Boardman SLR Endurance Disc 9.4 road bike – review

A disc-equipped endurance bike is hardly out of the ordinary - but the Boardman manages to stand out from the crowd

Not so long ago the Boardman SLR Endurance Disc 9.4 would have been considered to be the shape of things to come – a full-carbon endurance bike with hydraulic disc brakes and thru-axles.

But now, there are so many riders are looking for fast, light, comfortable bikes with braking performance that’s uncompromised by rim material or weather, that models like this are becoming commonplace. You could almost go so far as to say this is an example of the new normal. Except for the fact that it’s not completely normal.

Yes, it’s a £2.5-grand endurance bike; yes, it has a full-carbon frame; yes, it’s got hydraulic disc brakes; and yes, plenty of manufacturers have similar bikes. But precious few of them also come with Shimano’s electronic Ultegra Di2 groupset.

The Boardman SLR Endurance Disc 9.4 comes from the British brand’s Elite range

To put it into context, the nearest equivalent from Specialized, the £2,400 Roubaix Comp, has a carbon frame, hydraulic disc brakes and a small suspension system in the headtube. But the only Ultegra parts it comes with are the mechanical front and rear derailleurs. The rest of its groupset is made up of 105 bits and a Praxis crankset.

Trek’s Domane is another bike that features comfort-enhancing systems, this time in the form of Trek’s IsoSpeed decouplers at the front and back, but the £2,000 S5 Disc is 105 equipped and so is the £3,100 SL5 Disc.

  • Specification

  • Price: £2,599
  • Sizes: XXS-XXL
  • Size tested: XL
  • Website: Boardman Bikes

What about Cannondale? Well, its endurance bikes don’t have the elaborate suspension technology built in, so they should fare better on the price front. And, in fairness, the Synapse Carbon Disc Ultegra is a hundred quid cheaper than the Boardman and does come with hydraulic discs and – as the name suggests – an Ultegra groupset. But it’s mechanical Ultegra, not the electronic version.

As for Giant’s efforts, neither of them really come close on the spec front. The Defy Advanced Pro 1 costs £2,799 and has mechanical Ultegra, while the Defy Advance Pro 2 will set you back almost as much as much as the Boardman (£2,399) but comes with 105.

So given its price and spec, Boardman’s SLR Endurance Disc 9.4 makes an outstanding case for itself. But it’s not just the spec that works it this bike’s favour.

Striking the right balance

The 9.4’s frame is made from Boardman’s C10 carbon. It’s a mix of Toray T1000 and T800 fibres, the same as those used in the company’s top-of-the-line frames. “It’s the highest-performance carbon fibre we use,” explains Boardman’s Jamie Mitchell.

“It allows us to create the perfect balance between weight, stiffness and uncompromised ride feel. It means we can create a very stiff yet comfortable frame. It’s born of the same race heritage as the rest of the range but with slightly more seatstay compliance.”

Slim and supple seatstays are a mainstay of endurance bikes but they aren’t the whole story. The other key characteristic is a shorter, higher front-end, so that everyday riders don’t have induce back problems by trying to adopt the long and low position of replica race bikes.

Boardman SLR Endurance Disc 9.4 road bike - review (Pic: George Scott/Factory Media)
Boardman SLR Endurance Disc 9.4 road bike - review (Pic: George Scott/Factory Media)
Boardman SLR Endurance Disc 9.4 road bike - review (Pic: George Scott/Factory Media)

The problem is, when you combine a flexy rear-end with a front that’s taller and closer, it’s all too easy to end up with a bike that lacks the sort of spark necessary to inspire speed. It can end up feeling soft and blunt, as if you’re on more of a sit-up-and-beg bike rather than something intended for riding challenging landscapes, comfortably. There are ways to avoid this, however, and Boardman have sought to ensure the Endurance’s geometry strikes a balance between racy and comfortable.

“We wanted to keep the unrivaled performance that Boardman bikes are known for while still keeping the 9.4 comfortable for long hours in the saddle,” says Mitchell. “A lot of brands have gone too long with their headtubes to cater for a sportive market. But through research and customer feedback we think we’ve worked out the optimum headtube lengths for enhanced performance all year round.”   

The other thing that might be helping the 9.4 frame retain a racy feel while still being able to take the sting out of the road is the wheels it’s specced with. The bike runs on a pair of 22mm-wide Boardman SLR Five Disc wheels that have been paired with 25mm Vittoria Open Corsa tyres (although the frame can take tyres up to 28mm wide). It makes for a pretty beefy pairing that easily soaks up almost everything the tarmac can throw at it. And, chances are, having rims and rubber like this probably means the frame can be a bit stiffer, since some of its cushioning duties will be taken care of by the wheels.

