Few mechanisms are built at the edge of feasibility. It’s expensive to make stuff and we require some measure of reliability. Hence, over-design. However, cycling and aviation seem to push those limits like no one else. For very different reasons, each fights an uphill battle to succeed. Human safety is a big consideration for both. For more on the cycling-aviation relationship, check here.
A flying sensation is common to both.
We’re proud to announce the Wheel Fanatyk Tensiometer. Based on an ingenious Jobst Brandt (author of The Bicycle Wheel) design, this tool is the non plus ultra of tension gauges.
Inlaid, stainless, laser-etched nameplate.
FSA briefly made a version and it acquired an eclectic, worldwide following. It was discontinued several years ago and can no longer be found for sale. The Wheel Fanatyk tool upgrades the design in several crucial ways. To hear about the tool basics, in its FSA incarnation, check here. Read more →
[Note: this is #12 of a series of 20]
Designing wheels seems deceptively simple. Pick parts that fit the bike, ride, and budget. Make sure hub and rim drilling match and spoke length is correct. All too often, the design process is kept this simple and amazing opportunities are missed.
An exception is the fixie world, where a wheel’s cosmetic appearance gets special attention. Sure, beauty is only skin deep, but bravo to those designers who take the time to at least be fashionable. Got to love bikes where wheels make a visual statement.
www.statebicycle.com
[Note: this is #11 of a series of 20]
Don’t let stuck cogs interfere with wheel rebuilds.
When rear wheels need new rims and/or spokes, stuck cogs (or freewheels or cassettes) can prevent introducing new spokes. Gears sit near the drive side hub flange and you can’t get spokes in or out when they’re in place.
With multi-speed hubs and coaster brakes, the solution is to disassemble the hub. Remove the axle and all guts. Out comes the driver with the cog. The empty hub shell can easily be laced with a new rim. Now, reassemble the hub and finish the build. Reassembled, the hub will rotate accurately and you can true your wheel.
Interfering cog removed.
Father and son show how it’s done.
Part 1
Part 2
Part 3
Please don’t read further if you are not a spoke engineering nerd.
One of the best examinations of wheel physics and spoke performance is a 1996 paper by Henri Gavin, Bicycle Wheel Spoke Patterns and Spoke Fatigue.
Its findings and predictions stimulate numerous revisits every year in forums and exchanges that explore the principles of bicycle wheels. On page 11 he refers to spoke testing conducted at Stanford in 1984 and 1985 by Wheelsmith. My brother Jon and I were developing a superior spoke at that time and the convenient and friendly presence of Stanford in our neighborhood led to some ground breaking research. Spokes were tested and some conclusions reached. Recently, Charles Ramsey speculated what would be the ideal spoke design, one in which breakage at the elbow was as likely as at the thread.
Spoke surface texture and microstructure.
While many of you admire and some ride wood rims, nearly no one has seen how they are made. So, you can imagine my pleasure when Antonio sent me a 20 minute movie in which he and his father, Giovanni, demonstrate their craft.
Watch some familiar wood working machines and some built 100 years ago, expressly for wood rims. There’s nothing like true artisans with the tools of their trade.
We’re grateful to Daniele Di Lodovico, a doctoral student at the University of Washington, for his partial translation of the Cermenati’s description. Kristina Hjertberg applied the subtitles.
In this three clip session, you’ll see the basic method for building a Ghisallo rim. Naturally, the details vary from rim to rim. Lately, the highest performance tubular rims are made from equal thickness, 4mm laminations with cotton cloth between each. These are thin enough to bend dry.
Of course, you can’t see the decades of experience that guide these masters in selecting wood, orienting and matching grain, wetting and drying laminates, and shaping the final rim. It’s as non-automated, a hands-on process as you will see: the handiwork of a family of dedicated artisans, in the name of cycling. Each rim contains a generous portion of their life and wisdom.
Just click each link, Part 1, Part 2, and Part 3, and enjoy!
[Note: this is #9 of a series of 20]
Back in the 1970’s, aluminum nipples were rare. We had superlight tires (<200g), superlight rims (<260g), and superlight spokes (butted 15 ga), but no one thought about aluminum instead of traditional brass for nipples because the weight savings is small (~20g/wheel) and a nipple failure is just as bad as spoke breakage. The only aluminum nipples available were made from inferior alloys and didn’t impress serious riders and builders.
In the 1980’s, companies like DT and Wheelsmith set their sights on making high quality aluminum nipples. In Wheelsmith’s case, the solution was four-fold. One, use 7075 aluminum, which has superior hardness. Two, make the nipple with 30% more threading so the chance of stripped threads is reduced. Three, forge the nipple rather than machine it to shape, to increase metal integrity. Lastly, rely upon recently developed thread compounds (Spoke Prep) to reduce friction and prevent corrosion, both a much greater concern with aluminum than brass. Read more →
[Note: this is #8 of a series of 20]
We refer to the World’s predominant spoke shape as “J-bend,” which couldn’t be more self explanatory. What escapes discussion is the precise geometry of the bend. For low end wheels and short distance riders the only concern is whether a spoke can be attached to a hub quickly and stay put in service. The situation is different for high end wheels and competitors, where every effort is made to minimize weight without losing strength.
Besides punctures, spoke breakage is the most chronic headache for wheels used in competition and serious training. The majority of spokes break at the elbow, hence our concern with the geometry. A broken spoke means instant, major wheel wobble and the repair becomes elaborate if both tire and cassette removal are required. You might be able to ride home but one brake will need to be open to a point that renders it useless, an unwelcome distraction on any outing. In a worst case, the wheel won’t rotate without contact with the frame or brakes often knocking a racer completely out of contention. Read more →
