Rolf Prima EOS4 Front Disc & EOS6 Rear Disc Carbon Wheelset
The Rolf Prima Eos4 front and Eos6 rear wheelset is Rolf's mixed-depth race set: a 42mm Eos4 front wheel for handling and a 60mm Eos6 rear for speed, both on Rolf's flagship 7.0-level hubs with Enduro XD-15 ceramic bearings. It is sold as one product with a brake type choice, so you order it as a disc set on XST 7.0 hubs or as a rim brake set on TdF 7.0 hubs. Either way it is built to order in Eugene, Oregon.
The logic is simple. A deep front wheel is what gets pushed around in crosswinds; a deep rear wheel mostly just goes faster. By putting the Eos4 up front and the Eos6 behind, Rolf gives you most of the aero benefit of a 60mm pair with the composure of a 42mm front. It suits racers, triathletes and fast riders who train on exposed roads and do not want to swap wheels for windy days.
Paired spokes are how both wheels stay light. Each pair of spokes meets the rim together so their sideways pull cancels at the pair, letting Rolf carry higher tension on fewer spokes; the disc Eos4 front uses 20 and the rim brake front just 14. On the Eos4 front and Eos6 rear wheelset that adds up to a 695-gram front and an 890-gram rear in disc form.
Design and construction
The front is an Eos4 rim: carbon clincher, 42mm deep, 20mm inner width, Delta profile. The rear is an Eos6 rim: 60mm deep, 19.5mm inner width. Both are tubeless compatible and ship taped. Rolf lists the disc front at 695 grams and the disc rear at 890 grams.
Hubs depend on the brake type you choose. The disc set uses XST 7.0 hubs with Center Lock rotor mounts; the rim brake set uses TdF 7.0 hubs with quick release axles. Both are designed and manufactured in the USA, assembled in Eugene, coated in Rolf's ballistic armor Cerakote finish and fitted with Enduro XD-15 ceramic bearings. The rear hub in either case uses the T2 high engagement drive, a 48-tooth ring with three sprung steel pawls, and a CNC-machined 6Al-4V titanium freehub in Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12 or Campagnolo N3W.
Spokes are Sapim CX-Ray bladed, paired. Rolf lists the disc front at 20 spokes and the rim brake front at 14, with the rim brake rear at 16; the disc rear follows the 20-spoke Eos6 Disc. Disc axle options are 15mm, 12mm or 9mm QR front and 142mm thru or 135mm QR rear.
How it rides
The Eos4 front and Eos6 rear wheelset feels like a race wheelset that you can ride every day. The front tracks calmly in gusts and steers precisely, while the 60mm rear keeps the bike rolling on the flat and on long false flats. The XD-15 bearings and 48-tooth T2 drive give it the free-coasting, instant-pickup character shared by all Eos wheels, and the paired-spoke build keeps both wheels stiff under hard efforts.
The Eos4 front and Eos6 rear wheelset suits road racers who want one set for crits, road races and windy training loops, triathletes who are nervous about a deep front, and strong riders on rolling terrain. It is not the choice for mountainous riding, where the shallower Eos3 or Eos4 pair is lighter, nor the fastest possible setup for a flat time trial, where a full Eos6 pair or an Ares TT Disc rear wins.
Specifications
| Wheel type | Road |
|---|---|
| Rim | Carbon clincher |
| Rim depth | 42mm front / 60mm rear |
| Rim width | 19.5mm inner |
| Brake | Disc Brake |
| Spoke count (F/R) | 20/20 |
| Spokes | Sapim CX Ray, bladed |
| Hubset | XST 7.0 [Disc]/ TdF7.0 [Rim |
| Front axle | [Disc]: 15mm, 12mm, 9mm |
| Tire size | Please refer to chart in product images |
| Weight | 695g |
| Includes | Taped for |
| Second build weight | 890g |
| Second build brake | Rim or Disc |
About this listing
What you are buying here is the EOS4 Front Disc & EOS6 Rear Disc Carbon Wheelset. The choices on this page are front axle: 15mm Thru Axle Front, 12mm Thru Axle Front, 9mm QR Front. This listing is the complete wheelset - front and rear together, not a single wheel.
