specific carbon layups and fork tapers, so that ride quality is maintained across the board.

Specialized S-Works Tarmac SL7 review

scott addict rc ultimate bike

(Image credit: Scott Bikes)

Scott Addict RC Ultimate

Addicted to the climbs and the sprints

Price: £11,889.00 | Weight: 6.9kg | Brake: Disc | Frame: Carbon | Sizes: 47cm-61cm

Fully integrated cockpit
Aero tube shapes
Torx bolts

The Addict RC Ultimate unsurprisingly sits at the top of Scott's line up. The frameset, which will be ridden by Roman Bardet for Team DSM, is built from Scott's HMX SL Carbon and forms aerofoil tube shapes for improved aerodynamics. Following the aero trend, Scott has also completely hidden all cables within a Syncros Combo Creston iC cockpit. 

The Ulitmate spec model comes with a pick of the best road bike components and features a SRAM RED eTap AXS Disc (including power meter), Zipp 303 Firecrest Disc wheels and finished in Syncros carbon kit. If the heavy price tag of the ultimate is off-putting, Scott offers the same frame in a range of build specs down to Shimano 105 to cater for more reasonable budgets too.

Scott Addict RC 15 review

Bianchi Specialissima CV Ultegra

(Image credit: Bianchi )

Bianchi Specialissima CV Ultegra

Bianchi's range-topping lightweight frameset specced to a budget

Price: £4,499.00 | Weight: Unpublished | Brake: Disc | Frame: Carbon | Sizes: 47cm-61cm

Lightweight 750g frame
Now with disc brakes
Lower spec than others here
Frame has obvious aero consideration

While more premium models exist in the Bianchi range, we see this Specialissima as a great halfway step into the realms of the top-of-the-range lightweight bikes. Bianchi's big update is that the Specialissima now has disc brakes and, assuming Bianchi has calibrated its scales, managed to knock 30g off the overall frame weight.

With the premium Specialissima frameset hitting the shelves at £4,499.00, this model completes the build with some aluminium Fulcrum wheels and a full Ultegra groupset for a shade over £1,000 more. 

Alternatively, if you're looking to spend big, the Dura-Ace Di2 disc version can be had with Vision SC40 carbon wheels at £10,499. 

BMC Teammachine SLR01 Disc Two

(Image credit: BMC)

BMC Teammachine SLR01 Disc Two

Forward thinking bike design that seemed to inspire almost every other brand

Price: £9,499.00 | Weight: 6.8kg | Brake: Disc | Frame: Carbon | Sizes: 47-61cm

Stiffness & handling
BMC Teammachine SLR01 Disc Two
No power meter

Dropping the seat stays for improved comfort and aerodynamics was a 2019 bike-design must-have, but the BMC commitment to progressive bicycle design is such that they debuted this feature back in 2010 on the Teammachine.

The combination of massive pedalling stiffness from the oversized down tube and bottom bracket area, combined with the comfort gained from thin, dropped seat stays, made this design a winner from the start. Cadel Evans promptly rode to victory in the Tour de France only a year later, in 2011, and it continues to be the bike of choice for riders of both Qhubeka Assos and AG2R Citroen today, thanks to its blend of efficiency, comfort and perfectly balanced handling.

With the addition of hydraulic disc brakes, a semi-integrated cockpit system (that still retains adjustability for both fit and maintenance) and updated cable management, the Teammachine is more evolution than revolution, but this just shows how advanced the original design was at the time. There's little about this bike that looks out of date.

Our only major concern when reviewing was the lack of power meter for such a high price. 

Trek Emonda SLR 9

(Image credit: Colin Levitch)

Trek Emonda SLR

A bike that's just as quick going down hills as it is at going up them

Price: £9,700 | Weight: 6.86kg | Brake: Disc | Frame: Carbon | Sizes: 47cm-62cm

Customisation options
Design not as evolutionary as rivals

It should come as no surprise that Trek focused on improving the aerodynamics of the new Emonda. Trek is not alone in this with Giant, Scott, Specialized and Focus (among others) also going this route, addressing the fact that aerodynamics come into play, even when you’re not travelling 40kph on flat ground. The new frame sees truncated aerofoils on the fork legs, downtube, seat tube and seat stays which the brand says saves 183g of drag over the previous model. Interestingly the no-cut integrated seat mast is round, and so is the cap, which Trek says helps to retain compliance. 

