brian's law

After my September mention of the so-called Brian’s Law, Thom (many of you may remember Thom from HubBub a few years ago) wrote asking what it was.  I was a bit surprised we had never discussed it during his 2 ¹/₂ year tenure here, but Thom has a pretty good head for these kinds of things so I’m sure he’s right that it never came up.  The drawing of my cable guide in my last post brings up the subject again; as for some it may raise a question of determining how to illustrate the profile of the mating surface where the down-tube (a cylinder) intersects the guide.

If you cannot tell by now, this post has nothing to do with bicycles, but only orthographic projection of intersecting cylinders and a related technique used in engineering drawing.  It specifically refers to a technically incorrect (however practically useful) shortcut I discovered in college.  If this fails to interest you, consider not reading any further, ‘cause it ain’t gonna get any better from here.  I promise my next post will be more bicycle related.

First off… no, I did not name it.  Some classmates in college did.  (Incidentally, I didn’t come up with the title Shimergo either.  I applied it only after others began to universally refer to my article that way when passing the hyperlink around, nearly 10 years ago.)

Secondly, it’s not a law.  It would be more like a rule-of-thumb shortcut, but in fact it is incorrect.  As far as I can tell however, it remains practically useful under specific conditions.  For illustrative purposes only, it works extremely well.

Third… well, if you’re still reading, you probably want to know what the #&@% I’m talking about:

Orthographic projection is a drafting technique commonly used to indicate the shapes and dimensions of a complex 3-dimensional object, including architectural plans.  It consists of six principal views of course:  top, front, right, left, back, and bottom.  As a general rule the fewest number of views necessary to effectively communicate all relevant information should be used.  Three is probably most common, and two is often adequate for simple items.  More than three is perfectly acceptable if required, and additional views, at oblique angles, can even be defined to ease communication – although that would no longer be orthogonal, but instead auxiliary projection.

It is important to remember that all perspective is removed, as depth is defined entirely by an adjacent view.  That is, each individual view is a parallel projection of an object’s defining features, as perpendicularly viewed on its respective side, onto a 2-dimensional plane.  This is useful of course because paper and computer screens are 2-dimensional mediums.

What is handy about orthographic projection is that objects, such as endpoints of lines, centers of circles, intersections, radii, etc. can simply be transferred (projected) from one viewing plane to another.  If done correctly, all information can be gleaned from what appears to be very little at first.  A fine example of this can be found in these two fun exercises,

where you are asked to complete the illustrations.  In case you wanted to try your hand (after printing the images and using a pencil) without knowing the answers, here is the first solution, and here is the second.

So, how does one orthographically project the intersection of two cylindrical objects?  What is taught, can be universally applied, and is technically correct, uses your own points created along the curve by dividing the curve into known segments, and projecting them into the plane you require.  This incredibly tedious (especially by hand) technique in fact can be applied to any object, and is especially useful for complex curves, or illustration of cylindrical and elliptical objects intersecting with any surface, particularly at an oblique angle.

But what if it’s just a simple situation of real cylinders, of differing diameters, assembled in a true perpendicular intersection?  Maybe these constraints sound excessive, but I have found it to occur rather commonly.  It is very rare on a typical bicycle frame – maybe the top-tube intersecting with either the head-tube or seat-tube, and of course the seat-tube or down-tube joining the bottom-bracket shell, but coping bicycle frame members generally doesn’t require accurate representation of what the copes will look like projected orthographically.

Given a problem like this in class once, and being lazy when it comes to overly tedious tasks, I opted to spend my class time instead trying to develop a shortcut.  What occurred to me was the projected curve should always be the same radius as the larger of the two cylinders.  Now, before you say, “that’s overly simplistic,” remember that I already admitted this is incorrect.  Then, go try it.  It does work.  It may be incorrect, but it works to a tolerance well within any reasonable expectations for practical use.  Also, remember there are rules to this, and it will only work in a specific situation:

1. The cylinders must be different in diameter.  Cylinders of the same diameter project an “X” onto the view plan – one indicator that the “law” must change as the cylinders approach each other in size (thereby rendering it a non-law).
2. The cylinders must be perpendicular to each other relative to the view plan.  Any variance from perpendicularity immediately illustrates why this shortcut idea is technically incorrect.
3. The cylinders must be true, and not elliptical, in cross-section.

It was a customer of mine, a professor here in Cleveland, also named Brian, who finally figured out why the projection is actually not an arc with a radius equal to that of the larger cylinder.  The projection is hyperbolic, and without constant radius at all.  This seemed obvious only after he eventually pointed it out.  The curve does however occur so near the apex, well inside the hyperbola’s focal point, that it indeed appears to have a constant radius, which effectively approximates that of the larger cylinder.

