Specialized launches revamped Diverge STR gravel bike with all new radical rear suspension system

In Specialized's bid to prove that "smoother is faster", the new Diverge STR gains an all new Futureshock system at the rear as well as the front to give the bike a silhouette like no other. With space for 700x47c tyres, 20mm of suspension at the front and 30mm round the back, is this the most mountain bikey gravel bike from a big brand yet?

> Check out our first ride review too: Specialized Diverge STR

Hot off the back of the radical-looking new Bianchi Oltre, Specialized too has thought it would join the divisive aesthetics party.

The hydraulically damped elephant in the room of course is that rear suspension system; Specialized says that this is "more compliant than any drop bar bike [they] have ever made, yet adds just 100 grams compared to the outgoing S-Works Diverge frame."

That gives the new FACT 11R Rigid Carbon Frame a claimed weight of 1,050g, although a closer look indicates that it'll be 1,100g by the time it's painted (Size 56cm frame) with no hardware and the complete frameset (including future shock systems) is just under 400g heavier than the standard S-Works Diverge, a bike that made it into our best gravel bikes buyer's guide.

The rear Futureshock system also once again sets the Diverge on a separate path to the Crux. The now previous generation Specialized Diverge and latest generation Specialized Crux had grown very similar, converging on a design with 700x47c clearance, that said this new design also gets clearance for 47mm tyres or 2.1" rubber on 650b rims.

Specialized says that "never have so few grams added so much capability. Climb it, race it, or load it down with bags and gear for the long haul, Diverge STR does it all faster and smoother without any excess baggage".

Of course, this is by no means the first time that we've seen gravel bikes try and boost compliance. The Lauf Seigla, for example, has a large focus on boosting rear compliance and uses a unique front fork design to provide 28mm of travel. The Cannondale Topstone and Niner MCR 9 RDO meanwhile have been boasting full rear suspension systems for some time now, offering 30 and 50mm of rear wheel travel respectively.  

THAT rear suspension system

The somewhat unconventional looking 30mm of rear travel is no better described than in the above video. As the rear wheel impacts a bump, it moves up. The ‘framepost’ works a spring, moving backwards in response. Its direction of travel is equal and opposite to the wheel’s path.

The damper controls the movement of the framepost backwards and forwards. According to Specialized, this ensures that the rider maintains the same position in space.

The system is fully tunable for rider weight, height and riding style with on-the-fly adjustability. It's also compatible with a 27.2mm dropper post. A lever on the damper provides three levels of compression damping, while rebound speed can be adjusted (not on the fly) with a hex key through a hole in the base of the top tube

The Diverge STR will ship with two frame posts, that Specialized expects will "well-serve" most riders. If that doesn't work then there is, in fact, a total of nine frame posts each with different layups, to have "unique stiffness profiles". Additionally, each frame post has two different stiffness settings, depending on its orientation. Talk about complicated!

> Staff Bikes: Jamie's custom Lauf Seigla gravel bike

Specialized says that they have "put tremendous focus on making the Diverge STR reliable and easy to live with." and that "the entire system is meant to last a long time without service or any special maintenance."

With this in mind, like on the front Futureshock 2.0 system, the damper itself is not serviceable and is considered a wear item. This was in fact one of the main drawbacks and reasons for selling my own hardtail Diverge, but only time will tell just how durable this new system is.  

Specialized says that by "suspending the rider with damped, tunable travel (20mm front / 30mm rear), Future Shock Technology absorbs bump forces to boost your control and capability while retaining efficiency and responsiveness of a rigid frame because as far as power transfer goes, it is a rigid frame.

"Power to the pedals makes the bike jump like a scared cat. You’re efficient, you’re comfortable, you’re in control. Your bike is light, nimble, and responsive."

> 8 tips to get started with gravel riding

The brand has supplied the above graphs and data to back up its claims, and below you can see the bike from which it gathered the data. There's just something quite cool about a test mule bike!

The rest of the bike...

I'm afraid the rest of the bike gets a fairly short section simply because most of the tech here has remained very similar to the standard Diverge. As previously mentioned the STR retains the 20mm Futureshock 2.0 system at the front and 47mm of tyre clearance. The internal SWAT compartment also remains in the downtube to provide storage for tubes, tools, jelly babies... or whatever else people like to put in there. 

As this is a bike that Specialized says is capable of serious endurance rides, there is also a fair few mounting points. Mounting points on the forks and top tube can accommodate a front mudguard, bento box and fork storage solutions, but many will be disappointed to find that there are no mounts for a rear mudguard thanks to that new suspension system.

> Endurance Bikes vs Gravel Bikes

Geometry

Specialized says it wanted the new travel to eliminate bobbing under power and ensure big hits never catapult you from the saddle, without compromising fit or pedalling efficiency. As such, the stack and reach of the Diverge STR is the same as other Diverge models, and bike sizing is meant to be consistent between them.

> How to read a bike geometry table: the numbers made easy

You will notice from the geometry that there are a few minor differences when compared to the latest hardtail Diverge: The BB drop is increased from 80 to 85mm, the chainstay length has increased from 425mm to 429mm and the seat tube angle is ~0.5 degrees steeper. Specialized says that this change in seat tube angle is to "compensate for sag in the STR system in the static position so that your sagged riding position ends up the same between bikes."

Tech Specs

• Futureshock 2.0 system
• 27.2mm seatpost (With compatibility for dropper post)
• 68mm BSA threaded bottom bracket
• Tyre clearance 700 x 47c / 650b x 2.1" (With 6mm clearance either side)
• Flat mount brakes (160/180mm front)
• 125kg weight limit
• 100x12/142x12mm dropout spacing
• Claimed frame weight: 1,100g 
• Sizes: 49, 52, 54, 56, 58, 61cm

Pricing and weights

The Diverge STR will be offered in three variations, S-Works, Pro and Expert. A complete 56cm S-Works Diverge STR has a claimed weight of 8.5kg set up tubeless out of the box. Meanwhile, Pro and Expert models come in at 8.9kg and 9.5kg, respectively.

S-Works (£13,000)

As usual, the S-Works model sits at the top of the range and at launch is available in just one colour option, Satin Forest Green. The S-Works model gets the same FACT 11R frame as the rest of the range but benefits from carbon Roval Terra CLX wheels, carbon Roval Terra bars, S-Works Power saddle and a mullet Sram Red eTap AXS groupset with Sram XX1 Eagle rear mech.

Pro (£9,000)

The Pro model is the loudest of the lot in this Satin Blaze/Violet Ghost Pearl Fade colourway. It too gets carbon wheels in the form of Roval Terra CLs, the same carbon Roval Terra bars, saddle and S-Works carbon seatpost. The Pro model ships with a Sram Force eTap AXS groupset with Sram X01 Eagle AXS rear mech.

Expert (£7,500)

The Expert model is offered in two colours, Satin Harvest (above) and Satin Black (below). The Expert range gets more relaxed alloy hover bars, carbon Terra C wheels and a Sram Rival eTap AXS groupset with NX Eagle rear mech. Like all of the Diverge STR models, the Expert comes with 42mm Tracer Pro 2BR tyres.

Full build specs and more information can be found on the Specialized website. We've already got a bike on it's way for further riding, so expect a full review in the coming weeks.

What do you make of the new bike? Has Specialized solved your gravel woes or is it barking up the wrong tree? Let us know in the comments section below...