[Review] Specialized Demo 11

We rarely test downhill bikes here at MTB Mag, but in the case of the Specialized Demo 11, everything has fallen into place – both because we finally have a tester for this type of downhill bike, and because two solutions adopted by the Californian brand’s engineers deserve a great deal of attention: the OBB suspension and the HighGear drivetrain.

A video is the best way to see how they work, not least because I’ve removed the HighGear cover to show you the three (!) chains used to transfer power from the pedals to the rear wheel whilst simultaneously decoupling the suspension from the drivetrain. A design developed in collaboration with SRAM, which has the added benefit of providing plenty of ground clearance around the bottom bracket and keeping all the weight as low as possible, giving the bike excellent stability. You can tell it works right from the first 30 seconds of the video.

There’s only one model available for now: the S-Works version you see here, priced at €12,499, or you can buy the frame on its own for €7,499. These are certainly not budget-friendly prices for a discipline like downhill, where bikes are put through their paces and which is aimed at a young audience; let’s just hope that in future the Demo 11 will also be available in more affordable configurations. Personally, I think its design is very well executed and stylish, and I’m pleased to see that bikes without motors and batteries are still being developed. Who knows if some of these features might find their way onto an enduro mountain bike, especially considering that Specialized’s last bike of that type is now more than six years old.

Geometry

The bike under review is size S3 (there are three sizes: S3, S4 and S5) and weighs 18.6 kg without pedals on our scales. If you remove the cover from the HighGeart gear, you can see how this system works: the crankset drives a small compact chainring connected to an internal lower pivot. Inside, two chains transmit power upwards to a shaft, to an intermediate drive pin. Essentially, we have a high-pivot system housed within the bottom bracket shell.

If you look closely at the video, there are actually three chains: one is the drive chain, which drives the rear derailleur, whilst the other two are the internal chains within the HighGear system. There are two because SRAM, which was involved in developing this system, realised that with just one chain, the system began to act in a laterally unbalanced manner; in other words, there were lateral forces that prevented the two sprockets from remaining properly centred. By using two chains, therefore, we’ve managed to keep the chain’s movement and the force it exerts firmly centred.

What is the advantage? First and foremost, the drivetrain is completely decoupled from the suspension. Consequently, there is no pedal kickback, and the bottom bracket has greater ground clearance – 30 mm more than before – partly because the chainring is very small. Moving on to the suspension system, the OBB has a very interesting feature: at the start of the travel, it is retrograde, meaning the rear triangle extends – that is, the rear wheel moves backwards before following the classic upward trajectory. This means you can tackle square obstacles such as steps or large boulders without any major problems. In other words, you don’t get that sensation of the rear wheel digging in, which you might experience with other systems.

Aside from the OBB system, the rear triangle features the classic Horst joint found on all Specialized bikes except the XC models. Looking at the frame, it’s made entirely of carbon and features a mullet wheel set-up. It has a very sleek design. On the trail, here’s what Oscar had to say – he managed to ride in Lenzerheide and Chur even after the end of the competitive DH season in which he competes. Unfortunately, this bike arrived in October, so we weren’t able to test it in a race; however, by trying it out on the trails and, above all, on the downhill runs he usually uses for training, he was able to tell me what makes this system different.

The first thing that stood out was that this bike is literally glued to the ground; in other words, in rock gardens or on uneven landings, it doesn’t lose its composure, thus allowing the rider to choose lines that are even a bit more extreme than they could on other bikes. It’s also very quiet. When cornering, as the centre of gravity is very low – with all the weight of the drivetrain and shock absorber positioned very low down – it’s incredibly stable; it’s easy to carve into corners and, above all, hold your line even on rough bends.

On the climbs, the rear end bobs noticeably. Then again, chain pull is practically eliminated by the HighGear system, and it’s clear that this isn’t a bike designed for pedalling. This point can be applied to enduro, as some might wonder whether we’ll see this system on enduro bikes: it’s unlikely, not only because of the lack of chain tension, but also because all these derailleurs and chains increase friction. In downhill riding, this is a negligible factor because you do very little pedalling, but in enduro it would be a very important consideration.

The compression curve on this Specialized Demo 11 is 24 per cent, a compression setting that Oscar found comfortable. We fitted a spring suited to his weight to achieve a SAG of 30 per cent. He told me it’s difficult to reach the end of the travel, so it’s nicely progressive at the end of the travel – which is crucial given the many jumps in downhill riding. However, the thing that bothered him was the aluminium handlebars; being used to carbon handlebars that absorb vibrations well, the aluminium handlebars on this Demo 11 meant that Oscar’s hands were aching by the end of the day.

The wheels are also made of aluminium, which is fine in itself as aluminium is usually a bit less stiff than carbon, but he told me they were actually too stiff for his liking. Bear in mind that Oscar weighs 60 kg, so he’s a bit of an atypical rider when it comes to DH – after all, he’s only 15. He did manage to dent the rear rim, though the rim remained true after fitting the plug to repair the rear tyre. The tyres are Specialized Cannibals with an excellent, very soft compound. This bike has also been ridden in wet conditions, and Oscar assured me that the wet-weather grip was really good.

The suspension is nothing new to our tester, as it’s the same suspension he uses on his own DH bike. He’d added a mass damper which, according to Oscar, makes the bike more stable – even more so on rough terrain.

The new SRAM XX downhill groupset was highly appreciated because it has no derailleur hanger; therefore, even in the event of a crash or impact with rocks, it doesn’t bend, so it always remains in perfect condition. What’s more, it’s high off the ground, nice and compact and features an electronic drivetrain – so with the electronic remote control, there are no cables to adjust or calibrate depending on how much you use the drivetrain. It was really easy to keep the drivetrain running perfectly at all times.

Conclusions

This is a very successful DH bike. The technical solutions are very interesting. After all, it was used for two or even three years by the Specialized Gravity team with Loic Bruny before being launched on the market. It’s fair to expect that it has been thoroughly tested, and here we can say that the result is excellent. Leaving the price aside for a moment, I must give credit to Specialized for continuing to develop non-electric bikes with innovative technological solutions. This is something that drives the cycling world forward and offers a glimmer of hope for those who want to ride mountain bikes without a motor or battery.