Rolf Prima Ares4 ES Disc Wheelset
The Rolf Prima Ares4 ES Disc takes the 42mm carbon Delta rim from the Ares4 Disc and pairs it with Rolf's XR 3.1 hubset to bring the price down without changing the rim or the builder. It weighs 1665 grams (750g front, 915g rear), is tubeless ready, uses 24 paired spokes per wheel, and is laced by hand in Eugene, Oregon like every other Rolf wheel.
This is the Ares4 for a rider who wants an aero carbon road wheel with real US hand-building behind it, but who would rather spend the difference on tires and race entries than on titanium freehubs and US-machined hub shells. It is also the Ares4 that supports Shimano Micro Spline, which matters if your road or all-road bike runs a GRX 12-speed drivetrain.
Paired-spoke construction is the same on the ES as on the top-tier Ares4 Disc. Spokes come to the rim in pairs so their sideways pull cancels at each pair, and the 42mm carbon rim is not bent between single spokes. That is what lets Rolf build a light rim into a durable wheel with fewer spokes than a conventional design, and on the Ares4 ES Disc it does so with 24 per wheel for a bit of extra margin.
Design and construction
The Ares4 ES Disc rim is a carbon clincher, 42mm deep, 20mm inner width, in Rolf's Delta profile. It is tubeless ready and arrives taped. It is the same rim as the standard Ares4 Disc, so the aero behavior and crosswind stability are identical.
Hubs are Rolf's XR 3.1, designed in the USA, with sealed steel cartridge bearings and a forged aluminum freehub body. Rotor mount is Center Lock. The front axle is 12mm thru and the rear is 142mm thru axle. Freehub bodies offered are Shimano HG 11, SRAM XDR 11/12 and Shimano Micro Spline 12. The XR 3.1 does not have the T2 high engagement ring or the titanium freehub found on the XST 4.4.
Spokes are Sapim CX Speed bladed, 24 front and 24 rear, paired. Rolf notes that the Ares4 ES Disc ships within about a week of an order being processed, since it is built to order rather than stocked.
How it rides
On the road the Ares4 ES Disc gives you almost all of the standard Ares4 Disc experience: the same rim shape carrying speed on the flat and behaving itself in side winds, the same quick response from a stiff, high-tension paired-spoke wheel. The differences are a slightly slower hub pickup, because the XR 3.1 lacks the 48-tooth T2 ring, and around 145 grams of extra weight concentrated in the hubs and the four extra spokes per wheel, which is felt less than rim weight would be.
The Ares4 ES Disc suits riders upgrading from stock alloy wheels on a disc road bike, riders who race occasionally and train a lot, and anyone who wants an aero carbon wheel with a proper warranty at a sensible price. The extra spokes make it a slightly better choice than the 20-spoke Ares4 Disc for heavier riders.
Specifications
| Wheel type | Road |
|---|---|
| Rim | Carbon clincher |
| Rim depth | 42mm |
| Rim width | 28.5mm, 20mm internal |
| Brake | Disc Brake |
| Spoke count (F/R) | 24/24 |
| Spokes | Sapim CX Speed, bladed |
| Hubset | XR 3.1 Steel cartridge bearings |
| Front axle | 12mm |
| Rear axle | 142mm |
| Freehub | Shimano HG11, SRAM XDR 11/12, MS12 |
| Tire size | Please refer to chart in product images |
| Weight | 1665g [750g/915g] |
| Includes | Taped for |
This version
This page is the Ares4 ES Disc Wheelset itself, not a custom build. The choices on this page are driver type: Shimano HG 10/11, SRAM XDR, Shimano Micro Spline. This listing is the complete wheelset - front and rear together, not a single wheel.
Fit and compatibility
The Ares4 ES Disc is disc brake only with Center Lock rotors. Front axle is 12mm thru and rear is 142mm thru; there is no 135mm QR rear option on the ES hubs, and Rolf does not list a front conversion kit on this model, so confirm your bike is 12x100 front and 12x142 rear before ordering. Freehub options are Shimano HG 11, SRAM XDR 11/12 or Shimano Micro Spline; Campagnolo bodies are not offered.
Rolf's tire chart rates its 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. Use the lower of Rolf's number and the tire maker's.
What Rolf Prima says about testing
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)
Rolf Prima publishes those results; ProWheelBuilder sells the finished wheel and does not test it in a lab.
A note on Rolf Prima
The Vigor is Rolf's longest-running profile and their best seller, and the ES version has been a staple of triathlon wheel choices for fifteen years. A rim shape that survives that long in a market this faddish is usually telling you something.
Ordering it from ProWheelBuilder
Rolf Prima builds each Ares4 ES Disc to order in Eugene, Oregon. ProWheelBuilder in Georgia sells it, checks your freehub choice against your cassette, confirms your frame is 142x12 and your fork 100x12, and hands the order to Rolf for building and shipping. If you are not sure which of those your bike is, send us the model and year and we will look it up.
If you want the T2 drive, titanium freehub and extra axle options, the standard Ares4 Disc is the step up. If you want a different hub altogether or a custom spoke count, we build wheels on Astral rims, Rolf's own rim brand, right here.
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. Because this wheelset comes assembled from its maker, the warranty that applies is theirs, set out above; ProWheelBuilder's one-year wheel warranty is for wheels we build here. Either way, a claim goes through us and we will manage it.
Full terms are on our Policies & Warranty page.
Ares4 ES Disc questions
Is ProWheelBuilder the manufacturer of the Ares4 ES Disc?
No. Rolf Prima hand-builds the Ares4 ES Disc in Eugene, Oregon. ProWheelBuilder is a reseller in Georgia that sells it, checks your order and advises on compatibility.
What is the difference between the Ares4 ES Disc and the Ares4 Disc?
The rim is the same 42mm carbon Delta profile. The ES uses XR 3.1 hubs with steel cartridge bearings and an aluminum freehub, 24 spokes per wheel, at 1665g. The Ares4 Disc uses US-made XST 4.4 hubs with T2 drive and a titanium freehub, 20 spokes per wheel, at 1520g.
Which freehub bodies are available?
Shimano HG 11, SRAM XDR 11/12 and Shimano Micro Spline 12.
What axle standards does it use?
12mm thru axle front and 142mm thru axle rear, Center Lock rotor mount.
What tire sizes does Rolf recommend?
23mm to 32mm on the 20mm inner width rim, per Rolf's tire chart. A 28mm tubeless tire is a good all-round choice.
Is the Ares4 ES Disc tubeless?
Yes. The rim is tubeless ready and ships taped; add valves and sealant.
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.
