PRIME RP-38 – CAPABLE CARBON ALL-AROUNDERS FOR THE BUDGET MINDED
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.
Overall, 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 ITK10) 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 handle 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 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.