The Specialized Roubaix SL4 tested, rated and reviewed

Specialized Roubaix SL4Specialized Roubaix SL4


Arguably the Specialized Roubaix kicked off the whole ‘comfortable race bike’ genre. With unique (and slightly odd-looking) vibration-damping inserts in the fork blades and seatstays, the Roubaix was designed for racing on the eponymous cobbles – Tom Boonen won Paris-Roubaix on one. Away from pro bike racing, the Roubaix range appeals to sportivists and anyone putting in long rides at a decent clip.

Frame and fork

While all the frames in the Roubaix range look the same, they differ in grades of carbon. Don’t be fooled into thinking that you’re getting the same state-of-the-art frame as the top-of-the-range model, though. The one found on this entry-level bike is inevitably the heaviest, but the overall bike weight is 9kg on the nose so ‘heaviest’ isn’t actually all that heavy.

The Roubaix’s unique selling point is the Zertz technology. The Zertz inserts are viscoelastic pieces in pockets in the frame, which act to dampen vibrations from the road surface before they reach the bars and saddle. It’s not suspension – you can’t see anything moving – but there’s very little weight penalty.

You’ll find Zertz inserts in the fork, too, which also has an interesting take on the now-ubiquitous tapered steerer. The Roubaix fork is 1.125in at the top and 1.375in at the bottom, rather than the usual 1.5in. The idea is to add stiffness over a straight steerer without adding too much weight, though the downside is limited headset choice.

The fork is plugged into a head-tube that Specialized describe as “hyperbolic”, although they mean it in the geometric sense rather than the exaggerated sense (although some might argue otherwise). The tube has a double curve on the outside surface, with the goal of adding material where it’s needed for stiffness and losing it everywhere else.

The kit

Clearly a large proportion of the asking price is tied up in the frame. We’d expect at least Shimano Tiagra (or equivalent) at this price, and some bikes manage to get 105 on there for the money. But the Roubaix can only muster an 18-speed Sora transmission. Not that there’s anything very much wrong with Sora in its latest incarnation. The previous generation had an occasionally awkward lever/trigger set-up but the entry-level group now has the same double-lever shift arrangement as its more expensive brothers, and it’s pretty slick in action. You have to put up with exposed gear cables, although the lever-mounted barrel adjusters are useful.

We weren’t all that impressed by the Axis brakes, which work in a slightly grudging fashion, although better brake pads when the stock ones wear out would help considerably. The wheels are Specialized’s own Axis units shod with 25mm Espoir tyres. These feature a double layer of puncture protection, potentially useful for winter roads although there is a weight penalty.

There’s a fairly spectacular gear range, with the compact chainset up front driving a mountain bike-style 11-32 cassette. It’s arguable whether most people need that much range – it’s difficult to imagine that a rider who feels the need for 34/32 is going to get much use out of 50/11. It’s a big range to get out of a nine-speed cassette, too, giving significant gaps between gears that make it harder to maintain an even cadence on undulating roads.

The ride

While the Roubaix is marketed on the back of its undoubted race heritage, comfort is its big thing. The combination of 25mm tyres, the Zertz inserts, gel pads under the bar tape and a 27.2mm carbon seatpost means that the Roubaix scores highly on ride quality. It really is very smooth.

The geometry is fairly long and relaxed. The handling leans slightly towards stability over agility, which is sensible for a bike that lends itself to long rides. It’s tall at the front, too, with a particularly long head-tube – it’s very user-friendly if you’re still getting used to drop bars or aren’t that flexible, but the head-tube limits how low you can get the bars.

The Roubaix is a competitive weight, but you don’t get the alacrity of some of the competition. Somewhere between the high front end, sturdy tyres and slightly gappy gears some of your impetus gets lost. Whether that matters is rather subjective – the Roubaix is more about rolling along comfortably than charging ahead and lends itself to long rides of the sort that make sprinting performance a little moot, and deliberately so.

+ Wacky-looking Zertz inserts really do smooth out the ride
+ Relaxed geometry works well for long rides

– Underwhelming component spec for the money
– Wide-range gear set-up feels gappy on the road

 Specialized Roubaix SL4