Fit and compatibility
Choose Disc Brake or Rim Brake when ordering the Eos4 front and Eos6 rear wheelset; they are different hubs and the wheels are not convertible afterward. Disc: Center Lock rotors, 15mm, 12mm or 9mm QR front, 142mm thru or 135mm QR rear. Rim brake: quick release front and rear for 100mm and 130mm spacing, with a carbon brake track. Freehub bodies in either version are Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12 and Campagnolo N3W in titanium. Rolf includes a valve extender and, on the rim brake set, quick release skewers.
Rolf's tire chart rates its 19C and 20C road rims for 23mm to 32mm tires, with maximum pressures of 110 psi at 23 to 25mm, 100 psi at 28mm and 80 psi at 30 to 32mm. A 25mm front and 28mm rear, or 28mm on both, works well with these rim widths.
Testing, standards and warranty at Rolf Prima
Rolf Prima builds every complete wheelset by hand at its facility in Eugene, Oregon. The company states that all orders are built by hand there by its own builders, and describes its process as building each wheel three times with two stress cycles in the build to seat and stretch all components. Rolf Prima says hand building lets it hit uniform spoke tensions that machine building cannot match, and that its design allows higher and more targeted spoke tension than a traditionally laced wheel, which it credits with increasing stiffness and improving spoke durability by decreasing the load cycle on each spoke.
The defining feature of a Rolf Prima wheel is Paired Spoke Technology, introduced in 1997. Bringing the spokes to the rim in pairs neutralizes the left and right outward pulling forces, which Rolf Prima says allows it to build true wheels on lighter rims with fewer spokes. Fewer spokes and lighter rims are the basis of the brand's aerodynamic and weight claims. The wheel systems combine paired spokes with the Delta rim profile, internal nipples, and patented details including the Jacketed Nipple, Self-Aligning Nipple, Differential Flange Diameter and Dish Reducing Design. Rolf Prima cites eleven patents behind its technology.
Rolf Prima runs an in-house engineering and testing lab and states it uses the ISO 4210 standard as a base starting point but considers it not tough enough, so it applies its own in-house standards. Published test capabilities include an in-house drum fatigue tester it calls the Thrasher, which compresses years of riding into days; an impact test using a weight calibrated steel anvil that exceeds the UCI 40 joule requirement, striking at spokes, between spokes and at the valve hole; lateral and radial stiffness measurement of rims alone and complete wheels; brake energy, distance and temperature testing developed for carbon clinchers; wind tunnel evaluation; and field testing by sponsored athletes. The Certainty page cites over 10,000 hours of lab testing to above industry standards.
On racing eligibility, Rolf Prima explains that UCI approval only matters for mass start UCI road races, UCI cyclocross and draft legal ITU triathlon. Its standard wheels (Aspin and the Elan family) do not require approval, while most of its deeper or lower spoke count models are non standard and are listed on the UCI approval registry. Rolf Prima does not publish a fixed rider weight limit; it says every wheel has limits that involve riding style and road conditions as well as weight, and directs heavier or more aggressive riders toward stiffer models such as Vigor, Echelon or Ares6. All road wheels can be set up tubeless with the brand's tubeless kit, and adventure, cyclocross and mountain models ship tubeless ready with tape and valves installed.
Rolf Prima backs its wheels with the Certainty program: a five year warranty against defects in materials and workmanship for the original owner, lifetime crash replacement at a discount for registered wheels, a 30 day trade out or return window in the USA, replacement parts availability for any Rolf Prima wheel regardless of age, and stated service response times of same day to 24 hours on calls and email with service work resolved within three days of receipt.
