Prime has discontinued these wheels. The successor is the Prime RR-38 V2. While I haven’t evaluated the RR-38, there doesn’t appear to be much different about the successors that would suggest a significant change in performance from those I’ve reviewed below.

The following review is part of the post BEST CARBON CLINCHER WHEELS

When the Prime line of carbon and alloy wheelsets for rim and disc brake bikes in shallow through aero depths were introduced in the summer of 2016, it got my attention.  I don’t remember such a wide range of products becoming available from a new brand all at once before.  The designs looked current, the prices were lower than the better-known wheelsets with similar specs, and the line was created and offered by Chain Reaction Cycles, the large UK retailer with some of the highest customer satisfaction ratings of any online bike store.  I ordered a set of the Prime RP-38 carbon rim brake wheels reviewed here and the RP-28 carbon disc brake wheels to evaluate for that post.

prime-rp-38Overall, I found the RP-38 wheels to be a capable set of carbon wheels.  They aren’t at the same overall performance level as the Best Value Reynolds Assault SLG (Competitive Cyclist, Tredz ITKTDZ10) that will cost you about 300 $, £, or € more or the Best Alternative carbon-alloy Shimano Dura Ace C35 CL (Competitive Cyclist) that will cost about 200 more than these RP-38s.  But, if you are on a tight budget and want a modern set of all carbon wheels and don’t care that they won’t be among the fastest in the bunch, these Primes provide you a good option.

They climb well, feeling both stiff and light and provide good feedback when going hard uphill or on the flats.  Both Nate, my super-fast and aggressive, occasional crit-racing friend who also tested these wheels, and me, a more modest B class group rider, found their stiffness performance somewhat surprising given their price.

Going downhill and on the flats in both dry and wet conditions the RP-38 braking is on par with other carbon wheels like the first generation ENVE and current Zipp Firecrest which have smooth brake tracks like these do.  They brake a bit quieter than others like the Assaults and clearly better than the more expensive Bontrager Aeolus 3 D3 or Easton EC90 SL.  The modulation and overall braking power of the newest models of wheels with textured brake tracks from ENVE and Zipp are a level above, but you will certainly brake well on these.

The RP-38 also handles responsively – move when and where you want them to – but felt a little less glued to the pavement than most other all-rounders I’ve tested.  I’m a light rider and they felt a little skittish to me when navigating through a group or handling on less than optimum road surfaces.

I tried two high performing tires on these wheels to try to find the right combination of speed (aerodynamics and rolling resistance), comfort and handling.  I first ran the 23C Zipp Tangente Course and then after a few weeks switched to the 23C Continental Grand Prix 4000S II.  Mounted and inflated, the Zipp tires measured approximately 23.5mm wide and the Conti’s just a touch wider than the 25mm width of the rims.

Neither set of tires on the RP-38 wheels felt very fast in getting up to or holding speed or very compliant, aka comfortable, when compared with the Assaults, C35s and other all-around wheels I’ve tested with the same 23C Contis.  Nate, who doesn’t seem to care much about comfort judging from his ride reports, summed up the speed experience charging across the flats or letting loose downhill on these wheels with the word “uninspiring”, disappointed that a 38mm deep wheelset performed more like 25mm alloys than 40mm carbon ones.


Prime recommends using 25C tires for all around riding on these wheels whose rims are made for them by Chinese producer Alex Rims.  On the RP-28 carbon road disc clinchers which run essentially the same 16.75 front to 16.9 rear inside and 25.0 mm outside widths as the RP-38s, I mounted 25C Conti GP4KSII that measured 27.3mm wide and 25C Schwalbe Pro One tubeless that ran 26.7mm to see how different they might ride.  Both 25C tires now exceeded the 25mm width of the rounded V-profile rims, defeating the potential aero benefit and didn’t seem to ride any faster, albeit on the shallower rims.

I also didn’t find the 25C Contis inflated at 80-85psi a whole lot more comfortable than the 23Cs at about 90psi.  It wasn’t until I ran the Schwalbe tubeless at about 75-80psi that I enjoyed a comfortable ride similar to using 23C Conti clinchers on other all-arounds I’ve reviewed.

The Novatec hubs used on these RP-38 wheels aren’t as responsive or quiet as some of the better hubs but aren’t slow or loud either.  Riding these wheels back to back on the same course on the same day as the Assaults, it was clear the DT240 hub used in the Assault and a number of other higher priced carbon wheels, made for better acceleration.

The Prime RP-38s are quite versatile wheels, the definition of an all-rounder.  You can take them into mountains, ride them on flat and hilly roads, rain or shine, no worries about cross winds and set them up tubeless to be comfortable if not particularly fast.  While quite a few alloy wheels at the same price point or less can give you a similar and perhaps faster experience, if you want carbon wheels on a budget, these are worth a look.  They’re available by clicking this link.


  • Hi,

    What a tremendous job you do.
    I don’t by any cycling gear until your site is referenced.

    Have you considered reviewing the Reynolds, direct to consumer, line of wheelsets?

