Among excellent makers of allen wrenches (think: Bondus, Allen, PBSwiss, Pedro’s, Park, Wihus, and others) only one has addressed engagement geometry like external socket wrenches have.

Hex screw on left. Allen screw on right.

Historically, allen screws arose for embedded fasteners. The wrench inserts into a fastener rather than surrounding it. But the hexagonal interfaces have similar limits. In order to transmit maximum torque to a fastener without deformation drive shape was devised for external sockets, often known as “flank drive.” That name belongs to Snap-On, a socket drive pioneer but you’ll find such drive geometry everywhere today. Read more →

Two exciting classes are on offer at PT Cycle School. June 24-25 is Wheel Building 2. June 26-30 is Bike Mechanics 1. Hard to imagine a more beautiful place (Port Townsend) or a better class offering.

Mechanics 1 is taught by Tori Bortman, author, experienced teacher and mechanic from Portland. Class is limited to 12 students who enjoy wonderful workstations (including EVT lift stands), full tool kits, and plenty of hands-on. It’s a fast paced program, not for the casual. Elevate and make current your bike mechanical skills. The course is $1,000 and scholarships are available.

In the Cotton Bldg on the PT waterfront.

PT Cycle School is a Washington licensed workforce training and education school. This curriculum is a match for that offered at other fine bike schools across North America.

Wheel Building 2 is my project. We ran a similar, advanced session at UBI in 2018. It was very successful but this time will be much more hands-on. Each attendee (limited to six) will build a wheel that’s not hugely distracting (I supply parts or not) and we’ll discuss all aspects of the process—thread compounds, lacing setups, alternative stands (P&K stands for all), tension output and graphing. stressing the structure, etc.

Me and co-presenter, Jude Gerace, at UBI.

Design and physics, the main focus of our Portland session, is valuable (material science, rim stiffness, nipple interface, tire fit and dynamics, tension and fatigue, MOI, calibration, etc) and we will cover that too. You’ll also get an in-depth, hands-on with spoke cutting and threading. Suggestions welcome as each of you brings unique perspective and career objectives.

Two full days, $300. I am not aware of any commercial offering of this level of wheel building. Such knowledge is usually only shared in one-on-one mentorships within workshops and manufacturers. It’s not generally available.

There are still spots available for both. If this late timing works for you, don’t pass it up!

Torque—the rotational equivalent of linear force—enhances the integrity of mechanical assemblies when applied correctly. Torque values are integral to engineering design as they apply to fasteners at joints which can be a structure’s weak points. Knowing the intended torque makes us smarter, safer mechancis.

Read more →

October wheel building class in Port Townsend,

2 days + 6 rims and hubs + 192 spokes + 1 jolly teacher + 6 determined students (with an age range of over 60 years) = six excellent wheels and six future master builders!

Thanks to all who contributed to another successful Port Townsend Cycle School program!

Wheel building is booming, though it’s rare to see evidence in the cycling press. I’d call it a work in progress, rather like craft brewing back in the day. Pioneers were scrappy and uncertain. When they first appeared, the big brewers knew it would be sporadic and limited (college towns, resorts). They actually got murdered over several decades and now craft brewing carries a large percentage of that market. This seems to be happening with wheel building. 

Today most small builders are in likely cities (Portland, SF, Seattle, Boulder, LA…) but their global rise (UK, AU, NZ, EU…) shows it’s not a local trend. Your area may be barren but many successful builders are elsewhere. Check these, among hundreds more:

• Magnetic Wheel Co. (Portland)
• Monument Wheel Works (Seattle)
• Diablo Wheel Works (Pacific Palisades, CA)
• Ergott Wheels (Islip, NY)
• Joe Young Wheels (Granbury, TX)
• Noble Wheels (London)
• Wheel Tec (Alkmaar, NL)
• Melody Wheels (O’Connor, AU)

Not personal recommendations (but all excellent). The more you look, the more you’ll find.

If you are contemplating getting underway I recommend exploring two questions.

Where Am I?
You may plan a strong web presence but your immediate scene is your most important asset. Local riding is a key element in your opportunity.

