Specialized Diverge STR review

The Specialized Diverge STR (‘suspend the rider’) is a full carbon gravel bike with a unique front and rear suspension setup that aims to isolate the rider from bumps without sacrificing the tautness of a rigid frame.

It’s a fascinating piece of design that goes that bit further to bridging the road–MTB divide, and its approach to rider comfort works well in the real world.

My first impressions from riding the flagship S-Works Diverge STR, with SRAM Red and Eagle eTap AXS, at the launch in Germany’s Black Forest, were largely positive. Having since spent some time in the UK with the considerably more affordable Diverge STR Expert, my views remain much the same.

It’s a remarkably capable bike with some really clever tech, but not necessarily what all riders will want from a gravel bike. Also, the cheaper Expert model offers so similar a riding experience – it gets the exact same frameset, similar wheels and a groupset that shifts just as well – that it makes the S-Works look like relatively poor value for money. Both bikes feature here, so you can have fun playing spot-the-difference.

For a full introduction to this rather special bike, don’t miss our Specialized Diverge STR launch story and our deep dive on the new suspension design.

Specialized Diverge STR frameset

The Diverge STR’s USP is its Future Shock suspension. At the front end it uses the same Future Shock 2.0 system as the previous generation Diverge to suspend the cockpit, while rear-end squish is supplied by a flexible ‘frame post’, its movement controlled by a tiny damper mounted at the rear of the top tube.

The damper features on-the-fly adjustable compression damping (compression of the system, ie, extension of the damper) and tool-adjustable rebound damping.

A slender aluminium bridge Specialized calls the ‘tendon’ joins the frame post to the damper and the whole setup is said to offer around 30mm of travel at the saddle.

Every Diverge STR ships with two frame posts of different stiffnesses, and each can be mounted in two orientations according to the amount of flex desired, meaning riders have four levels of squish from which to choose.

Take the rear suspension out of the equation and the Diverge STR’s frameset strongly resembles that of its predecessor, sporting many of the same practical features including a smattering of mounts (front rack or guard? Yes. Rear mudguard? No), SWAT in-frame storage and clearance for 700 × 45mm or 650 × 2.1in tyres with room to spare.

Specialized designates the Diverge STR’s carbon as FACT 11r, nominally one tier below the top-spec 12r of the S-Works Aethos and S-Works Tarmac SL7.

We wouldn’t read much into this, however, given that the designations are arbitrary and Specialized doesn’t share specific details of how the layups differ.

Specialized Diverge STR geometry

Specialized says the Diverge STR offers exactly the same fit parameters as the previous Diverge, and minor differences in the precise numbers are by-products of the new suspension layout.

The Diverge STR is a unisex design and on paper it doesn’t offer the most radical set of figures – reach for a 54cm is a fairly modest 383mm (some brands are now pushing well past 400mm in tandem with shorter stems, a trend borrowed from mountain bikes) while stack is lofty at 593mm.

A trail figure of 61mm for this size puts the Diverge at the faster handling end of the gravel spectrum, similar to the racy Cervélo Áspero-5 (58.6mm).

By default my 54cm test bike would come with an 80mm stem but knowing I invariably feel cramped on stock 54s from the brand I requested a 110mm, which felt just right.

Specialized Diverge STR build

S-Works Diverge STR

The top-spec Diverge STR gets a full SRAM eTap AXS mullet drivetrain, combining road Red eTap levers with an Eagle XX1 AXS rear derailleur and a huge 10-50 12-speed cassette.

With a 40-tooth chainring, this setup affords you some very low gears – ie, gear inches in the low 20s.

The wheels are Roval Terra CLXs, the flagship gravel option from Specialized’s in-house brand. These feature a hooked low-profile carbon rim with a very gravelly internal width of 25mm.

Specialized is speccing its newly updated Tracer Pro 2Bliss tyre on the Diverge, a slightly more all-round option than the slick-centred Pathfinder previously favoured, albeit still one with a fairly low-profile tread.

Finishing kit is all in-house as you’d expect, including the latest S-Works Power with Mirror 3D-printed saddle.

It's worth noting this isn’t sitting atop the flexy Roval Terra seatpost – because the frame post adds so much flex of its own and it's tailored to the Future Shock damper, Specialized recommends against fitting the Terra post to the STR.

Diverge STR Expert

The Expert gets an identical frameset, but trades down to a SRAM Rival / GX Eagle AXS groupset, Roval Terra C wheels, alloy bars and a standard Power Expert saddle rather than the posh 3D-printed one.

Riding the Specialized Diverge STR

You notice the rear suspension as soon as you sit on the Diverge STR because, like all proper suspension, it sags.

The jaunty angle of the saddle in the photos of the S-Works bike reflects that. I tend to err on the side of very slightly nose-down anyway and the setup pictured gave me this once I put my weight on it, with the softer frame post fitted. The Expert model was shot with the stiffer frame post installed and I didn't need as extreme a setup to compensate.

You notice the flex as soon as you start riding too, and not in a bad way; ‘suspend the rider’ feels very apt – even riding on smooth German tarmac on the launch I had the sense I was floating above the bike but not that I was sitting on an uncontrolled spring.

The STR really does preserve the responsiveness of a rigid road-style frame in a way that’s simply not possible with conventional mountain bike-style rear suspension, because standing takes the rear Future Shock out of the equation completely.

The sitting-standing dichotomy

Sit your butt on the saddle and things get more nuanced. The precise feel will depend on a number of factors – which version of the frame post do you have? What compression and rebound settings have you chosen? – but certainly at first blush the rear suspension does a remarkably good job of shielding you from bumps without ruining your pedalling and it moves with zero perceptible stiction (where friction of moving parts inhibits damping).