Finally, as this projection is really only used for illustrative purposes, there seems to be no reason not to apply this non-“law” to accurately portray the visual appearance of such an intersection.  One might argue using the point I tried to make regarding the physics of pendulums.  I cannot imagine discouraging teaching the truth first, but use of effective techniques, however technically incorrect, seems appropriate for sake of efficiency in practical application, especially for illustrative purposes only.

If this wasn’t enough fun, here’s one to think about for a little while, provided by the owner of the Univega (and cable guide) featured in the previous post:

Given three circles of different diameters, all co-planar but arranged any way you wish, draw adjoining tangents among them, and continue the tangents to their respective points of convergence.  Note that the three points of convergence are co-linear; that is, while only two points are required to define a line, all three of these rest on the same line.  This is true.  Prove it.

A hint was provided: although all objects (circles and lines) exist in the same plane, the only known solution required reference to the third dimension.  Again, note that the circles can be any diameter (as long as they’re different) and can have any possible arrangement.

If you figure it out, please do not send me your solution.  I have not solved it, although telling me you did might provide some motivation to get cracking.

top-mount cable guide

Last June (2009) we took on a project restoring and upgrading an old Univega.  (Yes, I know the time it's taken me to write about this is pathetic.)  The bike required the usual changes, like respacing the dropouts, but the only real challenge was converting the down-tube top-mounted shift levers to integrated controls at the brake levers.  This usually is not an issue, as most down-tube levers are either side-mounted to bosses, or clamped on using a strap.

Since someone has already asked what the mounting stud is, I have modeled it. This is what the brazed-on stud looks like, with the lever mount removed from the down-tube.

We saw three possibilities: to use clamp-style cable guides, to remove the boss and braze on new ones, or create a cable stop that uses the existing stud shown in the model.  The clamp style guides work great, but would be inelegant, leaving the exposed stud unused.  We also did not care to deal with damaged paint, from removing the existing boss and installing new ones - especially since the original paint was in excellent condition.

I opted to create a new cable guide, using the existing boss, and with adjustable housing stops.  It's hardly profound, but it works great and, for the most part, looks as good as the alternative options.  Both its mating with the protruding boss, and its engagment with the curvature of the down-tube hold it straight.  Of course the M5x0.8 button head fastens it to the stud and, recessed, approximates the curvature of the new guide.

If I were to do it again, I would probably remove a little more material, making it lighter (it's not heavy as-is) and... well, fancier.  Maybe chamfering the square ends, and milling some excess away from the top and middle.  I have seen incredibly few top-mounted shift lever like this, but on the off-chance that someone has one, seeks a similar solution, and could benefit from a launching point, here's a drawing of my original.

le' hubbub award

No, it's not our award, neither given by nor received by us.  I wonder however if it might have been named after us? 
http://www.athenscyclepath.com/HubBub.html
I just discovered the reference this morning. Normally we are wary of finding the name HubBub (or word hubbub) used elsewhere in the bicycle industry.
This time... maybe we should consider the possiblitity of having found an honor:
" 'The Hub Bub' Award is Given by Cycle Path in Recognition of Excellence and Commitment to Bicycling..."

In all honestly, I doubt very much any association was intentional, but it's interesting nonetheless.

pendulous lesson at cwru

Yesterday, for the second time, Diane and I filled a request of Professor Isaac Greber’s: give a 70-minute presentation to a class of his students at Case Western Reserve University about bicycles, their place, progress, and possibilities with regard to commuting and urban transportation issues and solutions. I don’t consider the topic a prominent area of my expertise, but Diane is usually a bit more in touch with the social aspects of our sport, so we pull it together somehow. Dr. Greber is a long-time client of ours, rides a custom Seven Axiom Steel, and is one of the most thoughtful and pragmatic people I know. So for now we will refrain from questioning his judgment in selecting us for this class discussion, and his expressed satisfaction with the results. Besides, I learn something new with nearly every encounter and, hard as I try, I have yet to win one of our many good-humored debates. It’s not always that I’m incorrect (although it’s been known to happen all-too frequently)… as much as he’s brilliant at finding ways to be more correct than I!

After class we hung around in the classroom for an additional hour and entertained Diane with our banter. (This often requires a chalkboard, and is the reason I insist on always having one in my workshop.) Dr. Greber is a professor of engineering, so most of our chats naturally involve math and physics. Yesterday’s was no exception, as we discussed the place, and appropriate application, of approximations in engineering. One of my initial points was how challenging it can be for a budding engineer to accept that an absolute solution may not always be possible, let alone that approximation may indeed be most appropriate. It seems engineers are often thought of as “precision oriented” thinkers, but I prefer to think of experienced engineers’ methods as “optimization oriented” thinking. We started out discussing what a few of my college classmates and teachers referred to as Brian’s Law. (Maybe I’ll write about that another time. For now, it will suffice to say it involves the orthographic projection of intersecting cylinders.) We then moved through another project I did involving changing chip-load on a slotting cutter as it is plunged into a shaft. (Does intersection of cylinders seem a common theme?) Finally, we settled on Dr. Greber’s example of inappropriate use of approximation, and I learned something I’m ashamed to admit I never thought deeply enough about to realize on my own. He was barely into his explanation before it became intuitively obvious.