© Sugar Wheelworks (Portland)

Put aside personal preferences and experience because, as a wheel builder, you should welcome, understand, and whisper to all forms of wheels. Can’t do too much research and preparation to cultivate your local community.

Who Am I?
There are many types of builders. Wheel construction seems pretty straightforward but those who succeed do not share one approach. One science I hope, but not one style. Who are you? Understanding your style helps direct your effort and avoid confusion.

1. Hobbyest
Handy with tools, good with gear, likes self sufficiency, finds building fairly easy, builds own and wheels for friends and family. Not so keen to make a simple task complicated or dramatic.

2. Social
If you’re gregarious, wheel building can bring quite a range of human variety your way. Creating a business around the needs and exploits of riders is attractive to customers. You’ll want a welcoming workshop with plenty of ambiance and regular outreach.

© gravy wheels (Novato)

3. Nerd
Many an engineer type is drawn to building and customers, in turn, to them. Emphasizing tech with gauges and instruments, sharing spreadsheets and charts, teaching the “how” behind wheels can be a central theme if that is your drift. But it is not necessary to reek of tech. Performance minded customers need to trust but rarely require knowing all about the science.

© Cutlass Wheels (Baltimore)

4. Artistic
Wheels are beautiful and there is room for plenty of self expression for a builder. The bar is very high for visual compatibility with the bike, high finish of components, and unity of design. Aesthetics are an ever changing scene, rules flex, styles evolve, and builders help drive change. We’ve all noticed what fixies combine on machines so basic they simply showcase wheels.

© Roues d’Olive (Fully, Switzerland)

We are combinations of such types but discovering that inner builder is key to separating your offering from vague and mainstream options. Riders seek custom building for more than alleged benefits of value or performance. They want to deal with a real person, not just an “add to cart” button. There is no “better” style but the clearer yours, the greater authenticity you broadcast.

Authenticity attaches to wheels, gives them karmic power riders remember for years. Authenticity of our prized possessions adds meaning to our lives. That’s your ultimate product as a custom wheel builder.

Go for it and please share your experiences with others (and me :-)!

Let’s talk rotating weight. Rotating weight is a big issue for wheel builders. Why? We make choices that determine wheel weight, its total and location. Builders must understand this topic.

Rotating weight directly affects inertia, so the topic is really inertia. Inertia is the resistance of a mass to acceleration. Moment of inertia (MOI) characterizes this resistance and depends on rotating and non-rotating mass. Builders should be measuring wheel MOI.

I’ll show you how to measure moment of inertia (MOI), plus I’ll share a spreadsheet to shortcut the math supporting MOI measurement and its effect on riding. Plug in numbers and get usable wattage estimates. Read more →

On the eve of this very non-commercial weekend (Easter 2017) let’s reflect on a personal aspect of wheel building. Much time is spent on performance, component options, tension strategy, and rider relations but building wheels is more a lifestyle than economic choice.

For many, the atelier (workshop of an artisan) is home. Wheel building succeeds in no space at all (think, back seat of a support vehicle) but for most their atelier is a spiritual place. So much time spent deep in the maize of tension and trueness, work space is an integral part of the process.

Here you share aesthetics and design priorities with visitors. There is no one way to do it, each of us is different, but every thoughtful wheel building space meets needs we all share: simplicity, tools at hand, tranquility. While building is a straightforward engineering process, the work is largely cerebral. The atelier is both a stage and a tool.

I’ll never tire of other wheel builders’ spaces and can’t help but fantasize what work there might feel like. One such belongs to Olivier Lambert whose “Roues d’Olive” is deep in the Swiss Alps in the picturesque town of Fully.

Village below, riding above!

Just imagine the challenging and spectacular scenery he enjoys year around! And when it’s time to work, the atelier provides a serene, almost film set-like tranquility that must help calm one down after a lively dirt session!

Tidy, simple, quite nice.

Rim decals are clever, initials with topographic lines.

Lacing often involves ingenuity as there’s precious little available on which many builders agree. Olivier has a nice desktop cutout to support the rim. A camera tripod provides a steady, adjustable hub support. Good idea!

