The best all-arounder?
Without wasting no time I will say that this is one of the most, if not the most comfortable stock gravel bike you can buy right now. Why? Let me explain…
A great gravel bike is for me something like a swiss knife that has to be very good at many different things. It has to be fast but at the same time, it has to be fun to ride. On many different occasions. There are gravel bikes that are definitely fast and fun on smooth roads (like Cervelo Aspero). There are bikes that should be great for a serious off-road riding like BMC URS or, even more, Niner MCR RDO. And there is a lot of bikes in between. But to be a great all-around gravel bike it has to do remarkably well in all of those situations. And not only for just a few minutes of the ride but fun for as long as you want. This is a crucial thing that for me differentiates a good gravel bike from a truly great one. Specialized Diverge Comp is a rare example of a bike that can be ridden fast as long as you wish comfortably on all of those occasions. Why? Because it beautifully combines all the necessary ingredients to do so…
Let’s start with the most beneficial one: Future Shock front suspension system. Prior to this test I have read and watched many reviews of this suspension system and to be honest none of them got me really excited. And this is a true shame because it is a very clever design that in my opinion is, in many ways, better than Redshift Suspension stem (which, as you may already know, I really like and use on my benchmark bike). Why exactly I think that Future Shock is better? It is all about the place where the suspension is doing all its magic. In terms of Redshift stem, it is on the pivot point between steerer and the stem itself. When you apply the force to the handlebar it flexes downwards. The longer the stem and the more weight you put on the handlebar (preferably on hoods or drops) the more it moves. And it has to move quite much to achieve good suspension results. So when riding on hoods you constantly feel the handlebar moving and if you want to mitigate the movement you need to use harder elastomers that will also greatly reduce the overall suspension effect. Future Shock in my test bike uses a spring suspension but the spring is placed in a direct line with a steerer and this makes all the difference. Why? Because it greatly reduces the handlebar movement when on hoods (you apply the force on hoods but it has to go first via stiff stem to the Future Shock spring). The placement of the suspension is also good for providing a similar level of comfort no matter where you put your hands (while the suspension stem form Redshift is least effective when riding on tops).
On my test bike, I had a Future Shock in its softest setup (there are also a middle and stiff one and you change it by changing the spring itself) and boy, it worked. I was deliberately looking for different test scenarios just to find limits to it. And I was constantly amazed how much suspension I can get from just a 2 cm of the Future Shock movement. One of my ultimate test of bike comfort is riding on a flood bank near the Vistula river. This is a very narrow path with a lot of imperfection both small and big. Normally I go there at 15 to 20 km/h. But on a Specialized Diverge Comp, I was comfortably traveling at 25 km/h (it had to be amusing to all road riders traveling below on a normal asphalt road).
Then there is a pure speed…
Specialized Diverge Comp is a carbon bike with a very massive PF30 bottom bracket area. Combine it with a short chainstay (421 mm) and you get a seriously fast bike. When I want to accelerate fast from standstill on my steel Jamis Renegade Exploit I usually end up with a speed of 43-45 km/h on a flat asphalt road. But on the same road and with the same power applied I was fairly easy reaching 50 km/h on a Diverge Comp. Seriously, I was amazed at how much quicker I can accelerate on this bike. It encourages you to go so fast that for the first time I started to think if a compact Praxis 48/32 crankset is enough to get the most of bike like this (yet in 99% situation I think it is).
For sure, part of the reason why this bike is so fast is a Specialized decision of using a modest 38 mm Specialized Pathfinder tires. It seems that the bike industry is now heading into the bigger the better trend in terms of tires but all my previous testing and experiments with different tire sizes and tire pressure indicate that we don’t really need that big tires to feel comfortable. It is all about finding the best combo between tire width and tire pressure. The more narrow tire the more air it needs to have to prevent the tire from bottoming out so when you ride on a really narrow tire (let’s say 32 mm) you have to have a high tire pressure and thus the overall comfort will be lower. But if you use tire like this 38 mm Pathfinder you can settle at 30 psi tire pressure and have low rolling resistance (thanks to narrow tire and a smooth thread) and at the same time a very comfortable ride without bottoming out on bigger ruts etc. When riding on Specialized Diverge Comp with those tire set up at 30 psi I was constantly thinking that I may found a perfect sweet spot between tire size, air pressure and tire thread (this tire has a rather supple casing, rolls well but also offers a surprising amount of grip when going off-road). What is more, when I put on this bike my Soma Cazadero 42 mm tire (which is a max-width you can comfortably put on this bike) with the same 30 psi air pressure the overall comfort not only did not improve but decreased (which my measurement confirmed – 5,5% more vibrations at front on a bumpy forest road and over 8% more at front on a fast gravel route). Only when I lowered the air pressure to something like 25 psi I was managed to achieve a similar amount of comfort. This is no surprise simply because a 42 mm tire at 30 psi has a lot more air in it which makes the tire more stiff (if you don’t believe me just do a simple experiment and try to squeeze a 38 mm and 42 mm tire both at 30 psi. You will quickly find that only after you lower the air pressure of 42 mm tire to something like 25 psi you will be able to squeeze both tires the same way). But 42 mm tire is wider so rolling resistance is bigger thus my thought that 38 mm may be indeed a sweet spot. At least for Specialized Diverge Comp.
Is this a holy grail of gravel bikes?