He pointed out how it is all-too commonly taught in physics that a pendulum’s period is angle-independent – that is, the time required for the bob to swing is not dependent on the amplitude (theta, angle of swing from vertical), nor the mass of the bob, but solely on the length of the rod, and gravity. The formula given is: T=2pi*sqrt(L/g), where T is the period, L is the length, and g is acceleration due to gravity. This equation is false, albeit close. In fact, it should not even be an equation.

The truth, if we are to stick with this basic formula, is: T is approximately 2pi*sqrt(L/g), for any small theta; and even then it is only accurate for minutely small swings, as the period grows exponentially with amplitude. This is a subtle but, in my opinion, crucial change when considering the purposes of teaching physics.

“So what?” you ask. So what indeed… for most practical purposes (small theta) it simply doesn’t matter and the equation applies just fine. My issue (and on this Dr. Greber and I readily agree) is with the idea that the equation is taught as fact, rather than as an appropriate application of a deeper understanding of what is really happening. Use of the equation is usually acceptable in practice, but teaching it without the accompanying understanding of a more accurate context is not.

exploding wheels

This story about Ben Delaney’s shattered post-recall Mavic R-SYS wheel is making the rounds this week, and rightly so. It's bad enough the wheel failed the way it did, but then to have a company representative even hint there might be "rider error" involved seems outrageous, at least at first. According to Ben’s version, and those of his witnesses, rider error appears unlikely but I contend, "So what if there was rider error? Errors occur all the time! Wheels should not explode!"

According to Mavic's side of the story, "the cause of the accident has not yet been determined." This is understandable from their perspective, but I still fail to see how a cracked top-tube, or a sheared valve-stem, or rolled clincher, or whatever else might have caused or contributed to the crash... I don't see how these possibilities create space for an utterly shattered wheel.

Mavic also point out the relatively obvious, "Carbon acts differently in a crash situation than steel or aluminum, but all bike components can be pushed to failure with enough force." Uh, yeah... maybe steel is a more appropriate material for bicycle wheel spokes.

It should come as no surprise that I pay little attention to VeloNews, but kudos to them this time for flipping off a major advertiser when it appears deserved. Any decent wheelbuilder can build a shockingly lightweight, smooth, fast, and reliable pair of wheels that won't explode until kicked by a horse. It's hard to win a race when you're battered and bloody, writhing in the ditch (if you’re still conscious) beside your broken, unreliable, lightweight components.

That all said, we cannot expect racing equipment to hold up under all conditions. Racing is about getting across the line first, and that means going faster than everyone else using any sportsmanlike means necessary, but it also requires finishing in one piece. We caught some flak for a comment Diane mass-e-mailed last summer during the TdF about that Specialized carbon frame that exploded in stage 13. The responders accused us of elitism, and asked to be removed from our contact list. They thought we were insulting Specialized, when we were actually sympathizing with the prospect that some consumers may not understand that frame did what it should, just like a Formula-1 car when it hits the wall and disintegrates. This is not to say coming apart on impact is a reasonable design parameter, although controlled failure to absorb impact energy may be desirable. Designing it to hold together under all conditions however would require sacrificing other criteria, more critical to maintaining a competitive edge.

Racing bicycle frames are no more designed to survive hitting curbs at 35mph than race cars are designed to survive connecting at 200mph. Wheels however, racing or not, should be designed to not spontaneously explode under any conditions.

Additionally, such equipment is for racers who have a shot at winning in competition. Much of this stuff is no more appropriate for the general consumer than a Formula-1 car is for a Sunday drive through the countryside. Your bike should help you finish first, but it first needs to help you finish - and perhaps most important, live to ride again tomorrow.

intention

I was cleaning out my home office the other day, again! It must be a more thorough job than in the past because I found so many things I had long ago forgotten about. I discovered notebooks from high school and college I didn't even know I had saved. Some are actual "note" books, a couple are "journals" we were required to write (I have never voluntarily kept a journal - big surprise) and some were jots and sketches of the countless hare-brained ideas I had. Part of the cleaning process however included digging deep into my computer files. That's where things got interesting.

I consider myself lucky to still have some floppy drives around for my computer. At the back of a shelf I found a small stack of discs so old that many had deteriorated and contained damaged files. Among the files I could read though were papers and essays written in high school. There was even a copy of an essay I wrote for a college application. It wasn't very good, but I was pleased with it at the time, and it worked.