Upholstered and professional.

For some, an ideal atelier includes a dog bed or headphones to block out industrial noise. Lucky to live in a riding paradise. May customers find you (but not to the point there’s no time to ride)!

[all images courtesy of Olivier Lambert]

A good primer on basic wheel building is hard to find. I’m regularly asked to create one since the articles in our library address wheel building subtleties, concerns past the initial challenge to assemble a rideable one.

Here is part of the solution, four articles (10k words!) written in 1986 for BICYCLING magazine. Many of our present day concerns (extreme dishing, carbon fiber rims, tubeless systems, disk brakes, etc.) are missing. The fundamentals have not changed so this series is still useful.

Dour but persistent!

It is a good, basic primer on wheel building that is still relevant 30 years later. After all, the tensioned wheel remains at the heart of cycling and the laws of physics are unchanged.

The link is here. Hope you find it useful. I am working on an updated version of this instruction but it keeps getting delayed. Go figure.

Removing tubular tires should be easy. Getting the tire off the rim should not require gorilla strength.

Over the past few years a new issue has arisen. Pulling tubular tires from carbon fiber rims can cause delamination of the rim bed. Creepy, to say the least. Is this normal? What is going on? What to do?

Key points:

Carbon delamination – please, no!
No carbon rim maker wants to hear about structural delamination during tire removal. Every design effort is made so it cannot happen, as it is impossible with aluminum rims. We all have the same objectives. Under normal circumstances, the inter-laminar carbon layup strength is greater than contact cement on the surface.

Is the delamination important?
Plies (layers) of carbon cloth are extremely thin. Departure of several plies is visually dramatic but may not be a structural problem. It all depends on the design. The rim maker is your only reference. Hopefully, the departed plies are sacrificial, intended to be rugged and expendable.

Gluing is improving
We are seeing a growing appreciation for tire gluing integrity. More than ever, mechanics are using best practice for achieving strong bonds. In the past, when glue integrity was mainly a concern for high level road racing, technique could be less rigorous. Cyclocross, in particular, sees weird rim-to-tire combinations (where bed and tire form do not closely match), suffers water contamination (weakening bonds), and uses very low tire pressure (lower pressure = less tire grip to assist the glue). CX gluers are doing really good bonding.

How to minimize risk when removing a tubular
First, deflate the tire. Air pressure makes the tire grip the rim. Not enough grip to ride without glue but enough to interfere with removal.

Next, try and pry a small section of tire free. Use all your thumb and grip strength. If the tire is properly glued, you will fail. Well glued tires cannot be removed by hands alone. Still, give it a try. After working a 10cm section on one side, flip the wheel over and try opposite. With luck, some of the tire base tape will begin releasing from the rim.

Even strong hands may fail.

You’ll then need a narrow pry tool, such as a slotted end screwdriver, to push into the glue and separate the tire from the rim. Your goal is to push the screwdriver (or equivalent) all the way through between tire and rim, from one side to the other. A steel tool like this can damage the rim or the tire. Use it gently, pushing carefully, wriggling small amounts, separating the tire from the rim in tiny bites.

Careful screwdriver use.

Hurry, the driver is through.

Once you achieve tool insertion, replace the slotted (sharp end) screwdriver with a round, Phillips type. My best luck is with a blade about 6mm (1/4″) in diameter. A larger diameter dowel works but the rim and tire prefer the small steel shape. While seated, place the wheel between your legs, with the screwdriver handle in your dominant hand. I am right handed, so here the screwdriver handle is on the right.

Rotate the handle clockwise while you pull the driver towards you.

Orient the wheel so the screwdriver is at the top. Pull the driver towards you with both hands while you rotate it clockwise (viewed from the right side). Pulling while rotating advances the blade towards you, rolling against the sticky tire bed and skidding against the smoother rim.

This rolling requires a strong turning hand (right for right handers) and a firm pull on both sides. The tire bond is no equal for this rotation. The tire will begin to separate from the rim as you pull and rotate.

You can also use a dowel but the screwdriver blade offers less resistance and a better separation angle. The glue joint is more susceptible to the small radius of the metal driver.