While 183g of drag is probably an abstract figure to anyone that doesn’t have an aerodynamicist within arms reach, Trek has modelled how much time a rider would save up various famous climbs around the world riding at 350-watts on the 2018 Emonda vs the 2021 Emonda. The new bike saves 15-seconds on Alpe D'Huez, 11-seconds on the Angliru, 21-seconds up the Stelvio, 80-seconds up the Taiwan KOM Challenge and 4-seconds up Willunga Hill. 

For the latest edition of the Emonda, Trek as added a few new colour schemes to its Project One program ICON, KOM and Ultimate. Our test sample is the latter, which allows you full creative license over Trek’s colour palettes as well as tailoring every component. The yellow to pink fade is definitely Trek flexing its proverbial painting muscles, and the bike is anything but subtle.

Factor O2 VAM Disc road bike

(Image credit: Aaron Borrill)

Factor O2 VAM Disc

An out-the-box hill climb weapon

Price: £8,999 | Weight: 6.78kg (actual) | Brake: Disc, rim | Frame: Carbon | Sizes: 46-61

Exquisite aesthetics
Stiff and light chassis
Super-fast and reactive on the climbs
Predictable handling
Superb value for money at this spec-level
Ride quality can be quite hard at times

The Factor O2 VAM Disc can easily hold its own against the segment's best road bikes. It's unquestionably light, superbly efficient on the flats and descends with predictability, sure-footedness and poise. Sure, there are faster bikes out there but unless you're riding at the highest level of the sport or testing it back-to-back against its rivals in a controlled environment those nuances are imperceptible to us mere mortals. 

The O2 VAM doesn't profess to be a jack of all trades. It's a master of situations where the road angle tilts upwards and gravity comes into the equation. This is a place where it's at its happiest.

As far as lightweight climbing bikes go, the Factor O2 VAM represents the zenith of the genre and doesn't pretend to be anything other than what it says on the tin. If it's pliancy and outright speed you're after then you're in the wrong place - go find an aero road bike instead.

Factor O2 VAM Disc review

Canyon Ultimate CF SLX 9 Disc Di2

(Image credit: Canyon)

Canyon Ultimate CF SLX Disc 9.0

Great value, super-efficient lightweight bike with top-of-the-line spec

Price: £7,899.00 | Weight: 6.92kg | Brake: Disc | Frame: Carbon | Sizes: XXS-XXL

Aerodynamic cockpit
Wide range of sizes
Women's models available 
Can only be purchased online

With Canyon's direct-to-consumer approach, it's hard to argue the value for money aspect of the German behemoth's range. While this particular model is still a considerable investment at £7,899, the 2021 Ultimate CF SLX range starts at £5,649 and the Ultimate CF SL can be had for as little as £2,399.00.

Women's versions are available, and finishing kit varies between the two genders - such as the VCLS post being included on the equivalent women's bike. Canyon claims the women's frameset is lighter and more aerodynamic than the men's version, but then it contradicts this with claimed weights of 7.07kg (women's) to 6.92kg (men's) for the ETAP disc version.

The Dura-Ace version sees an integrated cockpit, albeit with cables on show, DT Swiss ARC 1100 Dicut wheels paired with Schwalbe Pro One Evo 25mm tyres, and a Selle Italia SLR Boost Superflow Kit Carbonio saddle. 

Cervelo R5 Red eTap AXS

(Image credit: Cervelo)

Cervelo R5 Red eTap AXS

A no-compromise lightweight bike that hides its performance credentials behind classic looks

Price: £9,919.00 | Weight: Unpublished | Brake: Disc | Frame: Carbon | Sizes: XS-XXL

Classic looks
User friendliness
Design arguably getting dated

The R5 is the climbing bike at the disposal of Team Jumbo–Visma, the Cervelo R5 is a bit of a wolf in sheep’s clothing. It would be easy to look at the traditional frame shape and assume it’s a vestige of a by-gone era (especially compared to wild aero design of the Cervelo S5 Disc), but you’d be far from the truth.

The Cervelo R5 is built from Cervelo's Squoval Max aerodynamic tubing, tuned to balance phenomenal levels of stiffness with low weight, whilst a stable yet racy geometry and hydraulic disc brakes offer confidence-inspiring handling. It also has clearance for 30mm tyres, so if you want more volume for grip and comfort on rough roads, this bike can handle it.

Up front, Cervelo specs its own carbon stem and handlebars. There are nods to aerodynamics here, but Cervelo hasn't yet gone down the route of full S5-style cockpit integration with the R5. 

This invariably means a small aerodynamic penalty, but it does also mean you can easily change the stem length or handlebar width to suit your personal fit requirements – something that might not be possible with a fully integrated system.