    • Thanks Bud. You’re very kind. Regarding Reynolds, I’m not familiar with a direct to consumer line. Please tell me more. I have reviewed several of their wheelsets, any of which you can find by entering the name of the wheelset in the search box at the top of each page. Steve

  • Thanks. Any chance you’ll review one of the Specialized Roval options (e.g. CLX 40)?

    • Hi Jeff. I had a review of it up before (wasn’t a star – summary here) but took it down as Roval have replace the wheelset with the CLX32. Steve

  • Hi Steve, I wonder how they would perform on gravel or on a CX course where aero benefits are not as important as a deeper rim to clear mud and sand faster.

  • Christoph, I’ve no idea. I only took them on the road. Steve

  • I was wondering how do these wheels compare in quality to the old Reynolds Assault, dv46, or r6 in quality since these rims are at a similar price point to the Reynolds Rims. Also you mentioned that these rims are made in China are there any other Chinese wheelsets you recommend.

    • johny, As I hope you can see from the comparison chart, I didn’t rate them as well as the Reynolds Assaults on several performance characteristics. The fact that they are made in China doesn’t predict their performance as most wheelsets (and bikes and other components) are made in either Taiwan or mainland China these days. The ability to have them made to your specifications which emanate from your research, design and testing is more likely to produce the performance you want than when they are not. In this case, the RP38 are made from a design developed and owned by the rim maker that Prime sourced the wheelse from. These “open mould” rims, assembled with spokes and hubs sourced from other providers are more typical of many of the lower priced wheelsets sold directly from China these days. Steve

  • Hi, Steve, I’ve found these wheels interesting for me because I participate in different races/marathons on flat terrain on distance 70-100km, however one of the judges said he was disappointed that a 38mm deep wheelset performed more like 25mm alloys than 40mm carbon ones… I know you have big experience in comparing different wheelsets so maybe you could recommend some model for flat terrain races where mainainting high speed (35-40km/h) is priority? Is it possible that due to the aero wheels in my price range, my average speend would be higher on flat terrain. The price would be around 1000euro. I check prices on, the shipment would be to EU.

  • Thanks for the review. Anyway I would like to put the gp4000s clincher tyres on it. But which one do you think better fitting with the wheel, 23 or 25mm?

  • Fantastic wheels out of the box but be prepared to be replacing spokes every few hundred miles . I have owned a set for 12 months and only ridden them for 6 . Completely rebuilt by chain reaction they lasted nearly 800 miles , then due to “wear and tear “ popped again , put the extra and get a reliable set

  • Hi Steve, just wondering what price point these were reviewed at? i am looking at my first wheel upgrade and the RP 38 Discs have caught my eye due to reviews and price. i can currently purchase them for around £600.

    Would you recommend the RP38’s at good value at that price?


    • Chris, My review of their performance is independent of the price. If you good with the pros and cons of the performance as described, then the less you can get them at the better the value. Steve

  • Luigi Borromeo

    Hello Steve,

    Your articles are absolutely great. I keep on reading them. Really thanks a lot

    I am 64kg, and starting racing criteriums.

    I bought a pair of Prime RR-50 wheels, that are – like the Prime Rp38 – 16.5 internal width and 25mm external width. Paid 500£ on offer I still have time to return these wheels.

    Few questions:
    – if I keep the Prime RR-50 I’d use CONTI GP4000ii or Schalbe Pro One, 23mm in front to get the aero benefit, and 25mm back to improve comfort and cornering. Does it sound good ?
    – Would it worth it an upgrade to Easton EC 90 55 wheels for extra 600£?
    – For better cornering, it is more important the front or rear wheel ?
    – For criterium, when cornering and handling are very important, does it make a big difference shifting from 16.5 to 19 or wider rims?

    Thanks a lot,

    • Elvis, Grazie for the feedback and for supporting the site by purchasing your gear through the store links in the post. I’d use the same width tires front and back for crits. You’ll get more consistent handling and better rear aero performance, if only a little, than if your run 23C on the front and 25 on the back and you really should prioritize speed over comfort in a crit.

      Judging from comparing the Prime RP-38 and Easton EC90 SL, I’d think the Easton EC90 55 very likely a better wheelset than the Prime RR-50. You can read my review of the Easton EC90 55 in my post The Best Aero Bike Wheels. Wider rims will give you better handling but you’ll note from the review that you don’t necessarily want to go to wider tires on these wheels or any other wheels you plan to ride above 30 kph if max speed is your primary objective.

      It’s really up to you to determine whether the improved performance will be worth your money. That’s a question I have a hard time answering for myself most of the time, let alone trying to answer for a fellow roadie! Cheers, Steve

  • Hi Steve,
    Just wondering if we compare these wheels with Fulcrum Zero / Campag Shamal (aluminium version), which one would you recommend for climbing ? Thank you.

  • I bought a set of the disc versions of these wheels and have found them quite good, light enough considering they are disc wheels.

    The bearings though are atrocious and had to be replaced at approx. 1500kms, the originals were amigo brand bearings and the rear wheel is going in the same direction too

  • Hello Steve. Any review about FFWD F4R FCC 2019 with dt swiss 240 hub? Seems the completely redesign their wheels. Would be nice have your impression about this wheels.

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