Prime is a UK-based brand which produces a range of components, ranging from wheels to handlebars, in alloy and carbon, across road, time trial, gravel and MTB disciplines.
Much of the brand’s R&D is conducted at the Silverstone Sports Engineering Hub, where their products are tested for both aerodynamics and rolling resistance – as are many of the best road wheels. This is in addition to heavy use of Computer Fluid Dynamics (CFD) in Prime’s development cycle.
Prime Primavera 44 road wheels: The construction
The Prime Primavera 44 road wheels are a ground up redesign of the previous Prime Black Inc wheels, which represented the top flite of Prime’s wheel range line-up.
The new rim profile employed many hours of CFD modelling in its design phase, with a particular focus on the effect the spokes have on the air flow. Interestingly, there are brands which chose to ignore the effect of the spokes in their computer modelling – but Prime has sweated the details on these.
The rims themselves are tubeless-ready and have a hooked profile for greater compatibility with various tyres. Rim width is 23mm internal and 30mm external, which is wide, but not boundary pushing, and has been chosen for the balance between aerodynamics, rolling resistance and tyre compatibility.
Claimed weight is 1,378g but they came up as 1,571g total on my scales – that was with rim tape fitted and tubeless valves, but even so, it doesn’t fully explain all of the extra 150g.
24 straight-pull spokes are used front and rear, and are a mixture of DT Swiss Aerolite (drive side) and Aerocomp (disc side), to better optimise stiffness and replaceability. A large part of Prime’s vision for these wheels was not solei the performance aspects, but also their serviceability and service life. DT Swiss Pro Lock Squorx nipples are used as they are supposedly easier to get the ideal tension balance across the rim.
The hubs are one of the largest areas of development for the wheels, with the rim being designed around them – hence why Prime will be offering the hubs separately for custom builds. They go by the name SR1D and are made of CNC machined 7075 aluminium. The bearings are fairly standard – again to make the wheels more easily serviceable and easier to live with
The front hub uses two 6803 bearings whilst the rear uses one 6902, one 17287 and the freehub using two 6802 bearings. In the standard setup, the system uses a 36T dual-sprung star ratchet, which means engagement occurs at around 10˚ rotation (depending on crank length) compared to generally around >12˚ for many wheels.
For those who want even faster engagement, there is a 52T upgrade available which promises to be easily switchable and reduce that engagement angle down to just 6˚. Prime does state that the 52T is not as durable as the 36, and so recommend switching between them depending on what point of the season you’re in. Faster engagement in the summer racing season, slow engagement for winter training.
Along with the wheels, in the box you get four spare spokes and nipples, tubeless valves, QR skewers, a 10 speed spacer, 15mm Thru axle end caps, and QR end caps. Prime also offers a crash replacement policy where if damaged beyond repair in a crash or accident, you can get a new set of wheels at 40% off if it occurs within 2 years of original purchase.
I set the wheels up with some Continental GP5000 TL 25mm tyres, with one being very easy to slip on and the other presenting something of a wrestling match – as to which was to blame, I think it’s more likely the fault lies with the second tire rather than the other wheel.
Once on, neither tire needed sealant to get inflated nor to maintain pressure, which was very impressive. Being 25mm tires on 23mm rims, they did come up quite plump, measuring 27mm across at the widest point – 28mm would have been a better match.
Going from box section aluminium rims straight to 44mm carbon deep sections it was noticeable that the wind does catch the wheels, especially on a blustery days. But although you can feel the force pressing against the rim, there was no buffeting and it didn’t feel like my wheels were being caught and grabbed by the wind at all.
Put it this way, I could happily ride no handed to put a jacket on down a line of interrupted hedgerows where clearings led to gusts of wind moving the wheels but in a controlled manner. In this respect they perform better than other deep section rims I’ve used in the wind.
I chose a particularly lumpy test route which mixed some steep climbs with technical descents and a flat finish. On the inclines, going out of the saddle and attacking the climbs, the wheels showed no signs of flex and responded very well. I find with my training wheels that out of the saddle there is lateral movement in the hub that causes the rotors rub – no such issue with the Primes.
I wouldn’t call them snappy, but they do feel light and stiff for climbing and getting up to speed as well, which is nice given they are a decent depth of rim. Descending they felt planted and on a twisty downhill where I was happily able to gap the cars behind me even with the wind blowing hard.
Once onto the flats, the wheels roll tremendously well, keeping their speed with relative easy. Opening up for a sprint, they feel very well connected to the bike and you don’t feel like any power is wasted. I was comfortably able to hit a higher speed than usual for similar power on my regular sprint section of the test loop.
Part of this will be the 36t star ratchet which engages very quickly for sharp accelerations. Essentially, the wheel engages after 10 degrees of rotation. For those racing crits and wanting even more punch, there is a 52t add on that you can purchase for even faster engagement as only ~6-7 degrees of rotation is required before it picks up.
The matt black carbon finish does lend itself to getting very filthy when there is a muddy puddle or two on the loop, but this is easy to clean off.
At $959.99 / £899.99, these wheels feel significantly better than several $2,000 / £1,500+ sets of wheels that I’ve used recently. They are easily as stiff, and if anything roll better on the flat roads.
Compared to other wheels available on the market, the most direct competitors are likely to be the Hunt Aerodynamicist 44 (£879.99 / $919), Scribe Inception Aero Wide+ 42-D (£720 / $1,000), Zipp 303S (£1,090/ $1,346.0) and the Vel 50 RL (£749).
The Primes are competitively weighted compared to all of these wheels. The Hunt wheels come in slightly lighter – but every other wheelset listed here is heavier. All of these wheels feature a similar rim depth and construction too (the Zipps are hookless rims).
A big plus point for the Prime wheels is their construction, use of regular sized bearings, steel components and standard spokes. This means that maintenance, replacement components, and longevity of components should be longer lasting and cheaper to replace. In the long run, that could make these cheaper wheels to maintain and less likely to have issues that require expenditure of money. That was Primes goal with these wheels.
These wheels do everything right. Tubeless installation is easy, hub engagement is super-fast, they are stable in cross winds and roll very well on the flats. The only area where they aren’t perfect is on steep climbs (+12%) but everywhere else they perform exceptionally.
Price-wise they are very competitive, and in many areas outperform similarly priced rivals. The use of standard bearing, spokes, and long lasting materials is a big bonus to ensure that the wheels are cheaper to maintain and should last a long time, potentially making the long term cost of these significantly better than the competition.
The option for hub upgrades and ease of getting aftermarket ceramic bearing options is also a very nice addition so these wheels can easily be switched between training wheels, and even faster race spec easily.