The Prime RR-28s are good carbon fibre wheels for disc-equipped road, adventure and cyclocross bikes with a price that is significantly lower than many carbon clincher wheel alternatives.
Prime wheels are an in-house brand of Chain Reaction Cycles, and CRC's considerable buying power is why these wheels are so affordable compared to more well-known carbon wheel options.
In the Prime range there's a wide selection of rim and disc brake options with a choice of rim depths. The RR-28 carbon wheels here use the company's shallowest, 28mm deep, carbon rim. It's a good rim depth for a general purpose wheel for training or climbing, as the weight is kept down compared to the deeper section versions but you're still getting some aero advantage.
The rounded U-shape profile is in keeping with the latest aerodynamic designs being touted by the leading carbon fibre wheel specialists. Prime isn't making any aero claims with their wheels, and while aero performance is difficult to assess without a wind tunnel, they provided an impressively swift performance with good stability in windy conditions.
The rim measures 25mm on the outside and 16.5mm on the inside. That's good for tyres measuring 25 to 33mm according to Prime, meaning they can be used for everything from road bikes to cyclocross and possibly adventure bikes. But they're not as wide as rims like the ones Hunt use for the 30 Carbon Disc wheels which have a whopping 21.3mm internal width.
Narrow rims are fine with narrow tyres, of course, but the surge in popularity of wider tyres has been followed by an increase in rim width. With a wide tyre a wider rim can provide better aero performance but the bigger benefit is improved ride quality, as the extra width increases the tyre volume which leads to better comfort and handling.
I tested the wheels with 25mm tyres on a road bike and 33mm gravel tyres on an adventure bike. They worked well with both. There's a hint of a light bulb effect with the wider tyres, but ride performance was good without too much squirming at lower pressures. I found they worked best set up with a 25 or 28mm slick road tyre and proved a good upgrade to a disc road bike with heavier aluminium stock wheels.
I'm a tubeless fan and these rims are tubeless-ready, so I immediately took advantage of the opportunity to ditch the inner tubes. The tyres inflated at the first attempt using just a track pump and air retention was excellent, with no noticeable loss over an extended period. You can use regular clincher tyres as well, and I did with no fuss or drama.
The rims are made from T700 unidirectional carbon fibre with reasonably understated decals, certainly not as shouty as some wheel brands I could mention. They looked smart on every bike I fitted them to. The durability was without fault throughout testing, particularly when fitted to an adventure bike and taken off-road. They fended off impacts from rocks and roots well.
The rims are built up with 24 DT Swiss double butted spokes per wheel laced to Prime's own hubs with DT Swiss Pro Lock nipples. Said nipples are external so tweaking the spoke tension is an easy task, though it was unnecessary during my time with the wheels.
The hub bodies are forged and CNC-machined from 7075 aluminium and the rear hub has a Shimano and SRAM compatible four pawl freehub with 26 points of engagement, and an Anti Bite Guard (a steel strip) to stop hard steel sprocket splines from digging into the softer aluminium. Inside the hubs are Japanese sealed bearings (four front, two rear) and outside we find replaceable end caps; adapters for quick release or thru-axle bikes are included.
Many wheel makers are opting for Shimano's Center Lock rotor mount on new models, but Prime has used the six-bolt standard. That's fine as six-bolt rotors are readily available, and while you can get adapters to fit Center Lock rotors to 6 bolt hubs, it would be nice if Prime included some in case you're upgrading a disc bike with Center Lock rotors.
The wheels ran nicely throughout testing. The hubs were smooth and reliable, with the freehub offering razor sharp engagement and the bearings standing up to much wet weather riding and hose pipe bike washing.
Wheel stiffness impressed, with good lateral stiffness when pushing the bike hard into turns or cranking on the handlebars in a sprint or powering up steep climbs. Vertical stiffness is reasonable as well and they dealt with the imperfect roads round my way and certainly didn't feel harsh or provide too much feedback through the contact points in the way that some carbon deep section wheels can.
Apart from the slightly narrow rim design compared to more progressive options, the Prime wheels worked well. They're a decent weight, provide an aero advantage over box-section aluminium rims and are stable in high winds. The hubs are smooth and reliable and the tubeless compatibility works a treat.
Priced at a frankly unbelievable £625, they effortlessly undercut most other carbon disc wheel options but you're getting the reassurance of buying from a large company like CRC, so if anything goes wrong they'll look after you with a full warranty.
