Best lightweight bikes 2020: a buyer’s guide to climber’s bikes

Looking for the best lightweight, hill-flattening, mountain-conquering machine? We’ve tested the best lightest and fastest climbing road bikes on the market.

A lightweight bike will help you sail up the climbs and accelerate out of the bends. The desire to save weight spans the generations, but things have moved on now from drilling holes in your steel frame. Carbon frames, wheels, and much else besides have made bikes both light and strong – although certainly not cheap.

You might be wondering what’s the point in a lightweight bike these days—isn’t aero all we should care about? It’s only (steep) uphill efforts where a lightweight bike is faster, but that’s ignoring the time lost descending the other side.

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>>>Watch: Why you should always choose an aero bike over lightweight

While it’s true that a lightweight bike may not be as fast as an aero bike in the majority of circumstances, that somewhat misses the point. Lightweight bikes, quite simply, are fun. The instant response to the slightest acceleration, the sprightliness as you twist up the hills, makes for an, arguably, more engaging and enjoyable ride.

Who can really feel the difference between trundling along at an average of 32kph versus 31kph? Whereas how responsive a bike is to your slightest input is something that you do directly feel. Aero may be a lot of things, but when did you last hear a TT bike described as “exciting”?

If you’re just going out for a spin with a few friends, the chances are you won’t be travelling at the speeds which make unmitigated aero-optimisation worthwhile. Lightweight bikes still have their place, plus many of them have recently been tweaked to better cheat the wind, anyway.

>>>Read: At what point does aero become more significant than weight?

Best lightweight bikes

This guide includes links to some products. With each product is a ‘Buy Now’ or ‘Best Deal’ link. If you click on this then we may receive a small amount of money from the retailer when you purchase the item. This doesn’t affect the amount you pay.

Giant TCR Advanced SL 0 Disc

Best Lightweight Climber’s Bikes

Score: 8/10

Weight: 6.6kg in size M/L (verified)

Price as reviewed: £9,499

As with many lightweight bikes these days, there is more than a passing nod to aerodynamics. The tube shapes have been redesigned to slip through the air and it came with 42mm deep rims. But in spite of this, it still manages to dip below the UCI weight limit.

We found the bike fun and agile to ride and it is a bike that just makes you want to push yourself on every road. The ride is admittedly somewhat harsh and the integrated seat post needs to be cut down to your size – so definitely get a good idea of your bike position before riding this bike.

Read more: Giant TCR Advanced SL 0 Disc review

Buy now: Giant TCR Advanced SL 0 at Rutland Cycling for £8,998.99

Specialized S-Works Tarmac SL7

Best Lightweight Climber’s Bikes

Score: 9/10

Weight: 6.6kg in size 52 (verified)

Price as reviewed: £10,500

Another lightweight bike that has received an aero makeover. It’s not just the frame that cheats the wind; the wheels are 51/60mm deep, which is impressive for so light a build. The cable routing is particularly tidy, remaining out of sight until the last possible moment, before popping out for the callipers and derailleurs.

The combination of aerodynamics and lightweight mean this is a bike which wants to go fast everywhere. It holds its speed on the flat and, when the road tilts up, it responds immediately to the slightest acceleration. However, the ride is noticeably harsher than its heavier little brother, the SL6.

Read more: Specialized S-Works Tarmac SL7 review

Buy now: Specialized S-Works Tarmac SL7 at Tredz for £10,500

BMC Teammachine SLR 01

Best Lightweight Climber’s Bikes

Score: 8/10

Weight: 6.6kg in size 49 (verified)

Price as reviewed: £10,250

Lightweight, responsive and handles well. The aerodynamic optimisation has even extended to the bottle cages in this bike, but the integrated handlebars make cockpit adjustments a bit more of a headache.

The ride quality was perfectly acceptable on good roads, but the chatter from bad ones felt as though it was being accentuated. There is room for tyres up to 30mm wide, so there is scope for improving this with wider rubber.

Read more: BMC Teammachine SLR 01 review

Buy now: BMC Teammachine SLR 01 at Sigma Sports for £10,499

Canyon Ultimate CF Evo Disc 10.0 LTD

Best Lightweight Climber’s Bikes

Score: 9/10

Weight: 5.98kg in size XS (verified)

Price as reviewed: £7,449

Full disclosure: the sub six kilo weight was with a carbon Selle Italia SLR C59 saddle fitted and without pedals and bottle cages. But even in a more realistic set-up, it still comes in well under the 6.8kg UCI weight limit.

Impressively, Canyon have managed to combine lightweight and stiffness with a relatively comfortable ride, with the one-piece bar absorbing a good amount of the road chatter. What stopped this bike from receiving a full 10/10 was the handling. The simple fact is, it just isn’t as sharp as other bikes around this level.

Read more: Canyon Ultimate CF Evo Disc 10.0 LTD review

Buy now: Canyon Ultimate CFR Disc at Canyon for £8,499

Cervélo R5 Disc

Best Lightweight Climber’s Bikes

Score: 8/10

Weight: 6.9kg in size 51 (verified)

Price as reviewed: £8,399

Stiffness has not been sacrificed in the pursuit of lightness. The downtube, seatpost, and chainstays have all been stiffened up at the oversized bottom bracket, making the response to your every pedal stroke instantaneous.

The distribution of the little weight it does have is not optimal, however, with the front end feeling rather light. It is also missing some of the aero optimisation displayed by its competitors.The high seatstays a point in case.

Read more: Cervélo R5 Disc review

Buy now: Cervélo R5 Red eTap AXS at Sigma Sports for £7,249

Scott Addict RC Pro

Best Lightweight Climber’s Bikes

Score: 9/10

Weight: 6.9kg in size large (verified)

Price as reviewed: £6,299

For an ultra-light bike, the Scott Addict managed to deliver an exceptionally smooth ride. A large element of this is probably due to the 28mm tyres it comes with. Given the wider rubber, and respectably deep 35mm rims, its 6.9kg weight in a size large is all the more impressive.

However, the Schwalbe Pro One tyres did prove themselves to be somewhat puncture prone. Although, if they were run in their tubeless guise this may not have been an issue.

Read more: Scott Addict RC Pro

Buy now: Scott Addict RC Pro at Rutland Cycling for £6,298.99

Pinarello Dogma F12

Best Lightweight Climber’s Bikes

Score: 9/10

Weight: 6.7kg in size 54 (verified)

Price as reviewed: £10,500

Particularly aero and lightweight, this is a thoroughbred racing machine, as has been proven across multiple Grand Tours. This most definitely comes at a cost though, with certain builds reaching up to £12,000.

But this bike is not without compromises. The extreme stiffness translates into a somewhat harsh ride, while the P-Zero tyres our test bike was spec’d with proved themselves to be a little on the fragile side.

Read more: Pinarello Dogma F12 review

Buy now: Pinarello Dogma F12 Dura-Ace Di2 at Sigma Sports for £10,000

Bianchi Specialissima

Best Lightweight Climber’s Bikes

Score: 9/10

Weight: 6.6kg (verified)

Price as reviewed: £8,750

Retaining the classic look of a lightweight bike, the Specialissima comes with rims brakes and seatstays that meet the top tube. That isn’t to say there aren’t modern touches: the fork integrates cleanly with the frame and the bottom bracket is substantially oversized to provide stiffness.

It isn’t just the climbs this bike excels on, the aggressive geometry makes it a nimble descender, encouraging you to really chuck it into the turns.

Read more: Bianchi Specialissima review

Buy now: Bianchi Specialissima at Tredz for £4,800