Giant Defy Advanced SL 1

The Giant Defy Advanced SL 1 is light, efficient and impressively comfortable. Everything an endurance-cum-allroad bike needs to be. In fact, I’d say it is one of the best all-round packages available for this genre of bikes, especially if carbon fibre is a must.

If you’re interested in the Defy Advanced SL 1, you might want to check out others in our guide to the best endurance road bikes.

Giant Defy Advanced SL 1: Ride

The majority of you will already know this, but in case you don’t I’ll give a little run-down on where the Defy sits in Giant’s road line-up. For flat days the Propel is the aero race machine, while the TCR is its lightweight, aggressive race bike for all kinds of topography. The Defy shares much of the DNA of the TCR but has a slightly more relaxed nature; the geometry isn’t quite as aggressive, it’ll run wider tyres, and it has more compliance in the frameset.

That doesn’t mean the Defy is a soft option when it comes to performance, and to be honest the differences between it and the TCR aren’t massive.

I own a TCR. It’s not one of the bling options, but the 2022 Advanced 2 model I bought last year as new/old stock, and I love the way it rides (as did Mat when he reviewed the TCR Advanced Pro 0 AXS last year). It’s had some upgrades, mind, running the latest SRAM Rival AXS groupset and a set of Hunt’s new Aerodynamicist wheels, so from a spec point of view it’s similar enough to provide a good comparison with the Defy.

The TCR is nimbler, the steering feels more direct, and it has a lower front end for an aggressive aero position, but when riding the two back-to-back I was massively impressed with just how close the Defy is in terms of performance. Especially for someone like me who doesn’t race, but still prioritises speed and quick steering over comfort.

One of the key factors is frame stiffness. The Defy Advanced SL feels incredibly tight around the bottom bracket and head tube areas, so when you add that to the 7.4kg weight it feels lively when you push the pedals whether under acceleration or on the climbs.

I’ll go into the full geometry numbers in a bit, but let’s just say the Defy has a steepish head angle for an endurance bike, which means that it handles well through the corners at speed. A slightly larger fork rake than a race bike and the lengthier wheelbase combine to give an overall feel of stability.

It’s not as razor sharp as a race bike in the tighter, technical sections but it is very close, and that stable nature means the Defy doesn’t present any twitchiness at the front wheel when asking it to change direction quickly, and it isn’t unsettled by rough road surfaces either.

Giant says that the Defy’s frame and fork have been engineered for endurance road riding, focusing on compliance in the carbon layup, helped by the addition of its D-Fuse components to bring extra comfort at your contact points.

It all adds up to a very comfortable ride, front to back, but it’s been done in such a way that it hasn’t compromised a feeling of engagement between rider and bike. The Defy is an involving bike to ride, giving loads of feedback of exactly what the tyres are up to on the road. This is one of the best frames I’ve ridden, from this point of view. The balance between stiffness and comfort is impressive, with each section of the frame and fork doing its specific job while still feeling like a complete package.

Compared with my TCR of the same size, the head tube of the Defy is 10mm taller, with an extra 15mm of stack height, so the riding position is generally more relaxed. It’s certainly still aero enough, though, with plenty of drop achievable between the saddle and the handlebar for you to get low in a headwind or to sprint in the drops.

And those few extra millimetres took the edge off my lower back and neck, so rides of three to four hours were more comfortable overall, and arguably more efficient.

With the semi-deep wheels added to the equation, the Defy is a bike that cuts through the wind well and on longer routes the differences in average speed between it and my TCR were negligible, highlighting just how quick this bike is from a real-world perspective.

Giant Defy Advanced SL 1: Frame & fork

Giant is one of the biggest bike manufacturers in the world, so it’ll come as no surprise that it creates its frames in its own factory. As the name suggests, this Defy gets the top-spec Advanced SL frameset which Giant describes as using professional grade raw carbon fibre sheets, with each frame’s lay-up using 132 separate pieces of composite.

Other than that, it doesn’t give away too many specifics on the carbon composite, which is understandable, but it claims a size medium frame weighs in at around 785g. The Overdrive Aero fork comes with a tapered steerer and weighs a claimed 345g.

Like most modern frames, the Defy runs its brake hoses fully internally, entering through the top of the head tube, accommodated by the D-section fork steerer. The frame is only compatible with electronic groupsets so there is unlikely to be any faff maintenance-wise, and if you do need to change the brake hoses, I found it relatively easy to do on my TCR, so I’m guessing it’ll be the same here. It certainly gives a clean look to the whole frameset.

The Defy uses a 41 x 86.5mm press-fit bottom bracket and integrated headset, and if you were to go for the frameset-only option (£3,499) then the D-Fuse SLR seatpost is considered part of the package. It’s designed to flex by up to 7mm, adding extra comfort to the ride. I found it worked well, providing a barrier to harsh vibrations without making the rear end of the bike feel soft or soggy. An adjustable position gives a setback range of -5/+15mm offset.

