Rolf Prima Ares TT Disc Brake Rear Wheel
The Rolf Prima Ares TT Disc rear wheel is a full disc rear for time trial and triathlon bikes with disc brakes. Rolf builds it in collaboration with HED Composites on its tubeless-ready Ares6 carbon profile, so you get a disc wheel with a 20mm inner width clincher bed rather than the narrow tubular or old-style clincher beds many disc wheels still use. It weighs 1195 grams and is built to order in Eugene, Oregon.
It is for the rider who races against the clock on a disc-brake TT or tri bike and wants the last aerodynamic step past a deep spoked wheel. A disc rear is the fastest rear wheel on a flat or rolling course, and the Ares TT Disc pairs that with Rolf's US-made hub internals and a modern tire bed.
There are no paired spokes on a disc, but Rolf's paired-spoke design still matters here because the Ares TT Disc is meant to be run with an Ares6 Disc front. That front carries 20 paired spokes on a 60mm rim, which is how Rolf keeps the front light and aero enough to match the disc behind it. Rolf sells the two together as a race kit, which we also list.
Design and construction
The Ares TT Disc rear wheel is a carbon disc built on the Ares6 clincher profile: 20mm inner width, tubeless compatible and taped from the factory. The disc structure comes from HED Composites, with the rim bed, hub and assembly by Rolf. Rim depth is not listed because the wheel is a full disc.
The hub is Rolf's XST 4.4, designed and manufactured in the USA and assembled in Eugene, running Enduro steel cartridge bearings. It uses the T2 high engagement drive, a 48-tooth drive ring with three independently sprung steel pawls that Rolf rates as twice as fast to engage as its earlier 24-tooth ring. The freehub body is CNC-machined 6Al-4V titanium and is offered in Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12 and Campagnolo N3W.
Brake interface is Center Lock disc. Rear axle is offered as 142mm thru axle or 135mm quick release. The Ares TT Disc is disc brake only; there is no rim brake version.
How it rides
A disc rear changes the character of a bike more than any other single wheel. The Ares TT Disc rear wheel holds speed remarkably on flat and rolling roads, and because Rolf builds it on a wide tubeless clincher bed it does not have the harsh, skittish feel of older narrow disc wheels. Rolf describes the ride as compliant compared with traditional TT discs, and with a 25mm or 28mm tubeless tire at sensible pressure that is what you get.
It suits triathletes from sprint to full distance, time trialists on disc-brake frames, and anyone chasing a personal best on a flat course. Side winds act on a disc rear as a push at the back of the bike, which most riders find easier to manage than a deep front; it is the front wheel that dictates whether a day is rideable, which is one reason Rolf pairs this disc with the 60mm Ares6 rather than something deeper.
Specifications
| Wheel type | Road |
|---|---|
| Rim | Carbon clincher |
| Rim depth | Full disc |
| Rim width | 29mm, 20mm internal |
| Brake | Disc Brake |
| Rear axle | 142mm, 135mm |
| Freehub | Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12, N3W |
| Tire size | Please refer to chart in product images |
| Weight | 1195g |
| Includes | Taped for |
What this page sells
About this Ares TT Disc Brake Rear Wheel listing. The choices on this page are rear axle: 142mm Thru Axle Rear, 135mm QR Rear; driver type: Shimano HG 10/11, SRAM XDR, Campagnolo, Campagnolo N3W. Price and availability follow Rolf Prima's own list, refreshed every night.
Fit and compatibility
The Ares TT Disc rear wheel fits disc-brake TT and triathlon frames with a 142mm thru axle or 135mm quick release rear, chosen at order time. Rotor mount is Center Lock, so 6-bolt rotors need an adapter. Freehub bodies are Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12 and Campagnolo N3W, all titanium. It does not fit rim brake frames.
Tires follow Rolf's 20C road rim guidance: 23mm to 32mm, with maximum pressures of 110 psi at 23 to 25mm, 100 psi at 28mm and 80 psi at 30 to 32mm. For a disc rear a 25mm or 28mm tire is the usual choice. Check your frame's clearance at the seat tube and chainstays, as some TT frames are tight around a full disc.
Rolf Prima's testing and certifications
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)
The figures, certificates and media above are Rolf Prima's own. ProWheelBuilder does not run these tests; we sell the wheel and stand behind the order.
A note on Rolf Prima
Rolf Prima builds by hand in Eugene, Oregon. Hand-built at the factory means what it means here, that each wheel is tensioned and trued by a person rather than released by a machine, which is why we are comfortable selling them beside the wheels we build ourselves.
Ordering it from ProWheelBuilder
Rolf Prima builds every Ares TT Disc rear wheel to order in Eugene, Oregon, with the disc structure from HED Composites. ProWheelBuilder in Georgia sells it, confirms your rear axle and freehub against your bike, and sends the order to Rolf. We ask what frame you are fitting it to, because disc rears and TT frames have more clearance surprises than any other combination we deal with, and it is easier to catch that before Rolf builds the wheel.
If you want a spoked rear instead, the Ares6 Disc is the matching wheel. If you want a custom deep-section rear on a hub of your choice, we build on Astral rims, Rolf's own rim brand.
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.
Ares TT Disc Brake Rear questions
Is ProWheelBuilder the manufacturer of the Ares TT Disc?
No. Rolf Prima builds the Ares TT Disc rear wheel in Eugene, Oregon in collaboration with HED Composites. ProWheelBuilder is a reseller in Georgia that sells it, checks your order and advises on fit.
Is the Ares TT Disc a front wheel or a rear wheel?
Rear only. Rolf recommends pairing it with an Ares6 Disc front, and sells the two together as a race kit.
Is it tubeless?
Yes. It is built on the tubeless-ready Ares6 clincher profile with a 20mm inner width and ships taped.
What axle and freehub options are there?
142mm thru axle or 135mm QR rear; titanium freehub in Shimano HG 10/11, SRAM XDR 11/12, Campagnolo 11/12 or N3W. Rotor mount is Center Lock.
Can I use it on a rim brake TT bike?
No. The Ares TT Disc is disc brake only.
How much does it weigh?
Rolf lists 1195g for the rear wheel.
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.
