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Boardman SLR 9.4 AXS Disc Carbon review

Boardman's SLR 9.4 AXS Disc Carbon is crowned our 2021 Road Bike of the Year winner

Our rating 
5.0 out of 5 star rating 5.0
GBP £2,700.00 RRP
Pack shot of the Boardman SLR 9.4 AXS Disc Carbon - BikeRadar BOTY 2021

Our review

The SLR is a firm favourite, and the addition of a cutting-edge wireless drivetrain and lightweight frameset for far less than ever before have only improved things
Pros: Excellent chassis; superb drivetrain; big value package
Cons: Skinny bar tape; average saddle
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Boardman Bikes may only be in its teenage years but, since its 2007 birth, its British-designed bikes have gained massive popularity for riders of all disciplines and at every price point. Nicole Cooke powered a Boardman bike to Olympic victory in 2008 and Boardman-riding cyclists have racked up numerous titles on the road, off-road and in triathlons.

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We’ve long been fans of Boardman’s SLR range, and with SRAM’s new wireless 12-speed Rival groupset and a lighter weight frame adding to its all-round stunning performance, the Boardman SLR 9.4 AXS Disc Carbon has taken the top spot in our coveted Road Bike of the Year test, beating 20 other bikes from five categories: endurance, performance, gravel, superbike and £1,000.

Boardman SLR 9.4 AXS Disc Carbon frame

As with many of its rivals, the SLR 9.4 was designed to provide genuine aerodynamic advantages, but it’s also an endurance bike in the manner of Sensa’s Giulia and Cervélo’s Caledonia 5 – also contenders in this year’s Bike of the Year.

The chassis successfully mixes aerodynamics and long-distance comfort while adding hidden mudguard mounts and generous tyre clearances for the British riding experience.

Up until this year, Boardman’s top-specification C10 carbon was reserved for its premium models, but for 2021 C10 has trickled down to the 9.4. This results in a sub-900g frame and very light 350g fork: weights approaching those of a superbike.

The SLR 9.4’s main frame tubes have kammtail truncated airfoil profiles – think of a cross-section of an aircraft wing with the tail of the teardrop shape cut-off, to give the aerodynamic benefit of an airfoil but without the extra weight.

Further racy features include the dedicated aero-shaped carbon seatpost, which comes with 20mm offset – but, you can flip the seatclamp to zero offset, effectively steepening the seat-tube angle for a racier position. A nod to Mr Boardman? Maybe.

And with the clamp flipped and tri-bars fitted, you could easily tackle a time trial or triathlon.

Boardman SLR 9.4 AXS Disc Carbon ride impressions

Pack shot of the Boardman SLR 9.4 AXS Disc Carbon - BikeRadar BOTY 2021
The new SLR frame was developed and tested in the wind tunnel.
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This size large bike is effectively a 57cm and its geometry, with a wheelbase that measures 1,006mm for a trail figure of 58mm with 28mm tyres fitted, delivers a ride that’s stable at high speeds but with a steering response quick enough to keep things exciting when pushing your limits into a corner or on a fast descent.

The SLR has a relatively low stack (584mm) for an endurance bike, which lets you get down into quite a sporty position on the shallow drops, even if the reach (391mm) is a little shorter than a race bike would be.

If you want to go lower still, a new stem would let you adjust your fit.

While much of the SLR’s brilliantly balanced ride is down to the lightweight chassis, some credit has to go to Alexrim’s RXD3 wheels.

These may not be a premium name, but the 30mm deep aero-shaped alloy rims are tubeless-ready and their 19mm internal width is well suited to the 28mm tyres.

They’re very light for aluminium at 1,550g a pair, pick up speed smoothly and combine with the wide rubber to blend lateral rigidity with compliance.

Vittoria’s middleweight Rubino tyres are tough with their graphene compound, and their all-weather performance is better than any previous Rubino, gripping well in the wet and dry.

However, I’d switch them out later for something faster and lighter – and tubeless – but they don’t spoil the party.

While the ride quality is good generally, the back end is slightly more compliant than the front, which is probably down to the rather squishy padded saddle contrasting with the stiff alloy bar at the front end more than anything else.

The spring-loaded rear mech clutch meant the chain stayed planted without bouncing or dropping on really rough roads.

Boardman SLR 9.4 AXS Disc Carbon geometry

Seat angle (degrees)7473.573.57373
Head angle (degrees)717272.57373
Chainstay (cm)41.541.541.541.541.5
Seat tube (cm)4748.55052.554.5
Top tube (cm)52.55455.55758.5
Head tube (cm)1214161819.5
Fork offset (cm)
Bottom bracket drop (cm)
Wheelbase (mm)9919931,0021,0061,022
Stack (cm)51.754.256.358.460
Reach (cm)37.73838.839.140.2

Wireless performance

Boardman and SRAM have had a long relationship, and SRAM has partnered with Boardman for the launch of its Rival 12-speed eTap AXS groupset.

Wireless AXS has only previously been available as part of SRAM’s RED and Force groupsets. The new Rival AXS has the same motors, circuits, antennae and electronics as its pricier siblings but ditches carbon for aluminium, offering the same performance with just a small weight penalty (around 300g over the much more expensive Force AXS).

On the road, this means the same functionality: the right button shifts to a higher gear, the left to an easier gear; click both together and the front derailleur shifts.