Rolf Prima's videos
From Rolf Prima
Warranty and certifications
- Limited warranty — Five years from original retail purchase against defects in materials and workmanship (2016 and newer wheels), original owner, non transferable; decals and bearings two years (source)
- Certainty program — Five year warranty, lifetime crash replacement, 30 day trade out or return in the USA, replacement parts for any Rolf Prima wheel regardless of age, same day to 24 hour service replies, service work resolved within three days of receipt (source)
- Crash replacement — Lifetime crash repair or replacement discount for the original owner; wheels must be registered within 30 days of purchase; proof of purchase and serial numbers required; freight not covered (source)
- UCI approval — Non standard models (rims taller than 25 mm, fewer than 16 spokes) are listed on the UCI approval registry; Aspin and Elan are standard wheels that need no approval (source)
- Test standards — ISO 4210 used as the base with tougher in-house standards; impact test exceeds the UCI 40 J requirement; in-house drum fatigue, stiffness, brake and wind tunnel testing (source)
- Hand built in USA — All wheels hand built in Eugene, Oregon; each wheel built three times with two stress cycles; eleven patents (source)
Sources on Rolf Prima's site:
- Rolf Prima: Testing
- Rolf Prima: Paired Spoke Technology
- Rolf Prima: Our Technology
- Rolf Prima: Certainty Program
- Rolf Prima: Warranty
- Rolf Prima: FAQ (UCI, rider weight, build process)
Everything in this section is published by Rolf Prima. ProWheelBuilder is the seller, not the tester, and the wheel reaches you as the maker builds it.
A note on Rolf Prima
Rolf still fields service questions on Vector wheelsets with thirty years and more of riding on them. That is the practical case for a company that stayed in one place doing one thing: the wheel is older than a lot of bike shops and can still be sorted out.
Ordering it from ProWheelBuilder
Rolf Prima builds every Eos4 front and Eos6 rear wheelset to order in Eugene, Oregon in whichever brake configuration you choose. ProWheelBuilder in Georgia sells it, takes your brake type, axle and freehub selections, checks them against your bike, and passes the order to Rolf. If you are unsure whether you want the mixed-depth set or an Eos6 Disc pair, tell us your weight and the roads you ride and we will give you a direct answer.
If you want a mixed-depth carbon set on a different hub, we build custom wheels on Astral rims, Rolf's own rim brand, and can mix depths front and rear.
Warranty
Manufacturer's warranty. Rolf Prima gives a one-year limited warranty on its wheels under normal use. Astral is Rolf Prima's rim brand; ask us and we will confirm the current terms for the exact rim before you buy.
ProWheelBuilder. These wheels were built at the factory, not on our bench, so it is the maker's warranty above that stands behind them - our own one-year wheel warranty covers wheels we lace ourselves. If you do need to claim, we will deal with the manufacturer for you.
Full terms are on our Policies & Warranty page.
EOS4 Front Disc & EOS6 Rear Disc Carbon questions
Is ProWheelBuilder the manufacturer of this wheelset?
No. Rolf Prima hand-builds the Eos4 front and Eos6 rear wheelset in Eugene, Oregon. ProWheelBuilder resells it from Georgia, verifies your order and advises on brake type, axle and freehub choices.
Is this one product or two?
One product. Rolf sells the Eos4 front and Eos6 rear as a set with a Brake Type choice: disc on XST 7.0 hubs or rim brake on TdF 7.0 hubs.
Why mix a 42mm front with a 60mm rear?
The front wheel is the one that gets moved by crosswinds. A 42mm front keeps handling calm while the 60mm rear provides most of the aero gain of a deep pair.
What are the rim widths?
Eos4 front: 20mm inner. Eos6 rear: 19.5mm inner. Both are tubeless compatible carbon clinchers.
Which freehub bodies are available?
Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12 and Campagnolo N3W, all titanium, on both disc and rim brake versions.
What bearings are fitted?
Enduro XD-15 ceramic bearings in both the XST 7.0 and TdF 7.0 hubs.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build wheels for a living.