Close, but not really. First, there is the position that you get on this bike. Due to the Future Shock construction, this is a very tall bike (613 mm of a stack on my 56 size test bike). Combine this with a wide 44 cm Hoover Bar (with a 1,5 cm rise) and a very short chainstay and you got the sensation like you are sitting on a first and very old Bicykl (with a huge front wheel and a very tiny rear one). But to my surprise, this does not stop you from riding hard and fast on this bike and to be honest after a few minutes you simply adapt and forget about it. The high stack makes this bike also a great for longer trips but I for sure would change the handlebar for a more narrow 42 cm just to put my arms in a more comfortable position.
The second thing is… Future Shock. Or to be more exact, lack of the Future Shock 2.0 variant on 2020 Diverge bikes. I don’t know why Specialized did not put this on its gravel bikes (bikes that would, in my opinion, benefit the most from it) but the result is that you don’t get the possibility to adjust the suspension level simply by rotating the external dial. With Future Shock 2.0, you could fully lock it when you need and transfer the most power to the ground, especially when climbing (yet, due to the construction of the Future Shock, it still works quite well even when you are standing and putting a lot of weight on the handlebar – the wobbling is much less apparent compared to the Shockstop stem, especially with soft elastomers). Future Shock 2.0 is also a more refined suspension (it has a hydraulic damper) that works more smoothly (Future Shock 1.0, especially on its softest setting, is prone to bottoming out and you hear it which can be frustrating to some – for sure it is not a totally silent suspension like Shockstop stem and you can also feel it rattling during a hard braking).
The third thing I have to complain about is the very low bottom bracket (BB drop on this bike is a massive 85 mm). This results in a frequent pedal strokes even on not so bumpy roads. I know that this low BB combined with a short chainstay gives the super planted feeling but I think I would like to have a bike with a BB put a little further from the ground. And for sure I do not recommend putting 650x47b tires on this bike because your pedals will be destroyed by constant hits from the rocks, ruts, etc. Fortunately, you don’t need wider tires to feel comfortable on this bike and that’s the beauty of it!
And finally, there is a S-Works CG-R seatpost and Specialized Body Geometry Power Comp saddle. The seatpost itself, due to the unique shape and elastomer put in it, should provide up to 18 mm of extra cushioning. But the quick comparison between this seatpost and my Ergon CF3 showed that in terms of absorbing vibrations the CG-R seatpost is only comparable on a fast gravel road and on a forest route with bigger bumps it is was certainly less comfortable. The Power Comp saddle does not help either in that regard – in my saddle shootout it was offering much less compliance than a Brooks C17 or SQ Lab 612 Ergowave saddle. So, although the overall rear end comfort provided by the Diverge Comp with its CG-R Seatpost and Power Comp saddle was enough to keep me seated in almost any situation, there is certainly a room for improvement – when I put my Ergon CF3 and Brooks C17 saddle on this bike I managed to lower the overall vibrations level at the rear by 9,5% on forest bumpy road (although on a fast gravel route there was no real improvement).
Is there anything else worth noticing?
Yes, two things actually. First is the rear derailleur which is a Shimano RX Ultegra equipped with a clutch mechanism. Its role is to lower the number of chain slaps when riding hard on a bumpy road. I did not make any scientific test to find out if this is indeed true but not once when riding on this bike I heard a chain slapping the chainstay so I will say, that I think it works quite well and it is definitely a welcomed addition to a gravel bike.
The second thing is the wheelset. Specialized Diverge Comp uses DT Swiss R470 wheels that have only 24 spokes. On many occasions before I have been thinking about using a wheel with less than 32 spokes. But I was more into 28 spokes and definitely not as low as 24. There is quite a popular notion that the fewer spokes the more compliance the wheel will offer. But at the same time the fewer spokes the more delicate the wheel thus it can deform more easily. So I was very curious how these 24 spokes DT Swiss wheels will behave and to be honest I still have doubts. After my tests, the rear wheel was in a good shape but the front was moving from side to side. Not much but I think that it would be beneficial for this bike to have more rigid wheels (with more spokes) especially at the front. Why? This is the issue I already described when reviewing a suspension sestposts. Having something like Redshift Suspension stem or Specialized Future Shock at the front makes you go harder on a bumpy road. And yes, you are suspended but the wheel takes all the beating. So I would happily trade off some of the possible added compliance from 24 spokes wheel and got something more tough and dependable instead.
Would I buy it?
When I was riding Specialized Diverge Comp I was constantly asking myself the same questions: Why do we really need a steel bike? Why do I own a steel bike? Yes, it is a very comfortable bike due to the flexing nature of the steel but at the same time, a steel bike (like my Jamis Renegade Exploit) feels more like a touring bike next to a carbon Diverge. It is nowhere near as fast and thus, dare to say it, simply less fun to ride. And this magical comfort of a steel frame when compared to today’s carbon gravel bikes simply stops to amaze me anymore. I had to use Lauf Grit SL suspension fork and a Redshift suspension stem in one of the lightest setting and combine them with a Soma Cazadero 42 mm tires run at a 25 psi just to stay competitive (but only on a fast gravel route because slow bumpy forest road was still better managed by Diverge on a 38 mm tire run at 30 psi). And all of this at the cost of more handlebar movement compared to the Diverge with Future Shock suspension.
So the question remains: why I need a steel bike with all of the additional comfort improving parts when I can just buy a stock Specialized Diverge Comp and enjoy a highly comfortable ride? The only answer I can think of is that my two and a half years old son loves to ride with me and I simply can’t install my Romer Jockey child bike seat on a carbon seat tube of the Diverge. So it looks like for now, I am stuck with my steel bike…