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.
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:
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)!
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…
Name a spoke-hub connection that is entirely overlooked (except by veteran mechanic, Jim Langley). Of course, the Z-bend spoke, also known as dog-leg or S-bend. An abrupt left and then right bend enables it to connect with a hub drilled for J-bend spokes, bear full tension, and last as long as a J-bend.
I rode a 1951 Raleigh 3-speed for years, equipped from England with Z-bend spokes front and rear. Hubs were drum brake Sturmey’s with internal 3 speed for the rear.
Clean, economical, proven.
On the smaller side of the front hub spokes have an extra kink as the trimmed end exits the hub hole; an unnecessary feature to make coming loose even more impossible than it already is.
Good for steel or aluminum hubs.
The trouble is making close-spaced bends in stiff spoke wire. 14 gauge is hard to bend and it’s nearly impossible to place a second bend near enough to the first. High spec pliers and a vise are no use. A dedicated tool is needed but the last on record is the Eldi repair plier described by Jim:
Eldie spoke plier. © Jim Langley
The potential usefulness of this sort of tool boggles the mind. For clever shops, for ride support (charity, gravel, fondo, tri), having the means to swiftly create a reliable substitute spoke without a 30 lb spoke machine is awesome. The Z-bend shape holds full tension for a lifetime and can often be inserted without removing cassette or disk. What convenience and economy!
Z-bend made a brief appearance in the ’80’s and ’90’s with Hoshi bladed spokes. The obstacle to truly aero spokes is getting the blade section through the hub hole. Hoshi offered theirs with Z-bend ends.
With Hoshi, a standard hub could hold wide, bladed spokes. Elbow outside not standard but a bit laterally stronger.
Once a Z-bend has been pressed into shape on a hub like that above, it will not look like a freshly pressed spoke. The fit is easy and thumbs can do the shaping.
Top is an ACE (0.9mm thick) blade with new, Z-end. Below is the Hoshi with end shaped by the wheel above.
I began buying tools that might work and finally found one. Similar to the Eldi of yore, it’s produced by an RC Airplane supplier to make control rods. RC planes don’t use wire as thick as 14g but this plier can do it. The others failed.
9″ long for power, huge pivot to maintain alignment, 13 oz of hardened steel to be unfazed by stainless.
Here is how it works:
Spoke inserted.
Handles squeezed (use 2 hands) and spoke bent.
There’s that golden shape!
Benefits:
(1) Inexpensive, we sell it for $21.95 (MSRP is $29).
(2) Compact enough to live in any versatile wheel shop or with a mass ride support program.
(3) Overbuilt, so indefinite lifespan.
Note:
(1) You will need a wire cutter, to first trim the right length from a spare spoke,
(2) While compound action or longer handles would make it a one-handed task, the cost would rise and the tool weigh more.
(3) This particular Z shape is ideal for 2mm thick flanges, perfect for cheap and steel hubs. Better hubs have 3mm flanges. For these, the bend is good for elbow-inside fitting:
For elbow-outside, just fit the replacement and bend the spoke down towards the correct angle. The same as we often do with normal spokes. Has no effect on integrity or longevity.
Here is a perfect “sleeper” tool. In time of need, when everyone is resigned to a DNF, whip out this baby and be a hero. Embrace time-tested solutions on your quest to become a complete builder. Oh yes, plenty of practice on junk wheels first!
Twice reminded of a very important but often overlooked subject: first reminder – mention on the Classic Rendezvous group of a recent instructional video about mounting tubular tires by Rhys Bateman (courtesy of hackcycling). Second bell-ringer – the upcoming USAC Mechanics Clinic (sold out but there’s always 2015).
Why these, why now? Glued on tubular tires were the original pneumatic tire. But 30 years ago, they all but died out except for high level racing. Clincher tires became standard and, despite numerous issues, none include adhesives. With this switch came a broad amnesia among riders and mechanics about vital tire gluing rules.
End of story except tubulars staged a stunning comeback powered by the carbon rim. Making light, inexpensive, and safe carbon clinchers is elusive. A tubular carbon is not. The weight and aerodynamic benefits of carbon (not to mention marketing bling) pushed tubulars back into the market (they never waned among professional racers). But there is a scarcity of knowledge about mounting them.
Most of us never have the opportunity to learn from mechanics of high level teams about rules for gluing. One of the single most important missions of the annual Mechanics Clinic is instilling a combination of fear and expertise into attendees about tubular gluing. The techniques they learn from others, read from product box tops and glue containers, may work locally but actually be dangerous under many conditions. If tubular riding customers are mostly triathletes (less descending and extreme cornering) or track riders (no brake heat), then your technique may seem adequate.
Beloki (leading) has lost his rear tire.
