The FSA Afterburner AGX disc wheelset is tough and durable, making it a very reliable option for off-road excursions and a bit of cyclo-cross action. You can get lighter and cheaper wheels, but this is definitely a set that puts your mind at rest.
The AGX wheels are based on an aluminium alloy rim that's 25mm deep with an external width of 26.1mm – suited to the wider tyres used for gravel and adventure riding. The 38mm tyres I used for the majority of testing fitted easily and sat with a nice profile once inflated.
Both rims, front and rear, have an offset spoke bed to accommodate the amount of dishing required for wide cassettes and disc brakes.
The rear wheel has the spoke holes offset towards the non-drive side, allowing for the drive side spokes to be laced at more of an angle between the hub and the rim, improving strength.
The front is offset to the opposite side to allow for the dishing caused by the disc rotor position.
Both wheels have 24 double butted aero spokes, laced two-cross. It's quite a low spoke count for a set of wheels designed to take plenty of abuse, but there were no issues whatsoever dealing with the rocky terrain of the local gravel tracks or hitting potholes on the road.
FSA has used brass nipples which is something I like to see on wheels that are likely to be used in all sorts of weather conditions. I've had alloy versions crack on me after a hard winter.
The rims were true straight out of the box and remained the same throughout testing. I didn't go out of my way to wreck them, but I took them to a couple of tracks that are really rough with sharp-edged rocks and deep holes for a bit of a kicking. Apart from a few horrible noises coming from some high-speed impacts there was no long-term damage.
Stiffness was also impressive, too, with hard efforts out of the saddle not seeing any issues with lateral flex.
At 1,789g (822g front, 967g rear) they aren't the lightest gravel wheels on the market but they don't actually feel that heavy. Acceleration and climbing were never a chore, and they were easy to spin up from a standing start over and over again.
Pawl engagement is quick and the sealed cartridge bearings run smoothly, with the wheels spinning happily in mid-air with barely any resistance.
The only thing I would like to see is a steel insert on the aluminium freehub as cassettes can dig into the slightly soft body under hard efforts. I've seen a lot worse, though, and even after two months of testing I had no issues sliding the cassette off the body and reassembling it.
The majority of brands have adopted Shimano's Centerlock for securing the rotors, which involves using something similar to a cassette lockring screwed into place to keep the rotor fixed to the wheel. It's quick and simple to use – much faster than the six-bolt system FSA has decided on here, which uses T25 Torx bolts.
As standard the wheels arrive set up for 12mm thru-axles front and rear, but there are adaptors available to convert the front hub to either 15mm thru-axle or quick release depending on your fork, and the rear to quick release if your frame isn't designed for thru-axles.
Value-wise, the Afterburner AGX will set you back £619.95 which, when shopping around, can look a little pricey. The package does include tubeless rim tape and tubeless valves.
Some of the best gravel wheels I've ridden are the JRA Geckos. Okay, they are carbon versus the alloy of the FSAs, but you do get a much lighter build for 'just' an extra £230.
JRA has an alloy wheelset for the road that it says is tough enough for cyclo-cross and the like, the MAP Road Disc which, in the same configuration as the Afterburners, will set you back about £371 and 1,581g.
When all's said and done, while there are cheaper and lighter options out there, if I was out for a long haul on the gravel – an epic adventure into the wilderness – I'd be happy to rely on the FSAs; I reckon they'd see you through it without putting a foot wrong. Sometimes that's worth a little bit more than saving a few quid.
Pricier and heavier than some, but a very reliable wheelset that can take plenty of abuse
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road.cc test report
Make and model: FSA Afterburner AGX wheelset
Size tested: 700C
Tell us what the wheel is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
The Afterburner AGX wheelset is available in two options, 650B and 700C, and is primarily designed for gravel use. I found them to be a solid build that stood up to a lot of abuse.
Tell us some more about the technical aspects of the wheel?
Asymmetric, 25mm depth x 26.1mm wide alloy rim
Available in 650B (27.5') and 700C (29')
Alloy P. R. A. hubs for direct pull spokes
ISO 6-Bolts rotor mount
Front hub with QR/TA-15 axle compatibility
Rear hub with QR/X-12 axle compatibility
2-cross double butted aero spokes with brass nipples
6-pawl aluminum for SMN 9-11 sp or SRAM XD 10-12 speed freehub
Artisan built, entirely by hand
Includes Alloy QR-65, tubeless valves (1 pair), FSA tubeless tape and spoke protector
Pricey at first glance, but over the years their durability should see that penny per mile drop considerably.
Did the wheels stay true? Any issues with spoke tension?
No problems at all.
How easy did you find it to fit tyres?
Very easy indeed, on and off, without the need for tyre levers.
How did the wheel extras (eg skewers and rim tape) perform?
The tubeless rim tape isn't the best I've used as it isn't that sticky and leaves a lot of air bubbles. It didn't affect performance though.
Tell us how the wheel performed overall when used for its designed purpose
They'll take all the gravel abuse you can throw at them.
Tell us what you particularly liked about the wheel
Tell us what you particularly disliked about the wheel
Steel inserts on the freehub for protection from the cassette would be good to see at this price.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
A lot of wheels of similar design are a fair bit cheaper, but the Afterburner AGX do offer good long-term benefits.
Did you enjoy using the wheel? Yes
Would you consider buying the wheel? Possibly, especially if they were discounted a bit.
Would you recommend the wheel to a friend? Yes
Use this box to explain your overall score
A good all-round performance from the FSAs goes some way to offsetting their slightly high price tag.
About the tester
I usually ride: This month's test bike My best bike is: B'Twin Ultra CF draped in the latest bling test components
I've been riding for: Over 20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, club rides, sportives, fixed/singlespeed
With 20 years of road cycling and over 150,000 miles in his legs it's safe to say Stu is happiest when on the bike whatever the weather. Since writing his first review for road.cc back in 2009 he has also had a career in engineering including 3D-CAD design and product development, so has a real passion for all of the latest technology coming through in the industry but is also a sucker for a classic steel frame, skinny tyres, rim brakes and a damn good paintjob.
His fascination with gravel bikes is getting out of control too!