Wilier Zero SLR

(Image credit: Wilier)

Wilier Zero SLR Disc Dura-Ace Di2

Thoroughly modern lightweight bike from one of the oldest racing bike manufacturers in the world

Price: €11,300 | Weight: 6.8kg | Brake: Disc | Frame: Carbon | Sizes: XS-XXL

Brand heritage
No women’s builds available

Despite their illustrious histories, Italian manufacturers are generally not renowned for being on the cutting edge of bicycle design. We tend to think of Italian racing bikes as beautiful, classic, perhaps even old fashioned – but the reality is that, with Wilier at least, this couldn't be further from the truth.

The Zero SLR Disc is the lightweight bike from Wilier. Borrowing design cues from their Cento10 Pro aero bike, it's a thoroughly modern lightweight bike. It ticks all the boxes; a super lightweight carbon frame with truncated aerofoil tube shapes, integrated handlebars with fully hidden cables, hydraulic disc brakes, carbon wheels and clearance for 28mm tyres.

Its tried and tested geometry, and stiff frame and fork mean handling is great, and its clean lines and complete cable integration make it a real looker. Wilier is kind enough to offer some very nice paint jobs as well – matte black with white detailing, matte velvet red and a glossy admiral blue. The matte black frameset is slightly lighter, but go for the red or blue for that essential touch of Italian flair.

There's no denying that this is a pretty expensive bike – Wilier retains that classic Italian bike characteristic – but you're buying into a European brand with over 100 years of experience in making bikes, and all of the racing heritage that comes with that.

As of yet, there doesn't appear to be any women's specific versions available, but, hopefully, that’s something Wilier will offer in the near future.

Best lightweight bikes explained

1. The 6.8kg UCI weight limit

With the UCI weight limit seemingly stuck at 6.8kg, 'lightweight' has been largely defined at that point, and brands have been able to focus their attention on improving other areas of the bike, instead of simply chasing grams in a race to the bottom (although, naturally, that is still a thing). 

Where aero bikes often have to make compromises on things ride quality, fit and user-friendliness in pursuit of all-out speed, lightweight road bikes have tended to become the all-rounders of road cycling, with development focused more on these important, but often undervalued characteristics.

Such are the improvements in these areas that many WorldTour pros still choose to ride lightweight bikes over their sponsors' aero-bike offerings, despite the apparent penalty in aerodynamic efficiency.

2. When does a lightweight bike make the difference?

The data tells us that aerodynamic bikes are faster on flat and rolling courses, but let's be honest – the hills are still where it really counts. The important Strava segments are, generally, not boring sections of flat or rolling road, they’re hills, and, on the proper hills, lower weight still beats aerodynamics.

One relatively recent development is the appearance of disc brakes on the best lightweight bikes. Rim brakes have long been favoured because of the difference in weight, but the gap has narrowed considerably, and it's worth considering that what goes up must also come down. 

You might appreciate the improved power, consistency and modulation of hydraulic disc brakes when you're coming back down that 20 per cent hill, with your heart rate pushing off the scale after a full-gas KOM attempt, and it's largely accepted that disc brakes offer better braking performance, especially when the conditions take a turn for the worse.

3. N+1

Perhaps more crucially, lightweight bikes still retain the power to impress your friends or family members, because weight is tangible. Show them an incredibly expensive aero bike and the first thing they'll do is pick it up and complain that, "It's quite heavy… How much did you say this cost?"

By the time you've started explaining that "over a typical 40km rolling course, performance modelling shows that this bike is 45 seconds faster at 50kph than an equivalent lightweight bike…" they'll likely have lost interest and wandered off, thinking that you got royally ripped off.

A lightweight bike provides an obvious tangible difference, and, sometimes, that provides a greater psychological benefit than the few intangible seconds offered by manufacturers. 

4. Carbon copies 

Unsurprisingly, carbon fibre dominates the scene for lightweight road bikes. Its unique, tunable characteristics make it the perfect material for making light and stiff bikes that excel when pointed uphill. The downside is that these lightweight frames and components tend to come at an exorbitant cost.

As the great Keith Bontrager once said: "Strong, light, cheap. Pick two." That said, If the UCI limit is what you're looking at, you don't necessarily need to buy the top-of-the-range model these days, which will often actually be lighter than the UCI's minimum weight limit. Some brands are even able to offer builds with Shimano Ultegra that can still hit the 6.8kg benchmark; just don't expect them to be particularly cheap. 

Of course, bikes are readily discounted, so it's worth taking a look at our roundup of the best road bike deals to find the best bike-to-price ratio.

What do you think is the best UCI legal lightweight bike currently on the market? Are lightweight bikes even still relevant in the era of 'aero is everything'? Let us know what you think in the comments below.