Boardman SLR 8.9 review

Boardman has finally had to put up the price of its carbon fibre SLR 8.9 – but this has been accompanied by an upgrade to a mainly Shimano 105 groupset. And Boardman has also worked to improve the contact points.

Throw in a frameset with the same aerodynamic profiles as Boardman’s top-level 9.6 and the SLR 8.9’s 2021 iteration looks to offer the same impressive value as its predecessors.

Despite that price increase over the 2020 model, which we also rated, the SLR 8.9 is still one of the least expensive carbon road bikes you can buy right now, along with Vitus’s disc-braked, Tiagra-equipped Zenium.

What sets the SLR 8.9 apart from the Vitus, though, and most of the aluminium-framed bikes at this price, is that near-complete Shimano 105 groupset.

Boardman SLR 8.9 frame

Apart from a new colour scheme – adding a brightish blue to 2021's near-ubiquitous black – the frameset is unchanged from last year. But in addition to the headline move to 11-speed 105 from 10-speed Tiagra, there have been a few other less noticeable but mainly welcome changes.

Working with Chris Boardman and using experience gained from numerous bike-fits, as well as changing the saddle the designers have reduced crank length and handlebar width “to make sure they are suited to the needs of real cyclists, not just based on traditions”.

A further advantage is that this also reduces the frontal area slightly, reducing drag, although that's not a big concern for me on a bike like this.

The frame features all of today’s design cues, from its large-section, squared-off main tubes to its dropped, pencil-thin seatstays.

The former, developed in the wind tunnel, maximise stiffness, the latter contribute comfort aided by a decent length of exposed 27.2mm seatpost – unlike the 31.6mm Boardman uses on its ADV 8.9 – allowed by the semi-compact frame.

Boardman SLR 8.9 geometry

Boardman describes the geometry as endurance but I’ve always found it lives on the racier end of that spectrum, with a medium-length top tube and frame angles close to, or bang on, the race bike-classic parallel 73-degree frame angles, throughout the four-bike range.

The result is a ride that’s as fast as it’s comfortable, with impressively controlled handling from the front end’s stiff carbon fork and oversized, tapered steerer; the slightly narrower bar also adds more liveliness to the handling.

It descends very nimbly, and while the braking can’t compete with hydraulic discs, it never let me down.

Boardman SLR 8.9 kit

The SLR’s wheels are pretty basic but they’re tubeless-ready and paired with decent Vittoria 25mm tyres, even if the tyres major on grip and durability rather than feedback and feel.

They’re absolutely fine for the price but, especially with the bike’s upgrade to 11-speed 105, they’re ripe for upgrade to really make the most of the frame's quality.

I’d also go for wider 28mm tyres, the largest the frame and fork allow, once the Graphene-infused Vittoria Zaffiro Pro tyres have given their all.

When it came to swapping tyres, though, I did struggle to get them off of the wheels' rims. I managed it without squishing the tube, but had to pump up the tyre to the maximum pressure to get it to seat comfortably, and then release a little pressure.

Apart from the attention-grabbing 105, I was pleased to see the SLR’s cassette is now an 11-30 rather than the 11-28 on last year’s model.

Living in a very hilly area – even my commute has a short 11 per cent section – I'd always plump for an 11-32 or the 11-34 I have on my own road bike, but even two teeth helped me on over my challenging test routes. How about going the whole hog with an 11-34 next year, Boardman?

The only deviations from Shimano are the same as on last year’s bike – an FSA Gossamer chainset and Tektro R315 long-arm caliper brakes. And considering the bike’s price, I’ve no complaints.

Shifting across the front ring and braking are fine, even if the deep-drop Tektros don’t have quite the bite of the Shimano 105 equivalents.

The deep drops do allow mudguards to be fitted, though, and at least the calipers have cartridge blocks so you can experiment with different compounds.

Boardman SLR 8.9 bottom line

It’s a shame that Boardman bowed to the inevitable and upped the price, but this year’s model – like its predecessors – is very well worth the money.

There’s no doubt that the SLR offers one of the smoothest rides of any bike at this price – one of the advantages of carbon fibre, of course.

You never feel that you are wanting for any stiffness, and there’s little obvious flex when you’re out of the saddle and cranking up the gears, but with long rides over potholed roads you never feel battered – a compliment to the redesigned Boardman saddle and the frame.

The SLR 8.9’s geometry lends itself to sportives, fitness riding, training and commuting, and is simply bags of fun to ride.