You’re inducing a glue joint failure and the angle of separation is better for the small rotating blade than a larger rotating dowel. We’re inducing a cohesive failure with glue remnant on both rim and tire, handy for future gluing.

As soon as enough tire is separated, pull the tire from the rim. Pull in the plane of the wheel so the tire is doubled over as it leaves the rim. This minimizes base tape separation as you pull it from the rim.

Back to our carbon rim problem, Using the small diameter metal rod induces cohesive failure and minimizes the chance of rim delamination. The final tire removal (over 50% of the circumference) is done without the metal rod, just arm strength. Doubling back the tire as it peels reduces delamination forces.

More than a few mechanics note that heat aids tire removal. At 70C (160F) rim cement is liquified. At 40C (100F) cement is substantially weaker than on a cool day. Using a heat gun to warm is impractical. A wheel is large and sheds heat. At least appreciate this principle and let wheels come to the highest available temperature before pulling tires.

Throughout tire removal, proceed slowly and watch the tire carefully. Stop if anything does not proceed smoothly. Some tires will disintegrate upon removal but it’s rare except for limited use track tires.

There is much to tire mounting that you must know. Demounting is not the opposite of mounting. Great instructions are available in many places: mine (here and here), Calvin’s, and Chip Howat’s scholarly works, among others. Gluing tires is done thousands of times a day and each job carries immense responsibility for rider safety. Learn your stuff and be part of the reason cycling is known as a healthy sport.

As ever, practice is the best teacher. Try different techniques, pester experts with questions, listen to all opinions, and develop dependable techniques. There are too few tubular gluing guru’s. Please join this club!

Since wheel sages know tensiometers are optional for the highest levels of building, let’s ask, “Why use one at all?” After all, some are substantial investments.

I co-introduced the first consumer tensiometer in 1985 and still sell them today, so I have a bias (or 2) and some perspective.

What do they do?
Experienced builders are right, a great wheel does not require a tensiometer. Even for beginners, everything you need can be learned by trial and error.

Using a tensiometer reduces the chance of incorrect spoke tension, the most common fault of wire wheels. Both the average and the distribution of tension must be in a narrow range for components to blend optimally into a single, rugged structure.

Squeezing spokes, plucking them, and feeling nipple turning resistance are ways to monitor tension besides a dedicated measuring tool. A tensiometer prevents misinterpretation from:
–  Thick spokes feeling tighter than thin because they are stiffer to squeeze.
–  Nipples suggesting higher tension if they resist turning due to corrosion or lack of lubrication.
–  Material and geometry of rim holes and nipples greatly affecting twisting friction.
Tensiometers can see through all of this, a boon for beginners.

A training tool
More than enabling appropriate tension, as you see tension numerically, associations form without conscious effort. You become trained to sense tension just as a heart rate monitor trains you to know your rate.

After thousands of observations, wheel tension becomes more and more intuitive. Rim models, tensions with various spokes and nipples, time to finish, and eventual long term outcomes, all become associated. This mental landscape is best built with a tensiometer and as experience accumulates your expertise grows. This intuition separates masters from learners and enables very fast builds.

The conversation
Since numbers are better than adjectives like “tight,” “not so tight,” “really tight,” etc.; component makers, builders, journalists, and riders can exchange ideas and discuss experiences with a shared numerical language. Kilograms of force and newton meters enable instruction and conversation. This ongoing discussion shapes product development and wheel designs. Without it, the cycling world would be more random and hazardous.

Reassurance
These days it is best to show you use a tensiometer and have respect for the subject. Sure, it’s part marketing but people tend to make snap judgements, especially when trust is involved. There are so few tools in wheel building despite its engineering feat. Callouses and name dropping go only so far to establish credibility. Modern consumers will often defer to a very neat and well equipped workshop over a spartan layout in spite of good reviews.

So remember
There are two levels at work in your building. One is the wheel before you, wanting to be the best it can. Two is the learning brought by experience. Building your intuition for component, especially spoke, behavior is an immense treasure – the key to speed, a reservoir of patience, a resource for advising riders, and a stimulus for design insights. No wonder many builders…