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Giant Contend SL2 Disc Review: 2017

 Side view of a Giant Contend SL2 Disc road bike leaning against a fence in the Autumn

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The all-new Giant Contend range for 2017 replaces the aluminium Defy. At under £1000 the Contend SL2 Disc is just within a Cycle To Work scheme budget, but how does this bike perform on the road?

Model: Giant Contend SL2 Disc

Year: 2017

Intended use: Road-Endurance

Price: £999.00SRP*

Throughout its lifetime, the aluminium Giant Defy range was consistently a top scoring best-seller bike. Giant’s excellent build quality, feature-laden frame design, and high-spec components at competitive prices contributed to the Defy’s success. That leaves the new Contend with some pretty big boots to fill…

Giant Contend SL2 Disc road bike leaning against a fence on a cycle path in the Autumn

All-day comfort. The Giant Contend SL2 Disc is a real mile-muncher.

Tech spec

The Giant Contend SL2 Disc is made from the same ALUXX-SL grade aluminium (6011 alloy if you’re interested) as the outgoing Defy 2 Disc, with the same ‘Hybrid Composite’ fork (carbon legs, alloy steerer). The frame is available in five sizes using Giant’s familiar Compact Road Design sizing, which will be familiar to a lot of riders. For those who aren’t, Giant use smaller tube lengths to achieve their frame geometry which results in lighter and stiffer bikes, but if measured using conventional methods the frames come out very small. According to Giant, their equivalent ‘conventional’ frame sizes work out like this:

  • Small is equivalent to a 51-54cm conventional frame
  • Medium: 55-57cm
  • Medium/Large: 57-59cm
  • Large: 58-60cm
  • XLarge: 61-63cm

Compared to the outgoing Defy, the Contend has lost the ultra-slender style around the seat stays and top tube, particularly where they both intersect the seat tube. This can partly be attributed to the integrated seatpost clamp on the Contend, which looks much neater than on the previous model but buries the wedge-clamp into the top of the seat tube.

That’s not to say that the Contend has an overweight or bloated look about it – this is still a slim machine. Giant’s D-Fuse seatpost is, as the name suggests, D-shaped with the flat section at the rear to promote vertical compliance in the saddle. The Contend also gets flat-mount brakes and internal cable routing, cleaning up the lines of the bike and lending it a premium aesthetic. It also keeps your precious cables away from the front-tyre spray.

Giant Contend SL2 Disc road bike close up of the internal cable routing and head tube welds

Neat and tidy: Internal cable routing and smooth, but reassuringly big welds.

In an ‘on paper’ comparison, the Giant Contend SL2 Disc comes out on top compared to its peers. The Cannondale Synapse Disc Tiagra and CAAD Optimo models are virtually the same price, but use an entry level mechanical disc brake and an alloy seatpost. The Scott speedster 20 disc is exactly the same price, with mechanical brakes and an alloy seatpost, although it does have a full carbon fork including steerer. The Cube Attain Race Disc has full hydraulic brakes, but costs £100 more. The GT Grade Tiagra comes close, with a dual-piston TRP Spyre mechanical brake and £50 to put back in your wallet.

The Contend SL2 Disc has full 20 speed Tiagra gears and doesn’t scrimp on the matching Tiagra chainset. Giant’s SR 2 disc specific wheelset is deeper and more aerodynamic than other models at this price point, and comes shod with Giant’s own front & rear specific P-SL1 tyres. You’ll find this rubber on several Giant road bikes from new, and they’re generally well-regarded for grip and puncture protection.

Giant Contend SL2 Disc road bike wheelset close up

The SR 2 wheels and P-SLR1 tyres perform well, but are a little weighty.

One thing I would have liked to see on the new Contend is the inclusion of thru axles on the disc brakes. Although it does add a little weight, it makes a lot of sense to stiffen up the bike near to where the braking forces are acting, keeping everything nice and tight when the anchors are dropped. However, the omission of these isn’t an oversight by Giant. They believe that current thru-axle designs, which come from mountain biking, are over engineered and unnecessary on a road bike. There’s a lot of sound reasoning behind that.

