Specialized Diverge 4 Sport and Terra CLX III Wheels

If you’ve seen Part I of this series, you know that I have gotten quite gravel-curious over the winter. It was a much-needed palette cleanser for the tired body and mind. The riding got a little stale, and a niggling elbow injury made rough rides a multi-day recovery affair. It turns out bikes are really great, and no matter what surface they are rolling on, there is satisfaction and fulfillment to be gained from the process of tiring legs and expanding lungs. My fitness wanders, especially during the winter months. I find myself often choosing rest over long bike rides, too. I wanted to lower the threshold of “yes!” to bike rides. If mountain bikes weren’t gonna do it, it had to be something else.

The problem is I am not as open-minded as I claim to be. Stuck in my ways, I built a significantly less capable version of a mountain bike with my Stigmata. It sure is pretty and plenty comfortable for commuting to the bike shop a couple of times a week. With 780mm wide bars and a dropper post, it is hella fun on a local segment called the “Escape from Bear Island.” It’s a flat-cornered, champagne gravel and moss covered twisty piece of heaven. It’s a place where you want to go extra slowly and stop every few meters to observe the stunning landscape and the abundant ecological wonders. But it is also a place where the Stiggy comes to life and just about out corners any conventional gravel bike setup. The problem with a bike that is excellent on that segment is that it is less so on the rest of the ride. Different-shaped bars had to enter my life. While the overall fit of the bike was adequate, the little voice in me that sounded awfully close to Cooper’s told me it was time for curly bars. The dark side was calling.

Specialized Diverge 4 Sport Carbon

The Diverge 4 comes in a few different dresses. There was a reason I picked the Sport Carbon. First of all, I wanted the Carbon frame. While there are diehard metal fans, I am not one of them. At least not for aluminum. I wanted a wide-range cassette with this bike. The 10-51t afforded by the Shimano drivetrain seemed like the only option. I also wanted a battery-free bicycle. If touring and bikepacking were to happen, I wanted to be detached from walls if possible. The sport carbon is a reasonably priced (3500 EUR // CAD // USD), mechanical GRX-driven, alloy-wheeled spec. that makes the most sense for the people. Higher-end builds of the Comp, Expert and Pro are a mix of Shimano GRX Di2 and SRAM Apex, Rival and Force AXS groups. There is even a Pro LTD model with a Shimano XTR Di2/GRX and Roval Terra CLX III option.

On the other end of the spectrum, you can jump onto a Diverge 4 Sport Alloy for 2400 EUR with Shimano Cues 11sp drivetrain. There is much happiness to be found on the lower end of the gravel bikes these days, where cables and sensible mechanics are lurking.

What I would love to see in the mid-range gravel sector would be a mechanical T-Type setup; Eagle 90 operated by mechanical brifters. I hope SRAM is listening.

Sizing

You should ask an expert for an opinion on road and gravel bike sizing. This expert might be a local bike shop, a local bike fitter or at least someone you trust. An ill-fitting bike will do a great job of destroying your knees and back, and erase any joy from cycling in general. Take this as a PSA and get the correctly sized bike. Specialized has a pretty good size calculator on their website. You enter your height and shin length to arrive at a suggested frame size. For my 175cm height and 43cm shins, I landed on a size 54 bike as I expected. This calculator does not take into consideration your arm and torso length. So if your length comes mainly from your upper body, start with a longer bike or longer stem for your fit. If you are mostly legs, a smaller bike might work with a shorter stem. There are limitations to how far you can raise or lower a seatpost, so ask an expert.

Wheels Matter

The Diverge 4 Sport Carbon comes with very decent, somewhat heavy ,DT Swiss G540 Wheels and Specialized hubs. The rims are 24mm internal width and are perfectly suited to the Diverge’s intentions. They are comfortable, tubeless and can rock the 45mm Tracer tires all day long. However, I do have an affinity for nicer wheels. Without soliciting, Specialized also sent a set of Roval Terra CLX III carbon wheels to go with this bike. Now, these are some pricy wheels. They roughly cost the same as the Diverge 4 Sport Carbon itself at 3100 EUR // CAD // USD

