The wheel project was a natural progression of ultralight construction. In the beginning we used the mag wheels readily available and sold by various manufacturers. They were heavy and the axle width and design was not very friendly for adaptation to ultralight use. Ultralight wheels not only have to stand tremendous impact but also side loading like no narrow hub wheel will withstand.
In 2014 during the 23 bis. design it became obvious that a new spoked wheel was required. Afterall, a 1910 look-alike Demoiselle just wouldn’t look right with Skyway mags.
After searching the market in vain, we finally bowed to common sense and an all-new wheel design was eventually finalized. After prototype I, II & III construction and assembly, the resultant testing showed a fantastically strong and lightweight wheel.
The aluminum hubs are turned from 6061 T6 aluminum and the stainless steel spoke ring is pressed on to a shoulder. The titanium spokes are laced to a lightweight ‘Fat Bike’ bicycle rim. Rim selection is important, it must be able to accommodate the increased spoke to hub angle and it is advisable to utilize nipple washers. The assembly can then be fitted with the lightest tire and tube available.
In the early days we used anything and everything we could get our hands on. We broke so many wheels one summer, Skyway called and asked if we wanted to be a distributer. Most commercially available mag wheels simply don’t take much side loading. Spoked wheels are better but we ripped our fair share of them apart too.
Living in the ultralight world of give and take, high strength generally means more weight. Walking the fine line, but leaning to the side of “just strong enough” is the the solution we choose.
The hubs are machined from 6061 T6 solid bar. The short ones were made specifically for 20″ wheels while the longer ones are for 24″, 26″, 27.5″ or 29″. In the near future we will draw up a print with dimensions and all necessary info should anyone want to machine their own.
Spokes are arranged in all sorts of ways with the most common being a three-cross pattern. But why are the spokes laced this way and why are they sometimes set up differently? Most ultralight wheels are not required to handle hub torsion, i.e. Driving or braking. Unless you are ‘rim’ or ‘caliper’ braking, for ultralight use, a wide hub and straight or radial lacing provides the strongest wheel, both radial and sideways loading. If you need to brake off the hub, here are some spoking options.
The most common way for a wheel to be laced is with 32 or 36 J-bend spokes, arranged in a three-cross pattern. This means that every spoke intersects three others between the hub and the rim. Crossing the spokes over helps them handle the pedaling and braking torque being transmitted from the hub to the rim.
Two-cross spoke patterns are often found on high-end wheels. High-end wheels with straight-pull spokes often use just 28 or 24 spokes to save weight. This is possible because straight-pull spokes can be tightened to higher tensions than J-bend spokes. They’re often laced two-cross, because the lower spoke count means there are fewer spokes to cross over.
On the front hub, the non-drive side flange (the one next to the brake rotor) is closer to the center of the hub than the drive side flange is. The non-drive side spokes therefore require a higher tension to keep the wheel straight. To compensate for this, some front wheels have twice as many spokes on the non-drive side as the drive side.
4. Mavic Isopulse
Mavic’s Isopulse pattern improves the spoke angle to ease the load on the drive side spokes. On the rear wheel, it’s the drive side flange that’s closest to the center, so its spokes are under greater tension. Mavic’s Crossmax wheels use a radial (non-crossed) spoke pattern on the drive side. This improves the spoke angle to ease the load on the drive side spokes, while the non-drive side is laced two-cross to deal with braking and pedaling torque. Once upon a time i thought this concept was very state of art…
…then I saw a wheel from a 1928 Ford Model T.
Common types of spoke
• Straight-gauge spokes: These are the same width for their entire length (typically 2mm or 14-gauge). Simple and inexpensive, plain-gauge spokes are often used to build wheels where weight-saving is not an issue, such as heavy-duty BMX, MTB or touring bike hoops. They offer a slightly stiffer ride because of their thicker cross—section.
• Single-butted spokes: These spokes are slightly thicker in the neck of the spoke (the part closest to the hub) for extra strength and stiffness when building disc-brake wheels, and for heavier applications. They are slightly heavier than double-butted or plain-gauge spokes.
• Double-butted spokes: These are lightweight spokes that are thinner in the middle (e.g going from 2mm to 1.8mm and back to 2mm again) to save weight and reduce ride stiffness, without compromising on wheel strength. Double-butted spokes are lighter and more expensive than plain-gauge or single-butted spokes, and in their thinnest guises (e.g down to 1.5mm) may not be suitable for MTB riding.
• Aero bladed spokes: These have a flattened cross-section to reduce wind resistance. For time-trial bikes and race-oriented road bikes.
• Straight-pull spokes: These have no ‘j-bend’ at the flared (hub) end, the idea being that eliminated the bend cuts out a potential weak point in the wheel build, and also saves weight through the spoke being fractionally shorter (which adds up in a wheel with 20 or so spokes). They require a dedicated hub.