The Defy also has some slender seatstays to cushion the rider too.

As for mounting points, the Defy has a couple of positions for bottle cages and there are also mounts for mudguards, adding versatility for year-round riding.

A quick look inside the frame showed a clean finish – it’s a well-made bike – and the outside looks pretty impressive too thanks to the pearlescent paintjob for this model.

It’s available in four sizes: small, medium, medium/large and large. That covers top tube lengths of 530mm to 575mm.

This model here is the M/L, which has a 560mm top tube, 175mm head tube and a 515mm seat tube.

The head angle is 72.5 degrees while the seat tube sits at 73 degrees, and you are getting stack and reach figures of 577mm and 384mm respectively. That gives a ratio of 1.5, squarely where I’d expect it to be for an endurance bike. For comparison the TCR in this size is 1.43.

Other measurements include a 50mm fork rake, 70mm BB drop, and a wheelbase of 1,010mm, including chainstays of 420mm.

Giant Defy Advanced SL 1: Groupset

The Defy models are broken down into three tiers with the Advanced (£2,699-£3,699) at the lower end, Advanced Pro making up the middle ground (£2,799-£4,499) and these Advanced SL models claiming the top of the pack at £8,499 for this SL 1 and £11,499 for the SL 0. (Though there is some heavy discounting on Giant’s UK website at the time of writing, with this SL 1 reduced to £6,799.)

The SL 1 comes with a SRAM Force AXS groupset, albeit the previous generation, which we reviewed last year. No doubt new builds will incorporate the latest version of Force, which launched a couple of months back, with the key area being the updated lever shape that gives much more comfortable ergonomics and improved braking power, like that found on Red. We have a full review coming very soon.

As it stands, though, this bike uses a 2x Force crankset with 33/46-tooth chainrings mated to a 12-speed 10×36 cassette.

I like the smaller-ring setup of SRAM’s road groupsets as I find it efficient, using it more like a 1x system, with smaller jumps between the sprockets. The small chainring gives plenty of bailout gears, and the 10T sprocket keeps the highest gear large enough that I don’t run out of anything to push at high speed.

The battery range is excellent on both derailleurs and the shifters, and with the entire setup being wireless, adding a new component to the groupset is incredibly simple. You also get a power meter included and our previous testing has found SRAM’s offerings to be very accurate.

For stopping purposes Giant specs a 160mm rotor on the front wheel and a 140mm on the rear. That, to my mind, is the perfect setup for a road bike like this and has all of the power required, plus the modulation on offer is something that SRAM has improved over each version of its groupsets.

Giant Defy Advanced SL 1: Finishing kit

The rest of the components come from Giant’s own catalogue, like the seatpost I mentioned earlier.

The Contact SLR Aerolight stem runs the brake hoses internally so they can pass into the head tube. It keeps things looking neat, comes with an integrated computer mount and does the basic job that a stem needs to do, the main one being keeping the Contact SLR D-Fuse handlebar in place.

This bar is made from carbon fibre and weighs around 185g in a 420mm width. At £349 separately on Giant’s website, it’s not cheap either.

It has a drop of 125mm and 72mm of reach, so nothing out of the ordinary, but it does get 8 degrees of flare at the drops, something normally reserved for gravel bars.

A couple of years back I started using flared bars on any bike that I use for long rides, especially if I’m likely to be riding on poor surfaces or in wet conditions. I like the added stability the wider stance offers in the drops without affecting aerodynamics when riding on the hoods.

Bar width changes with frame size, starting at 400mm for the small, 420mm for the medium and medium/large, and 440mm for the large. Stems range from 90mm to 110mm.

The saddle is the Giant Fleet SLR and I got on with it well. It wouldn’t take the place of my favourites, but if I bought this Defy I wouldn’t be in a hurry to change it. Its slender shape makes it ideal for fast riding and the padding did a good job of providing comfort.

Giant Defy Advanced SL 1: Wheels & tyres

Giant also supplies its own wheels, in the shape of SLR 1 carbon rims with a depth of 36mm mated to Giant’s own hubs and 24 Sapim CX-Ray spokes front and rear. Individually priced at £1,200, this wheelset weighs a claimed 1,442g and has a weight limit of 129kg (285lb) to include the rider, bike and kit.

The rims have a 22.4mm inner width (26mm external), and being hookless in design means they are only compatible with tubeless tyres, regardless of whether you run them with sealant or inner tubes.

They seem to be decent wheels with no issues in terms of reliability or trueness, and with a relatively low weight they accelerate well and aid climbing too.

The Defy will accept up to 40mm tyres but comes with 32mm Cadex Classics fitted as standard, which measure up slightly larger when fitted, to just over 33mm.

I could tell they have been designed as an endurance tyre as opposed to all-out performance – the compound and carcass give a ride feel that only a tough tyre designed for robustness can, as in it’s not the most supple, which affects ride quality and rolling resistance.