When a tubular leaves a rim, the rider crashes. The fall is sudden, unrecoverable, and injury inevitable. Other riders are also at risk. However, think of the various perspectives. A rider suffers such a fall, hopefully not season-ending. It’s miserable but riders fall for other reasons as well, so it feels like a risk of the game. However, if you are the mechanic who glued the tire and the glue job was flawed (easy to detect), you have more than abrasive wounds. Depending on the situation (think: Worlds), this can be a career ending event, a misery never forgotten. Ironically, the rider might be less of a victim than the mechanic. Here is where our concern really becomes acute.
The World’s Best instruction for tubular mounting and all the related principles is a direct outgrowth of the Mechanics Clinic. An early attendee was Chip Howat, Emeritus Professor of Chemical Engineering and former Director of the Kurata Thermodynamics Lab at University of Kansas. As he joined the ranks of race mechanics (part time of course) a question arose, “what is the most urgent chemical or thermodynamic issue in cycling?” The answer was a resounding chorus: tubular gluing. There are lots of tire-induced crashes and a dozen recipes for gluing. What is best?
Glue don’t fail me now (© Cycling Weekly
Over several years, Chip supervised lab study to sort this out. Now the world of cycling has data and authoritative prescriptions for gluing all types of tires to all types of rims. Here is the archive. Click “Bicycle Research” and “Online Articles.” Illustrated demonstrations are also helpful but only if they are consistent with the engineering. Two come to mind: Calvin Jones (Park Tool) shows some great techniques to ease the procedure. And Rhys Bateman’s demo is well informed and presented.
One take away tip? Use a brush to spread the glue on the rim and on the tire bed (they both need it). Toothbrush, acid brush, no matter. You paint the glue to textured surface. A brush does the job best.
Inexpensive acid brush.
Oral-B at work
Let’s finish with two last points:
1) Tire gluing is inherently flawed. It cannot work under all conditions. So, flawed gluing is NO option.
2) Sanding rims can be miss interpreted. Adhesives and sanding are not related the way most think. It is critical you know this. Really!
Gluing Theory
The goal of gluing is to attach a tire so securely that no combination of extreme conditions can pull it off (heat, sideways skidding, panic deceleration, partial wheel deformation, tornados, etc.). At the same time, we insist the tire can be manually removed in case of a puncture or wear. These are mutually exclusive. No such thing. Result? Under rare and unwelcome conditions, a properly glued tubular will come off. The only solution would be high temperature epoxy, so strong that removal requires ripping the tire to shreds. No one is ready for that.
Do any of you question my assertion that tires will come off? An imaginary scenario to prove a point:
Start a mountain road stage from a picturesque village spread along the alpine route. Begin with a controlled start, a parade for the locals in which a race vehicle heads the peloton at low (20-30kph) speed. Make this control section a 5% descent out of town. At 5k, the pace car pulls off and the peloton starts racing, descending for 1km more accelerating quickly. At 6k, we insert a steep hairpin turn. Riders jockey for position, take the corner aggressively on over heated tubular wheels. The whole peloton crashes at once. Tires flying everywhere.
Need more motivation?
Sorry, gruesome. What do the experts say about this catastrophe? First, the promotor and the course designer are hung. Anyone schooled in the basics of bicycle racing knows that tubular tires cannot survive the course described. Race courses are intentionally designed to produce safe challenges for competitors. Course induced crashes rare because we know the limit of tubular glue and design races around it.
However, this presents special issues for recreational “competitors.” Respect for weather, traction, heat, etc. are part and parcel of our collective space. And mechanics cannot be under gluing tubular tires. Ever.
Sanding Rims
Read Chip’s discussion of sanding and tire gluing. Data! Notice aluminum and carbon beds. Answers are there for you.
Be aware that sanding does not improve adhesive strength. The ONLY reason to sand a surface prior to bonding is to clean it. There are contaminants that resist all solvents. The only way to guarantee 100% cleanliness is to lightly sand the surface, removing contamination.
However, the sanding is counterproductive if its debris (may be microscopic) is not removed. Use a strong solvent (lacquer thinner, acetone, MEK…beware, all highly flammable) and a perfectly clean, white cloth or towel. Wipe, turning the cloth, until there is absolutely no color coming off the rim. Now, until airborne contamination begins landing, your rim is ready. That’s why we try to store tubular wheels with a tire aboard. Even a flat, throw away will shield the rim bed from airborne contamination.
It is NOT a matter of removing shine. Perhaps a useful target to assure sanding is minimal but shine is not the adhesives enemy. Rough surfaces can be repellant to adhesives and shiny ones permit 100% strength.
Oh yes, for cyclocross gluing, conditions are so different, you deserve advice from specialists. In the meantime, hope you know more about tire gluing. For many of us, tubulars remain the most rewarding, exciting, and desirable ride. In spite of all the scary stuff above, the tires of our forefathers are still pretty damn sweet.
Do not be shy about posting your opinions on this subject. No topic is a closed discussion. We are all learning!