With a 28mm rim depth, the wheels are ever-so-slightly profiled but probably not enough to satisfy the aero obsessives, especially as they’re each built with 28 round-gauge, straight-pull spokes. It is, however, a practical construction and should you find yourself with a broken one while you’re overseas, will be easy enough for any bike shop to replace.

Both wheels are held in place by thru-axles, a 15mm one at the front and a 12mm one at the back. They’re said to be safer than conventional quick-releases as they cope better with the breaking forces discs can generate (helped by the closed dropouts that keep the wheel in the bike). They’re also said to be stiffer but you’d need to have exquisitely calibrated senses to be able to discern any difference they make to handling.

The SLR Endurance Disc has been around for a little while now and the different diameter thru-axles used on the front and rear wheels is a minor irritation given that 12mm seems to have since become the norm for both on other disc-equipped endurance bikes – something that’s perhaps reflected in the Boardman’s competitive pricing compared to the latest competition. That said, the only problem you’re likely to run into with the 9.4’s 12mm/15mm set-up is a slightly limited choice of wheels if you want to upgrade in the future.

The rest of the bike’s finishing kit – the carbon seatpost, the carbon stem, the alloy bars and the bar tape -is all Boardman’s own, although the colour-coordinated saddle is a sleek and reassuringly firm Nago Evo from Prologo.

The frame bears the name of 1992 Olympic champion and three-time Tour de France stage winner Chris Boardman

The whole package

The case for the 9.4’s value may be overwhelming but price alone isn’t enough to make you desire a bike. For that you need a combination good looks, great handling and a promise of speed.

And the good news is that the handling and the speed are definitely there. As for the looks… well, those are a personal matter. You may love them; I’m not quite sold on the powder-blue head tube/pseudo-Sky colour scheme.

Complicating the aesthetics issue further are the disc brakes – the disc themselves look pretty cool but the effect the hydraulic system has on the hoods is not what you’d call elegant. Elephantine is a more accurate description, as creating space for the cylinders has meant the hoods have had to be extended upwards, giving them a swollen look that’s not dissimilar to the Mekon’s head.

The 9.4 was developed before Shimano launched its flat mount open standard for disc brakes, so instead of the calipers bolting flush onto the fork and frame, they’re attached to adapters that sit on posts. If you’re in the market for an endurance bike now, you may see that as a shortcoming but the post-mount calipers on the 9.4 are hardly an eyesore – compared to those hoods – and lack nothing on the performance front. And should you want to swap or upgrade the brakes you’re unlikely to struggle to find suitable adapters for a few years yet, so it’s nothing you need worry about.

But would I be prepared to overlook those factors if I was in the market for a bike like this? Absolutely, because the 9.4 is a lovely bike to ride.

The hours fly by while you’re in the saddle and the only discomfort you feel is the fatigue building in your legs and lungs from pedalling. Meanwhile, your back and backside are both enjoying a proverbial and literal easy ride.

Endurance bikes, generally speaking, leave me a little cold as they can lack the sort of stiffness you get with a race bike and tend to be springy rather than sprightly. But the 9.4 gets the balance between the two just right. It feels like it reacts instantly, unlike some endurance bikes that seem to pause for a moment so tension can build up sufficiently before being released.

Boardman SLR Endurance Disc 9.4 road bike - review (Pic: George Scott/Factory Media)
Boardman SLR Endurance Disc 9.4 road bike - review (Pic: George Scott/Factory Media)

The 9.4 is quick and nimble, in other words, and a lot of fun to fling about. But it’s not totally gripe free. The compact 50-34t chainset makes total sense for an endurance bike that’s likely to encounter a lot very big hills, but if your local landscape is rolling, or only a little lumpy, you tend to feel somewhat under-geared. Still, that’s a personal gripe, though a semi-compact chainset would be a better fit the bike.

As for the shifting, do electronic gears help you ride better? No, not especially. But they certainly don’t hurt and the novelty of the Robocop-sounding buzz that accompanies the shifting never seems to wear off. Could you live without electronic gears? Yes, absolutely. Are there any downsides to them? Well, the main shift blade is fine but the inner button is a bit narrow and can be tricky to press accurately if you’re wearing thick gloves. But, aside from that, not really. And they’re a nice addition to have and give you fast, accurate shifting, so why quibble when they’re thrown into the bargain along with the disc brakes.


What we have here is a typical Boardman bike: a lively, responsive machine that’s well-specced and good value for money. There are aspects that won’t be to everyone’s taste and it doesn’t have all the very latest tech, but there’s nothing you can really complain about. All in all, as much as the Boardman SLR Endurance Disc 9.4 may represent the new normal, it still manages to be stand out from the crowd.


  • Well-balanced fame; stiff and comfortable with a sensible geometry
  • Compact chainset for going uphill
  • Excellent spec; good value for money


  • Compact chainset not ideal for flat or mildly lumpy terrain
  • Big-headed hoods
  • Main shifter blades ok but inner buttons too narrow


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