The Terra CLX III is one of the nicest and lightest gravel wheels on the market. Based on DT Swiss 180 EXP hubs, the carbon spokes by ARRIS and flat top Roval rims have a 27mm internal width suitable for the latest gravel race tires on the market. Impressively, these wheeIs weigh a little over 1000 g. I mounted the stock 45mm Specialized Tracer tires on the front and the optional fast-rolling Pathfinder on the rear. This makes for an incredibly light wheel to spool up on the budget Diverge Sport Carbon. For me, this combination of Carbon frame and wheels dressed up in sensible components makes the best sense. Would I spend my own dollars on these extremely pricy wheels? Hard to say at this point, as the Reserve 40|44 GR on the Stigmata are really good for a lot less money. I am hoping to run these wheels back-to-back for some real-world tests with a power meter.

The Future is Shocking

When it first showed its face on the Roubaix frame almost a decade ago, the Future Shock was a controversial piece of engineering. It turns the simple and unassuming stem/steerer interface into a 20 mm stroke, hydraulically damped (3.2 and 3.3), tunable(internal and/or external) suspension. There are plenty of claims around this rider aid. In basic terms, it isolates the rider’s upper body from the forces the front wheel is dealing with on rough surfaces. The Graveleur has options these days. Fox, Rockshox, Cane Creek and Lauf all have rather traditional devices to move the front wheel during an impact. These forks cost around a thousand in most of the currencies. While they work really well, the forks are heavier than carbon forks alone and require service. Some of them also have limited tire clearance for the modern gravel tire sizes.

Specialized chose to move the rider’s hands and upper body instead. The Sport Carbon Diverge has a lower price, with a less adjustable Future Shock 3.1 on the front.

The 3.1 has three spring rates to choose from, plus preload shims. The 3.2 adds hydraulic damping to control the rebound, while the 3.3 adds an externally adjustable lock-out dial. All Diverge bikes have a box of spare parts and extra springs to tune for rider weight. I left the stock medium-weight spring in there for the time being.

I was quite skeptical about my hands moving up and down with the bars, but it literally took minutes to get used to it on the road. While I sometimes wish for a lockout for on-road sections while I am out of the saddle climbing, I have no issues with the system as a whole. Ask me again in 6 months after many dusty and wet rides. The rubber boot that seals the system seems well-made and replaceable.

HERE is a link to the service manual for online reference. It might come in handy for people searching online.

Drivetrain

The drivetrain is an interesting element of the Sport Carbon Diverge 4. I am personally a big fan of the GRX shifter ergonomics. I find the reach adjustment on the GRX ST-RX610 levers to have decent range. I have been running them halfway in, and the tops of the hoods are fairly flat. There is a mix of parts from Shimano on the Diverge Sport. The Cassette is a 7100 series SLX cassette*, which is heavy and probably sacriligious to put on the Roval Wheelset. The rear derailleur is a GRX RX822 capable of a 1×12 wide range cassette. The Chain is also an SLX 7100. Cranks and 40T chainring are GRX RX610 as well and work well with the BSA bottom bracket on the Diverge. There is plenty of climbing gear range on the Diverge. Compared to the Stigmata that is running a 40T 11-46T combo, the 40T 10-51T is both faster on the flats and easier on the climbs. 172.5mm cranks are not in touch with current trends for a size 54 bike. I was expecting 170 or 165. I have a fixed-gear urban riding background, and I pedal through corners a lot. I have come close to striking a pedal on a few turns on my commute.

*The new Deore 12sp absorbs the SLX. This cassette remains with a new number (7200) associated with it.

Unfortunately, the Diverge breaks my “no bikes without dropper post” rule. The carbon seatpost is fine; it is comfortable and has built-in flex. In everyday practicality, the no dropper has not been an issue. But sometimes at stoplights and the aforementioned Escape from Bear Island, it would be welcome. The Diverge will get plenty of use this year. I will commute on it and I hope to take it on a few longer trips. There are some plans to explore some cargo options if things line up. The fit is good, and the ride is comfortable. There is enough clearance for some really wide tires, and I hope to explore that too.

I am looking forward to as many miles as possible with the Diverge in the next while. We’ll see if it’s a keeper or misses the mark for what I am after. I am very optimistic so far.

SPECIALIZED DIVERGE 4 3499 USD // CAD // EUR