It’s intuitive, precise, a match for Force and on a par with Ultegra Di2 – and less expensive than both.

You can pair AXS with its free app to adjust settings, such as the number of multi-shifts from a prolonged button press or choose compensation mode so that when you shift the front mech it automatically shifts the rear gears to compensate and puts you in the next best available gear to keep your pedalling smooth.

You can also go full-auto shift for the front mech, which means as you shift up or down the rear block the bike will automatically change the front mech to the next best gear when you’re reaching the extremes at either end of the 12 speeds.

AXS will also sync with a Garmin head unit, where it will display gear selected, battery levels and multiple other metrics.

SRAM achieves the 12-speed arrangement smartly, with a 10-30 cassette and 46/33 chainset that translates to a bigger gear for speed and a lighter climbing gear. A win-win.

That 10-30 cassette also means the first six gears all run with single tooth jumps, compared to an 11-speed equivalent (11-28) that only has single-tooth jumps for five gears from 11 to 15.

It’s very clever stuff and a proper taste of the future of gearing. I’ve been running Force AXS on one of my own bikes for more than a couple of years now and have had zero issues. I’ve not needed to make any adjustments once set up and maintenance has involved cleaning and lubricating the chain, beyond ensuring the batteries are charged.

The SRAM Rival brakes performed brilliantly too, and I found it hard to distinguish them from Force’s hydraulics. However, to keep costs down the Rival levers lack the contact point adjustment of Force, but they do retain reach adjust.

This also means that the Rival hood is slightly narrower than its more expensive sibling, which is arguably a better fit for smaller hands.

Using Rival AXS makes me feel like someone who has managed to get a Ferrari-like performance on Ford money.

Boardman SLR 9.4 AXS Disc Carbon bottom line

I was so impressed by Boardman’s SLR 9.4. It’s a bike that has everything going for it – a lightweight aero frameset, futuristic wireless shifting, great drivetrain with smart gearing, good wheels and competent tyres.

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I’d consider changing the handlebar later on and using plusher bar tape but – considering the price – those are minor matters. And for its all-round ride, comfort, performance and high-tech components this Boardman nabs our Bike of the Year title for 2021.

Thanks to…

A massive thank-you to Q36.5 for sorting the kit for the photo and video shoots, Lazer for keeping our heads protected, and 100% for shielding our eyes from the elements on the roads and trails.

And not forgetting Muc-Off, for its help keeping the bikes washed and lubed throughout testing.

Road Bike of the Year 2021 contenders

Thirty-two of the best bikes ridden and rated…

  • ARC8 Escapee
  • Basso Venta 105 Disc
  • BMC Roadmachine TWO
  • BMC Teammachine SLR TWO
  • Boardman ADV 8.9
  • Boardman ADV 9.0
  • Boardman SLR 8.9 105
  • Boardman SLR 9.4 AXS (winner)
  • Cannondale SuperSix EVO
  • Cannondale Topstone Lefty 1
  • Cervélo Caledonia-5
  • Cinelli King Zydeco
  • Genesis CDA 30
  • Giant Contend AR 3
  • Giant TCR Advanced Pro 1
  • Giant TCR Advanced SL 0 Disc
  • Lapierre Xelius SL 5.0
  • Orbea Avant H60-D
  • Orbea Orca M20
  • Pearson Off Grid
  • Planet X London Road SRAM Apex 1 Disc
  • Ribble CGR Ti Pro
  • Ribble Endurance 725 Base
  • Ribble Endurance Ti
  • Rondo HVRT CF1
  • Sensa Giulia GF
  • Specialized Roubaix Sport
  • Specialized S-Works Aethos
  • Specialized S-Works Tarmac SL7
  • Trek Domane AL 5
  • Van Rysel EDR AF
  • Vitus Zenium Tiagra

Product Specifications


Price br_price, 5, 3, Price, GBP £2700.00
Weight br_weight, 5, 6, Weight, 8.01kg (L), Array, kg
Brand br_brand, 5, 10, Brand, Boardman


Available sizes br_availableSizes, 11, 0, Available sizes, XS, S, M, L, XL
Brakes br_brakes, 11, 0, Brakes, SRAM Rival hydraulic disc
Cassette br_cassette, 11, 0, Cassette, SRAM Rival eTap AXS - 10-30t
Chain br_chain, 11, 0, Chain, SRAM Rival 12 Speed
Cranks br_cranks, 11, 0, Cranks, SRAM Rival 46/33t
Fork br_fork, 11, 0, Fork, Carbon
Frame br_frame, 11, 0, Frame, Carbon
Handlebar br_handlebar, 11, 0, Handlebar, Boardman Elite alloy
Rear derailleur br_rearDerailleur, 11, 0, Rear derailleur, RAM Rival eTap AXS
Saddle br_saddle, 11, 0, Saddle, Boardman SLR
Seatpost br_seatpost, 11, 0, Seatpost, Boardman SLR Carbon
Shifter br_shifter, 11, 0, Shifter, RAM Rival eTap AXS
Stem br_stem, 11, 0, Stem, Boardman Elite alloy
Tyres br_tyres, 11, 0, Tyres, Vittoria Rubino Pro Graphene 2.0 28mm
Wheels br_wheels, 11, 0, Wheels, Alexrims RXD3 30mm