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Prime has created a tough yet lightweight package with its Kanza 650B Carbon Gravel wheels. The wide rims make fitting larger tyres a breeze and they stand up to a lot of abuse on the trails. At under 1,600g they are responsive too, and you certainly can't complain about the price.
A lot of gravel bikes are coming with the smaller diameter 650B wheels these days, over the more standard 700C, or at least have framesets designed to work with them, and if you are looking for an upgrade then these Kanza wheels are a great place to start.
Wider tyres fit easily with the wheels' 32mm-wide rims (24.5mm internal), sitting with a nice rounded profile once installed.
I went with the excellent Rene Herse Juniper Ridge tyres in a 48mm width. As the Prime wheels come with tubeless tape already fitted and valves included, it's a pretty inexpensive way to get set up.
As you can see from that review, the Juniper Ridges aren't the easiest tyres to fit without using some kind of compressor to get the supple sidewalls to pop up against the rim edges, but once in place on the Kanzas the fit was fine and I had no issues whatsoever.
If you don't want to go tubeless, they work fine with an inner tube too.
Once fitted to the bike and out on the trails, the Kanzas felt nippy and responsive. Lighter gravel wheels can be had, but at 1,550g (730g front, 820g rear) for the pair, Prime has delivered on performance without sacrificing the durability.
They seem to pick up speed well and certainly don't give a feeling of getting bogged down when accelerating hard from a standing start or a slow speed. Stiffness levels are also high, with no feeling of flex when accelerating hard or climbing.
With 24 Pillar PDB 1415 double-butted spokes front and rear it's a strong build, and at the end of a month of testing the wheels are still looking and feeling pretty much like new.
At speed on my local gravel tracks I had a few 'moments' and whacked a couple of potholes which, because of the colour of the stones and the angles when descending, are near-impossible to see at times. The noises weren't good but the Kanzas took it all in their stride and it didn't affect their trueness either.
The hubs are CNC machined from 7075 aluminium alloy and look nicely finished, adding to the overall quality of the wheels.
The sealed cartridge bearings have seen plenty of grit, mud and water over the test period and are still running smoothly. I can't see any signs of water ingress either. Replacement bearings are readily available and cost around a tenner a wheel, so when they need replacing it isn't exactly going to break the bank.
The hubs come as 12mm thru-axle as standard, although there are various kits you can buy for quick release, and you get 15mm end caps in the box.
The freehub has an anti-bite guard which stops the Shimano cassette body from digging into the splines under heavy pedalling loads, which is a nice touch at this price. There is a SRAM XDR freehub available and one for Campagnolo too, but these are optional upgrades and don't come as standard built wheels; this will add around £25 to the price.
Even if you had to add that on top, though, the price is still very competitive with an rrp of just a penny shy of £600.
Mike absolutely loved the Hunt 35 Carbon Gravel Disc X-Wide wheelset and Hunt also does a 650B version. They have a shallower rim depth of 22mm compared to the 30mm of the Prime Kanzas, but are a similar width internally and a similar weight.
It isn't often that Hunt is beaten on price, but the Primes are £199 cheaper than the £799 asking price of the Hunts.
The Primes stand up well against the FFWD F3A Disc Brake wheelset, too, which cost £624.95. They're very good wheels in their own right, but for the money you are getting an alloy rim rather than a carbon one, and they're a little heftier.
Overall, when it comes to performance and build quality, I can't really fault the Kanzas, especially for the money.
Solidly built, with a great performance – top-level carbon wheelset at an entry-level price
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road.cc test report
Make and model: Prime Kanza 650B Carbon Gravel Wheelset
Size tested: 650B
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?
Chain Reaction Cycles says, "Sending you through forest pathways and gravel routes with ease, this Prime carbon 650b wheelset is a venturesome and versatile wheelset for the curious cyclist. Whether touring around town or taking the road less-travelled, the Kanza is sturdy and stiff, whatever the terrain. With a 32mm inner and 30mm deep rim profile, each wheel gives unbeatable balance on every journey."
They're very good gravel wheels that will take the abuse of off-road riding.
Tell us some more about the technical aspects of the wheel?
Thanks to a 650b carbon rim you'll have more room for wider tyres, meaning comfort, compliance, and cornering performance is improved, and with more tyre between the rim and the road, the wheel diameter when the tyre is fitted is similar to a standard 700c wheel and road tyre combo, meaning you won't lose out on speed.
Our new carbon fiber layup keeps the weight down, yet still maintains Prime's proven carbon rim durability. And, when paired with tubeless tyres, you have the option to run lower tyre pressures, to increase comfort and cornering grip and reduce the risk of pinch flats.
Paired with RD020 hubs and Pillar spokes to produce a stiff and responsive wheelset, they also come with removable end caps, making them compatible with QR's and thru-axles, including 12 and 15mm front thru-axles as well as 12x142mm rear thru-axles. A Prime XDR freehub is also available for those who want to run SRAM 10-42 cassettes.
Optimal Braking Performance
Disc brakes generate an incredible amount of stopping power, even in wet conditions, so you can fly over tarmac or gravel with confidence knowing that the Prime Kanza 650b Carbon Gravel Wheelset can handle it all.
4 spare spokes & nipples
15mm thru axle end caps
10 speed spacer
Note: QR conversion kits sold separately.
Front Drive Side: 265mm, Front Non-Drive Side: 264mm
Rear Drive Side: 264mm, Rear Non-Drive Side: 265mm
Front: 2x 6902 Sealed Cartridge Bearings
Rear: 2x 6902 Sealed Cartridge Bearings
Freehub: 2x 6902 Sealed Cartridge Bearings
Impressively stiff wheels when sprinting and climbing.
Did the wheels stay true? Any issues with spoke tension?
No issues with trueness or spoke tension at all.
How easy did you find it to fit tyres?
Various tyres fitted fine and tubeless tyres sealed well around the bead.
How did the wheel extras (eg skewers and rim tape) perform?
In the box you get tubeless valves, four spare spokes, 15mm end caps and a 10-speed spacer. Tubeless tape is already fitted. It's all decent quality stuff and does the job without issue.
Tell us how the wheel performed overall when used for its designed purpose
They consistently took plenty of abuse from the rough gravel tracks.
Tell us what you particularly liked about the wheel
Very durable for a reasonably lightweight set of wheels.
Tell us what you particularly disliked about the wheel
No SRAM XDR or Campagnolo options as standard.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
Very competitively priced. Up against something like the the excellent Hunt Carbon X-Wide wheelset mentioned in the review, the Primes still manage to come in nearly £200 cheaper, and they are a similar price to many alloy wheelsets like the FFWDs.
Did you enjoy using the wheel? Yes
Would you consider buying the wheel? Yes
Would you recommend the wheel to a friend? Yes
Use this box to explain your overall score
When it comes to how great they are to ride, the build quality and the weight, they can't really be faulted. The only downside is that if you need a SRAM XDR or Campagnolo freehub you have to purchase that as an extra.
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,
As part of the Tech Hub here at F-At Digital, our senior product reviewer Stu uses the knowledge gained from putting well over a 1,000 products through their paces (including hundreds of bikes) to write in-depth reviews of a huge range of kit. After first throwing his leg over a race bike back in 2000, Stu's ridden more than 160,000 miles on road, time-trial, track, and gravel bikes, and while he's put his racing days behind him he still likes to smash the pedals rather than take things easy. Although, as he spends a fair bit of his time reviewing ebikes these days he's becoming an expert in letting the motor take the strain. He's also waiting for 23mm race tyres to make a comeback!