“Giant believe that current thru-axle designs, are over engineered and unnecessary on a road bike. There’s a lot of sound reasoning behind that.”

The eagle-eyed of you might have noticed something odd poking it’s nose out from the handlebar of the Contend SL2 in pictures of the Contend Disc models. Here in the UK, we’re very lucky to get a version of the contend SL2 Disc supplied with the Giant Conduct hydraulic brake system. For other regional markets, the Conduct brakes are the reserve of the flagship Giant Contend SL1 Disc model prices at £1,149.00SRP*.

Giant’s Conduct hydraulic disc brakes are best described as semi-hydraulic. They use the regular cable-operated Shimano Tiagra brake levers, with short cables running into a pair of hydraulic master cylinders built into the stem cap. These then feed hydraulic fluid hoses the rest of the way to the flat-mount calipers.

The genius of this system is fourfold.

  1. With only a short length of cable, there is very little cable stretch to dampen the feeling in the brake levers.
  2. The twin-piston hydraulic caliper is self-adjusting, so there’s no need for the periodic tune-ups you get on mechanical brakes.
  3. Compared to calipers with in-built master cylinders, the larger volume of hydraulic fluid improves thermal management.
  4. By supplying the bike with less expensive cable-operated Shimano levers, the retail price can be kept low, making the Contend SL 2 Disc the top performance road bike available for less than £1000.

Admittedly, this system also results in some of the Contend’s few downfalls. The conduct brake system doesn’t lend itself terribly well to being serviced, if and when the time comes. For the experienced mechanic, it’s a new system which may take one or two tries to get right. For the average DIY’er, a simple bleed or fluid top up will likely mean forking out for someone else to do it. Thankfully, if you buy your Contend from Wheelies, it will be delivered fully set up and ready to go.

Then there’s the stem. If you want to use an aftermarket stem that’s a little longer or shorter, you’re stuck with the sizes offered by Giant. You can still flip the stem upside down if you want to set your bike up with a rise as the Conduct stem cap can be mounted both ways.


Aside from the brakes, so far on paper there’s not an awful lot setting the new Giant Contend apart from the outgoing Defy. That changes when you take a closer look at the geometry tables.

The chainstays on the contend are a full 10mm shorter than they were on the Defy, bringing the rear wheel closer to the rider and creating a more nimble and agile feeling bike. The standover height has been reduced by between 11mm and 50mm (depending on size) too, which puts more of the bike’s weight closer to the road.

“The new Contend takes the old Defy’s admired all-day-comfort & mile munching capability, and sharpens up the handling.”

The Contend takes the Defy’s admired all-day-comfort & mile munching capability, and sharpens it up a bit in the handling department. It seems Giant are focussing the Contend more towards the road side of endurance riding, while the wide-tyre AnyRoad and Revolt models take care of the gravel/adventure roles.

Giant contend SL2 Disc road bike seat tube and seat stays close up

Giant’s D-Fuse seatpost is made from carbon, and promotes vertical compliance for comfort.

The Ride

The first thing you’ll notice aboard a Giant Contend SL2 Disc is how smooth it is to ride. It’s very smooth! In fact I feel like that’s a bit of an understatement. On the pothole-ridden roads of the local trading estate, the Contend is quite possible the most comfortable road bike (with a sub 32mm tyre) I’ve ridden. The outgoing Giant Defy was always a smooth bike to ride too, particularly the later models when the tyre size was bumped up to 25mm – it just seemed to enhance the feeling of the already comfortable riding position so well.

The new Contend is better still, and yet, when you’re out of the saddle and putting the hammer down, the power transfer and rigidity of the rear triangle are equally impressive. The shorter chainstays at work! Typically, on a non-carbon bike where there’s more weight higher up in the frame, standing up and heaving the bike with your arms can feel a little bit like stirring molasses – there’s a feeling of resistance, almost like friction, which keeps the bike from wanting to move. A good aluminium frame will alleviate a lot of that feeling. The Contend almost wipes it out completely.

