At road.cc every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.
Good scores are more common than bad, because fortunately good products are more common than bad.
The Gaerne Carbon G.STL road shoes are powerfully stiff-soled shoes with excellent heel retention – the latter thanks to a narrow, rigid cup combined with anti-slip fabric. The Boa dial gives plenty of incremental adjustability, done up sprint tight I found they could pinch. For all other efforts, though, these are comfortable and secure.
Made in Italy, the G.STL is Gaerne's new top-end road shoe, taking top spot from the G_Stilo. The G.STL uses Gaerne's EPS Carbon 12.0 Sole, which gets the full 12 out of 12 on its stiffness index.
This translates to an ultra-stiff platform. As you bury yourself, it feels like no watt is wasted – there's no detectable flex. It also has a very slim design that brings your foot closer to the pedal for a more efficient stroke.
Cleat position options have been increased by 9mm over the previous sole. I found this range easily enabled me to set up my preferred position. An alignment scale is also included, which is useful.
There's a dainty anti-slip insert beneath the toe box, while the heel is replaceable to boost longevity. Both of these are small, but work well.
The supple, thin upper has tiny laser perforations for ventilation across the whole foot. This works with four reasonably-sized vents in the sole; three in front of the cleat, and one just behind. While the test period was not remotely warm, during intense indoor sessions my feet remained a comfortable temperature and didn't overheat.
The traditional tongue design has been improved by using variable thicknesses to provide comfort where needed and perforation for breathability. This seamless construction has a low-profile soft layer that provides just the right balance between comfort and locked-down security.
At the top end of the tongue there are two cutouts which split the tongue into three parts. This allows the tongue to bend comfortably with the foot – there's no pinching here at all.
The updated Anatomic Heel Cup is rigid and narrow for a close and secure hold. This works alongside an internal anti-slip fabric which is smooth as you slip your foot inside the shoe, but has a rough texture when pulling back up. This is designed to prevent heel lift, and it does so very effectively. Kicking the pedals in all-out efforts, I never noticed my heel slipping one bit.
The incremental adjustability of the dual Boa Li2 dials really allows you to get the tension just right. These can be micro-tightened and loosened, so you can finetune either direction. The Boa laces weave between eight fixing points (four for the upper, four for the lower) to evenly distribute tension across the foot.
The upper dial works with a wide strap for spreading pressure across a large area, and it does this very well. The other dial deals with the mid to low foot. Tightened up for endurance rides all the way to threshold efforts I was held comfortably and securely, but really cranking these up tight for VO2 efforts and sprints, the G.STLs pinched the edge of my feet at my outermost metatarsophalangeal (MTP) joint.
When loosening back down to a fit that felt comfortable, my forefoot didn't feel quite as planted as I'd like in short, snappy and intense efforts.
Quite often white kicks can be a pain to keep glistening clean, but these proved easier than most to keep smart. This is thanks to the small perforations that don't trap dirt so easily, and the absence of mesh sections that discolour and can't be wiped down. They are also available in matt iridium and matt black, and all have a reflective 'G' logo on the rear for a touch of visibility.
I found the G.STLs twin-Boas made these a lot easier and quicker to take off and put on than some, such as Specialized's Ares sock design or Sidi's Shot 2 Tecno-3 Push Flex closure. The G.STLs are go-to shoes for training, as well as the all-important race days – they combine top performance with practicality.
At 592 grams (EU 43) they aren't particularly light for a top-end shoe. The recently-released Specialized S-Works Ares are 564g in the same size. That said, Sidi's Shot 2s are a chunk heavier at 616g (again in EU 43).
At £379.90 the price is high, but it's ballpark against the serious competition. Specialized's S-Works Ares shoes and Sidi's Shot 2s are both £375, for instance, while Lake's CX403 CFCs are £425 – thought they're also custom-mouldable.
These all make Shimano's S-Phyre RC9 SPD-SLs look a bargain at £319, especially as Liam found they deliver so well on stiffness, heel retention and comfort.
The G.STLs are great fun for smashing it on training rides and race days. They're very comfortable unless you really crank up the lower Boa for sprinting, but it's really not so bad as it's just for a short period – and the Boa can be micro-loosened afterwards. They're easy to wipe down and slip on/off, too, so very practical for everyday riding – assuming you're happy using such expensive shoes so regularly.
Excellent stiffness matched with practical design that works for both training and racing
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road.cc test report
Make and model: Gaerne Carbon G.STL road shoes
Size tested: 43
Tell us what the product is for
Gaerne says: "GAERNE EPS LIGHTWEIGHT FULL CARBON SOLE 12.0 Ultra light and ultra thin, the optimised carbon fiber weave ensures every watt of power is transferred to the pedals. The stability of the foot is increased thanks to the shape of the sole in the plantar arch area. Four air vents guarantee ventilation inside the shoe. The sole has an anti-slip insert in the toe and an interchangeable pad in the rear. Cleat position options have been increased by 9mm compared to the previous sole. An alignment scale printed on the sole allows you to memorize the position of the cleat. Outstanding stiffness index of 12."
Tell us some more about the technical aspects of the product?
UK importer Hotlines lists:
One-Piece Microfibre perforated upper with anti-abrasion zones
Fit Tongue 1.0
Anatomic Heel Cup 1.0
Tarsal Support System 1.0
Boa Li2 Twin-Dial adjustment - InFit closure system with 8 fixing zones
EPS Comfort insole
Integrated anti-slip heel-cup
3-bolt cleat compatible (cleats not supplied)
Weight: 274g (Size 43)"
Very well made.
So far, so good. The heel is also replaceable.
These are true to size. I'm usually EU 43 and these are just right.
Decent compared to the top-end competition, but the Specialized S-Works Ares shoes are 28 grams lighter.
Perfectly comfy, bar some pinching at the edges (at my outermost MTP joint) when tightened up for sprints.
How easy is the product to care for? How did it respond to being washed?
With no mesh sections, these are easy to wipe down and keep white.
Tell us how the product performed overall when used for its designed purpose
Excellent for long rides up to pacier threshold efforts, but I suffered some slight pinching with them tightened for all-out sprints.
Tell us what you particularly liked about the product
Stiff sole, easy to clean.
Tell us what you particularly disliked about the product
Slight pinching when tightened hard for sprints.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
They're at the upper end. Shimano's S-Phyre RC9 (RC902) SPD-SL shoes are cheaper at £319, but Specialized's S-Works Ares and Sidi's Shot 2s aren't too far off at £375.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes, for both training and racing
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
The G.STLs are very stiff – perfect for race days – but comfortable as well as practical for longer training rides. They're also easy to wipe down. Those who really like to cinch their shoes super-tight for sprinting may suffer some pinching along the outer edges, but nevertheless they're very good.
About the tester
I usually ride: Road bike My best bike is:
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: road racing, cyclo cross, commuting, touring, club rides, sportives, general fitness riding, Gravel riding, indoor turbo and rollers, track
Anna has been hooked on bikes ever since her youthful beginnings at Hillingdon Cycle Circuit. As an avid road and track racer, she reached the heady heights of a ProCyclingStats profile before leaving for university. Having now completed an MA in Multimedia Journalism, she’s hoping to add some (more successful) results. Although her greatest wish is for the broader acceptance of wearing funky cycling socks over the top of leg warmers.