I did experience a small amount of saddle bob when I was winching myself up steep, rocky climbs but in such a way that barely affected my ability to put down power – it’s really not comparable to the watt-sapping movement you’ll experience on some full-suspension mountain bikes.

The compression adjustment has an obvious effect on the overall feel, but I didn't find it particularly useful to switch modes on the fly, instead preferring to leave it in the fully open position most of the time to take maximum advantage of the suspension.

Because the STR system only helps you when you’re seated, it creates a perverse incentive not to stand, instead encouraging you to exploit the mullet gearing and grind steadily up climbs in a manner that’s ultimately almost certainly faster than choppy out-of-the-saddle efforts over bumpy terrain.

This incentive extends to fast riding on the flat and to descending as well up to a point, which feels counterintuitive. Standing on descents is the default option for technical terrain and usually the best way to retain control – your legs are the best suspension you have, after all, and you can adjust your weight distribution.

The Diverge tempts you to sit more, but of course you don’t want to be on the saddle for really big hits that might launch you upwards and forwards. As a result, some mental recalibration is required, and it's something I never entirely stopped thinking about entirely during my time with the bike.

In any case, the Diverge STR excels at riding quite quickly over rough ground, and we all enjoy that, right?

Future Shock 2.0? Still excellent

I’ve naturally focussed on the rear suspension but the front Future Shock carried over from the previous model still works really well.

Yes, it can bob a little when you’re climbing out of the saddle, but I’ve spent enough time with the system on previous models to acknowledge this isn’t really an issue in the real world, and the overall gain in rough-road performance is worth it.

I'm a big fan of the Future Shock-equipped Roubaix endurance bike incidentally, which suffers slightly more from this bob – although it's still not a problem – which I believe is because the Diverge gets a stiffer spring to prevent bottoming out.

It's worth pointing out, however, that while the markings on the Future Shock knob give the impression that its damping is continuously adjustable, this is a red herring, and it's essentially a primitive on/off lockout. Like the rear damper adjustment, I've generally found it best to leave it open at all times.

• Buy Specialized Diverge STR Expert from Tredz for £6,299
• Buy Specialized S-Works Diverge STR from Tredz for £13,000

Specialized Diverge STR review verdict

The Diverge STR is a seriously capable and hugely enjoyable gravel bike that retains the best bits of the outgoing model.

I’m not completely sold on the looks – the exposed rear shock gives the bike a slightly prototypey vibe – but I understand why Specialized’s engineers wanted to show off their work, and covers come with their own drawbacks.

I’m also slightly surprised Specialized hasn’t adopted more progressive geometry when rivals are pushing reach figures ever longer in combination with stubby stems, in search of more confidence-inspiring handling on technical terrain. A 54cm Trek Checkpoint goes 20mm longer for example, with 403mm of reach.

This more conservative approach doesn’t hold the Diverge STR back in any way, however. It’s the riding that matters and the previous Diverge was one of my favourite all-round gravel bikes despite its relatively conventional geometry.

The Expert spec highlights a curious side-effect of trickle-down bike tech. While heavier than the £13,000 S-Works (10.1kg vs. roughly 8.5kg), its frameset, shifting feel and braking are identical. Having tested both, the Expert gives up nothing in the ride experience to the flagship and saves you a mind-bending £5,500. I know which one I’d choose.

The big question for riders will be whether this high-tech approach is what they want from the genre. 'Gravel bike’ can denote anything from a road bike with fat tyres to a mountain bike with drops. Some riders equate gravel with pared-back simplicity but there’s no single right tool for the job.

It’s certainly not pared back and simple, but the Diverge STR is a seriously clever piece of design and it will delight riders who want a fast and comfy all-rounder.

Specialized Diverge STR Expert spec

Brand	Specialized
Price	£7,500 / $6,700 / €7,500
Frame	S-Works Diverge FACT 11r carbon
Fork	FACT carbon with Future Shock 2.0
Weight	10.1kg
Sizes available	49, 52, 54, 56, 58, 61
Levers	SRAM Rival eTap AXS
Brakes	SRAM Rival eTap AXS w/160mm rotors
Rear derailleur	SRAM GX Eagle AXS
Crankset	SRAM Rival 1 Wide 40t
Bottom bracket	SRAM DUB BSA 68
Cassette	SRAM NX Eagle 11-50 12-speed
Chain	SRAM GX Eagle
Wheels	Roval Terra C
Tyres	Specialized Tracer Pro 2BR 700c×42mm
Bars	Specialized Adventure Gear Hover
Stem	Specialized Future Stem
Seatpost	S-Works carbon
Saddle	BG Power Expert

• Buy Specialized Diverge STR Expert from Tredz for £6,299 (RRP £7,500)

Specialized S-Works Diverge STR spec

Brand	Specialized
Price	£13,000 / $14,000 / €15,000
Frame	S-Works Diverge FACT 11r carbon
Fork	FACT carbon with Future Shock 2.0
Weight	8.5kg claimed, 9.6kg with pedals, cages, various items in SWAT storage
Sizes available	49, 52, 54, 56, 58, 61
Levers	SRAM Red eTap AXS
Brakes	SRAM Red eTap AXS w/160mm rotors
Rear derailleur	SRAM XX1 Eagle AXS
Crankset	SRAM Red 1 AXS 40t
Bottom bracket	SRAM DUB BSA 68
Cassette	SRAM XS-1295 12spd 10-50
Chain	SRAM XX1 Eagle
Wheels	Roval Terra CLX
Tyres	Specialized Tracer Pro 2BR 700c×42mm
Bars	Roval Terra carbon
Stem	S-Works Future Stem
Seatpost	S-Works carbon
Saddle	S-Works Power with Mirror

• Buy Specialized S-Works Diverge STR from Tredz for £13,000

Don't miss our in-depth look at the development process that led to the creation of the rear Future Shock