If that’s what you’re after and you’d happily swap feedback and grip over the ability to run a single tyre year-round then the Classics will suit you. I think that they do this Advanced SL a slight disservice, though, in terms of what the bike is capable of. They are a bit dead feeling and take the shine off the performance of the bike – something I could easily tell when running the bike with a new set of Zipp 303 SW wheels with 32mm Goodyear Vector tyres fitted.

If you want to get the best performance out of your Defy, I’d definitely recommend changing out the tyres.

Giant Defy Advanced SL 1: Value

Most of the big bike brands have endurance-specific models in their range, so how does the Defy compare?

I’ve ridden quite a few of Merida’s Scultura Endurance models over the last few years, which are slightly more relaxed versions of its Scultura race bike. The Rival Edition is the most recent, and there are a lot of similarities to the Giant – mainly, the impressive ride comfort achieved by a frame that is big on feedback, and it being a capable machine at speed too. The tyre clearance is less at 35mm, but it will take mudguards, and has similar geometry to the Defy, especially at the front end.

The range tops out with the 9000 model, which comes with a Shimano Ultegra Di2 groupset, full-carbon cockpit, Reynolds ATR carbon wheelset and 32mm Continental GP5000 AllSeason TR tyres, all for a very competitive £4,950. That said, Merida gives a claimed weight of 8kg, so it’s heavier than the Defy, and the CF 3 frameset it uses sits below Merida’s ‘pro’ level CF 5.

Specialized’s take on the endurance theme is the Roubaix, a bike that Suvi was very impressed with when she reviewed it for us back in 2024. She rode the SL8 Expert model, which she praised for its smooth ride quality and the fact that it’s compatible with both electronic and mechanical groupsets (and has no internal headset cable routing). It, too, has 40mm tyre clearance and the ability to run mudguards, although the Future Shock system, which adds some damping comfort to the front end, also adds weight. The 49 size she tested weighed 8.5kg.

The Roubaix isn’t as roadie as the Defy, having much slacker angles and all kinds of mounting points added to the frame. It’s an endurance road bike edging towards allroad and light gravel, if you like. The Roubaix SL8 Pro build is similar to this Defy with a Force (the new E1 version) groupset, carbon own-brand wheels and a carbon handlebar, for £6,999.

Canyon’s endurance model is the Endurace. The latest version was released back in 2023, and I got to review the CFR Di2 model. Overall, I was impressed: it was comfortable to ride, pretty nimble and the Shimano Dura-Ace-equipped option I was riding was light at 7.5kg.

I did think it lacked rider involvement, though – the whole experience just felt a little muted. I put this down to the tall front end created by a 186mm head tube (611mm stack) on a medium, which put me in an upright riding position. It was almost a little too ‘endurance’ for me.

It’s more competitively priced than the Defy. The CFR models use Canyon’s top-end frame and costs £8,349 for both the Dura-Ace Di2 and SRAM Red options, which are both higher-tier groupsets than the SRAM Force on the Giant. Both get DT Swiss carbon wheels and a full-carbon cockpit. Canyon currently has an end of season sale on, with both CFRs reduced to £7,419. 

Last year I was impressed by the Argon 18 Krypton Pro. Like the Defy it looks and rides just like a performance road bike thanks to excellent frame stiffness and semi-aggressive geometry. Look closely, though, and you’ll find a bike capable of taking 38mm tyres and with mounts for mudguards. The geometry worked very well both on the road and away from it, if you fancy a bit of ‘allroad’ action.

The Ultegra model I reviewed weighed 7.4kg with the included toolkit hidden in the down tube internal storage section, and cost £7,000 with Hunt Aerodynamicist carbon wheels, while a SRAM Force AXS-equipped option comes in at £8,750 with a power meter and Zipp’s 303 Firecrest wheels.

I said at the start of this review that the Defy is an excellent option ‘if carbon is a must’, but if you are open to other frame materials then don’t discount the Fairlight Strael 4.0. Its steel frame makes it slightly heavier, but its geometry and riding style mean it’s very similar to the Giant out on the road, and it’s also the highest I’ve ever scored a bike.

The Shimano 105 Di2 model I rode weighed 8.8kg, but that was offset by incredible comfort and efficiency. It’ll take up to 39mm tyres and full mudguards, too. It’s a bit of an outlier against the Defy, but with a similar build costing just £4,589, the Strael is worth a mention as a fast-riding option with an endurance setup.

Giant Defy Advanced SL 1: Conclusion

Over the years Giant has proved that it is up there with the best in terms of frame design when it comes to blending comfort, stiffness and performance with seemingly little in the way of compromise. That doesn’t change here.

The Defy is a stunning bike to ride, whether you want something efficient to ride hard or to head out for multiple hours and not get beaten up on rough roads. At full price it’s at the upper end of the market, and there is some really tough competition if you are willing to make a few sacrifices.

If you can get a good deal, though, the Defy is arguably the pick of the bunch in the carbon endurance options.

Verdict

Stunning performance – a great blend of stiffness and comfort without compromising engagement between bike and rider

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