Light rims are responsible for extremely low acceleration values so that not even the tiniest bit of energy is wasted on uphill climbs; these stable rims with a high spoke tension of 140 kgf also ensure maximum stiffness. Thanks to the stress-optimized reinforced spoke holes laminated and reinforced during production no additional drilling is necessary, making weaknesses in structure a thing of the past. This guarantees safe and accurate downhill handling and makes these wheelsets the real kings of the hill, while their profile lets them strut their stuff even on flat surfaces.
By using materials from Formula 1 not freely available on the market and exceptional manufacturing processes, ax.specialists have succeeded in developing the Ultra 27.5C wheelset with the sensationally low weight of only 1215 grams per set with Extralite hubs. Thanks to special lamination techniques the robustness allows for a rider weight of up to an impressive 100 kilograms.
"Form follows function" becomes "form follows flow" with the Ultra MTB wheelsets. Through its extraordinary rim shape, which almost looks like a heart in its cross-section, the ax-lightness wheelsets can overcome practically any obstacle. Even when riding through deep sand, ruts or mud, the tires practically dig themselves out thanks to the Easy Release Technology so the rider quickly regains a secure grip under the wheels. From an optical perspective the Ultra MTB wheelsets are enticing with their modern and unique design.
Specifications - Ultra 27.5C
Laminated spoke holes
|Weight (+/- 5 %)||1215 g/set|
|Rims||ax XC 27.5C|
|Rim material||Full Carbon|
|Tire type||Clincher, Tubeless|
|Brake type||Disc brake - 6-Bolt|
|Rim depth||30 mm|
|Rim width||33.5 mm|
|Inner width||25 mm|
|Hubs||Extralite HyperFront / HyperRear 2 (Boost: HyperBoost-F / HyperBoost-R)|
|Freehub||Shimano, Sram XD|
|Axle standards front||QR, 15mm thru-axle, Lefty, Lefty 2, Predictive Steering, Boost|
|Axle standards rear||QR, 142x12 thru-axle, Boost|
|Spokes||DT Swiss Aerolite, black|
|Nipples||DT Swiss Pro Lock Squorx Pro Head, external|
|Spoke tension||front: 100 kgf, rear driveside: 140 kgf|
|Spoke Count (f/r)||28 / 28|
|Intended use||MTB Cross-Country|
|Rider weight limit||100 kg|
|Tire pressure limit||1.7 - 2.0": 25 - 35 PSI, 2.1 - 2.5": 20 - 30 PSI|
Instead of simply drilling the spoke holes of our rims, we take a different approach with our rims: Every single spoke hole is crafted by hand and reinforced with strategically placed reinforcement patches.
The advantage is obvious: Where carbon is being drilled, one inevitably also cuts through fibres. A continuous fibre flow however is essential for the material to play its advantages such as the high tensile strength, even more indispensable for nipple holes that are exposed to high spoke tensions. Specifically crafted nipple seats allow an optimal orientation of the nipples and at the same time distribute the occurring forces evenly into the rim bed.
Independent testing at an university lab has confirmed the performance of this time and labour intensive approach: The rim is capable of withstanding nipple pulling forces of over 5000 N - circa twice as much as the best competitor and more than every hub flange or spoke would be able to endure. As a result our rims do not carry any spoke tension limit!
Us ourselves we are building our wheels with up to 140 kg of a spoke tension: A guarantor for you to have long-lasting joy with your wheels. The higher the spoke tension, the lesser the opportunity for a spoke to be unloaded upon an overload of the wheels (e.g. from a compression such as an obstacle, pothole or anything alike) and the wheels to therewith come out of true. That way you are longer able to ride with your perfectly trued wheels. As an additional advantage there also is minor increase in stiffness to be recorded.
An effort that pays off!
Extralite HyperHubs / CeramicSpeed Ceramic option
Our Ultra wheelset invariably rely on high performance hubs from Extralite. The Italian lightweights are some of the lightest hubs on the market. An intelligent, elaborate construction by means of FEM-analyses are a guarantor for a high durability, reasonable features such as an adjustable bearing play a high suitability for daily use.
New for 2017 we optionally offer our Ultra wheels with Ceramic hybrid bearings. As we do not settle with the second best, we only offer the highest quality of bearings from CeramicSpeed. The Danish specialists are renowned as the nonplusultra for years and have wins in about every single race globally available in their palmares.
All of our wheelsets are individually built by hand in our manufacture in Creußen, Bayern, to the tightest tolerances and with extremely high spoke tension. We refrain from the use of wheel building machines and invariably trust on the craftsmanship of specially qualified mechanics. The high experience with high-end-material allows a consistently high quality, the tight tolerance in lateral runout and radial runout a perfect runout and therewith a lot of joy with the wheels.