Carbon wheels are a big step up from aluminium in terms of price but if you've got your heart set on carbon these are a good option.
Fast, durable and tubeless carbon fibre wheels without a scary price tag
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road.cc test report
Make and model: Prime RR-28 Carbon Clincher Disc Road 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 RR-28 Carbon Clincher Disc Wheelset from Prime is the perfect wheelset for climbers and long distance riders alike; a shallow 28mm deep rim profile reduces rotational weight to help you climb faster and adds increased stability in crosswinds to provide predictable handling.
Our 25mm wide rim profile is optimised for use with wider tyres ranging from 25c to 33c. For road use 25c to 30c tyres can easily be accommodated with our preference swaying towards 25c for all round use.
The use of wider tyres offer many benefits; a wider contact patch for increased traction and cornering grip; reduced rolling resistance and added comfort associated with higher volume tyres.
For gravel and Cyclocross use tyres ranging from 28c to 33c will easily be accommodated.
The RR-28 features our CC-28 rims with RD020 hubset and is hand built with DT Swiss Double Butted spokes and DT Swiss Pro Lock nipples.
Tell us some more about the technical aspects of the wheel?
Prime Quick Release skewers
Adaptor kits for QR / 12mm / 15mm (Front) – QR / 12mm x 142mm (Rear)
Spare spokes x 3: 1 front, 2 x Rear (1 drive side / 1 non drive side)
Nipples x 3
Total Wheelset Weight: 1630g
Material: T700 UD carbon fibre rim section
Rim Profile: Prime U profile for enhanced aerodynamics and predictable handling in crosswinds
Spoke count: 24 hole
Rim width: 25mm wide (16.5mm internal rim width)
For disc brake use only
Material: Superlight Forged & CNC machined 7075 alloy hub body
Spoke type: J Bend
IS 6 Bolt disc standard
Bearings: Premium Japanese sealed cartridge bearings x 4
2 in 1 Axle: 130mm x QR with 142mm x 12mm thru axle adaptors included
Points of engagement: 26
Freehub Body: Light weight alloy with ABG (Anti Bite Guard), Shimano/SRAM 9/10/11 speed
Freehub Body Option: Campagnolo freehub body available for purchase separately
Hole count: 24
Material: Forged & CNC machined 7075 alloy hub body
Spoke type: J Bend
IS 6 Bolt disc standard
Bearings: Premium Japanese sealed cartridge bearings x 2
3 in 1 Axle: 100mm x 9mm QR with 12mm thru axle & 15mm thru axle adaptors included
Hole count: 24
A high level of finish that you'd expect on a much more expensive wheelset, there's nothing cheap looking about them at all.
Solid, dependable and fast carbon wheels provide an ideal balance of weight and aero performance.
I put them through a rigorous test with cyclocross and adventure tyres and the held up just fine being ridden on rough trails.
They're not the lightest carbon wheels but they're certainly not heavy, and likely a weight saving over some of the heavy stock aluminium wheels coming on many disc-equipped bikes.
While carbon wheels have gotten cheaper, these are some of the most affordable wheels we've yet seen, and you're buying from a reputable retailer with a full warranty which is a nice bit of peace of mind.
Did the wheels stay true? Any issues with spoke tension?
The wheels stayed true throughout the test.
How easy did you find it to fit tyres?
Tubed and tubeless tyres were fitted with ease - tubeless tyres inflated with just a track pump.
How did the wheel extras (eg skewers and rim tape) perform?
You get replaceable end caps to fit the wheels to a quick release or thru-axle bike.
Tell us how the wheel performed overall when used for its designed purpose
For road riding, training and climbing and even cyclocross or adventure riding, these surpassed expectations.
Tell us what you particularly liked about the wheel
Really good price (for tubeless) and easy tubeless.
Tell us what you particularly disliked about the wheel
Narrow rim width compared to more modern alternatives.
Did you enjoy using the wheel? Yes
Would you consider buying the wheel? Maybe
Would you recommend the wheel to a friend? Yes
Use this box to explain your score
In a market where you can easily spend £3,500 on a set of carbon fibre wheels, getting this level of performance and durability for under a grand backed from a reputable retailer is highly impressive.
About the tester
I usually ride: My best bike is:
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, touring, mtb,
David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.