I say almost… It is still  an aluminium frame and you can’t pretend it isn’t. Nevertheless the Contend SL2 Disc shows just how far alloy has come in recent years, and is an excellent showcase of Giant’s prowess with the material.

Giant Contact Forward saddle fitted to a giant Contend SL2 Disc road bike

Giant’s Contact Forward saddle is a vast improvement on their old Performance Road saddle.

The contact points on the Contend are typically Giant too – comfortable and functional. The Giant Contact Forward saddle on the 2017 Contend SL2 Disc is noticeably more comfortable than the Performance Road saddle used on Giant’s road bikes for the last few years. Gone is the flat top of the old seat which has been replaced by a pressure-relieving groove. It looks a lot neater & sportier too.

Shimano’s latest Tiagra 4700 gears and shifters are superbly reliable and have a much lighter and quieter touch between gears than previous generations. The gear change quickly, with no fuss, and not once were any adjustments needed on the cable after the initial setup.

“The Giant Contend SL 2 Disc rides in almost complete silence.”

Quiet is an important point to note here – the Giant Contend SL2 Disc rides in almost complete silence. Although initially it felt like the rear freehub needed a couple of miles to bed in and overcome a little friction, the Contend glides quietly over the asphalt.

Giant have been producing their own wheelsets for years, so they’re pretty clued up on how to build them. The SR 2 wheels are great for the price, if a little weighty. They’re not a full-depth aero shape so there’s no issues with crosswinds. It’s difficult to say much more – they’re there, they’re plenty strong enough, and they do exactly as they’re supposed to. Giant’s P-SL1 tyres are fantastically grippy – it’s nice to see a road tyre with no tread on it. I can’t comment on how puncture resistant they are other than to say I didn’t have any puctures on them.

The Giant Conduct brake system

It can’t be ignored any longer – we have to talk about Giant’s new brake system fitted to the Contend. As already mentioned, the Conduct brakes are Giant’s own creation (in partnership with brake experts Tektro) which allows a mechanical shifter to operate a hydraulic caliper. On paper, there are a lot of good reasons for such a system – added stopping power, responsive feeling, self-aligning pistons, reduced costs.

Giant conduct brake system close up, fitted to a Giant Contend SL2 Disc road bike

The Giant Conduct semi-hydraulic brake system hides 2 master cylinders in the stem cap.

If you’ve read my previous blogs, you’ll know that I like my brakes to be super responsive – very powerful and with a light touch because I have fairly small hands (feel free to add your own jokes here). The Giant conduct is certainly much sharper and more responsive early in the lever stroke than a fully mechanical disc brake, but there’s no denying that there is still a cable between your hands and the calipers when you’re trying to brake hard.

Not that this detracts from what Giant have done – the Conduct system is the perfect balance between expensive full-hydraulic brakes and cheap & low quality mechanical brakes, albeit with some compromises on ultimate brake responsiveness and maintenance complexity. What I will say is, when you’ve got the choice of a disc brake or a rim brake bike at similar prices, it seems silly not to opt for discs for UK riding. In the wet, they are a real godsend.

The bottom line

The Giant Conduct SL2 Disc is simply superb. For under £1000 you get one of the most comfortable ‘proper’ performance road bikes (with a tyre under 32mm), a wonderfully responsive frame with a featherweight touch, semi-hydraulic discs which far surpass their mechanical counterparts, Shimano’s lovely Tiagra 4700 groupset, and an all-round wonderful bike to ride.

I had to look hard to find any real faults with the Contend, and at most I could say the Conduct braking system still maintains some of the stretchy-cable feeling of a mechanical disc under hard braking. Other than that, I cannot fault the Giant Contend SL2 Disc. Certainly not for the price!


5 out of 5


Written by Guy Brooke
*SRP correct at the time of publishing