How could I resist? This was from almost half of my life-time ago. Reading it, I could... kinda-sorta remember the criteria, or essay questions - things like, "Write about something you've accomplished that you are proud of?" and, "Discuss some of your goals during and after college." I certainly don't recall exactly what they were, but I'm sure they were something like that.

I was not yet working in a bike shop, but of course was heavily into cycling - or, more specifically, bicycles. What really threw me for a loop was how close my work is now to what I stated my goals to be in that original essay. I have to a surprising (to me) extent accomplished what I said I wanted. Even more interesting (although maybe less surprising) is the consideration that almost nothing between then and now could have been predicted. The path to get from then to now has been wildly different from what I (and others) imagined at the time, but my stated destination is shockingly similar to where I have landed.

Goals and intentions adjust of course.

The files have been erased, the discs thrown away, and there's still plenty of cleaning to do.

happy birthday hubbub

Today we celebrate the 12th anniversary of HubBub's opening. Okay, maybe we're not really celebrating (we did that 2 years ago), but we are feeling pretty swell about having survived the past 12 years (even thrived occasionally).

It was also a little over 11 years ago that I moved to the Cleveland area, and just about exactly 16 years ago that I first got a job working in a bike shop. Damn! most of it has gone by so fast. Does that mean we've been having fun? Well, it certainly has not all been games, but yes, for the most part I would have to say we have enjoyed what we do. We've accomplished a little, and learned a lot too - often the hard way, but at least we learned.

As a 2-person (occasionally 3) custom-only (non-stocking) bike shop, we have in the past 12 years:

• Occupied 3 locations (moved twice).
• Acheived top-5 (nationally) retailer status for 3 of our 4 builders.
• Designed (in 1999), prototyped (in 2000), and brought to market our drop-bar adapter for twist-style shift controls - originally for Rohloff, now for SRAM and Nexus as well - St. John's St. Cycles brought it to the U.K., and Harris Cyclery began featuring it in 2005; QBP began distributing it in 2006.
• Diane trained, and was certified, for teaching yoga in 2002.
• Built out [our current] space from scratch, in 2003, to contain 3 businesses:

1. HubBub Custom Bicycles
2. High Peaks Coffee shop
3. Daily Yoga studio

• Diane published her book, The HubBub Guide to Cycling - In fact, today marks the 12th anniversary of its release as well.
• Directed the Emerald Necklace Tour through 2004. (founded by Diane, pre-HubBub)
• Founded and directed the WooCity Century in 2002 and 2003.
• Founded and directed the Ponte-Vino-Giro weekend tour since 2006.
• Learned the nuances of brewing fine coffees and drinks, and owning and managing a gourmet cafe.
• Developed our own evolving in-house system for fitting, designing, and building custom bicycles.
• Sponsored and conducted week-long remote tech service for XOBA since 2007.
• Survived 12 years in NE Ohio, what we believe is one of the nation's most competitive markets, building a business MANY said couldn't be. (little pat on the back there - for us and other local area shops)

A respectable list, I think, even if it is a bit short (possibly even incomplete). We'll be sure to try to lengthen it over the coming years.

Finally, and most importantly, a big thank you to our families, suppliers, and especially our friends and customers for the abundance of support, lessons, business, and criticism that has brought us so far.

neutral trail

An attendee to our tech clinics this past Saturday posed the question, “How do you determine neutral trail?” I expressed my disinclination for using the two words, neutral and trail together, along with a bumbled explanation why, and the remaining audience immediately asked, “So, what is trail?” Eventually everyone (except me) seemed satisfied with my answers, but hopefully my explanations here will demonstrate why I still feel my presentation was inadequate – or at least finally convey what I intended at the time.

Why?

Perhaps the most important thing to understand here is the true magnitude of importance for using trail as a design parameter. Many of the world’s most experienced bicycle builders give only minimal attention to trail when specifying a bicycle’s front-end geometry. There could be numerous reasons for this, some good, some maybe less so. Here are three:

1. Fine handling is not only subjective, but also largely a function of a particular bicycle’s intended use. A variety of purposes and even wider range of rider experience and opinion invalidates any idea of targeting a single precise value for a design parameter (trail), especially without regard for all the others.
2. Trail is a function of exactly 3 dimensional values: head-tube angle, fork offset (rake), and overall tire diameter. While trail is a strong indicator of handling characteristics, all three of these affect how a bicycle handles, independent of the trail they generate in combination. Additionally, there are several other dimensional and non-dimensional factors to affect handling characteristics, none of which are related to trail or its components.
3. Experience has shown how it is surprisingly difficult to build an un-ride-able bicycle (with respect to handling geometry). Experience also indicates which controllable factors have the greatest effects, and within only a narrow range. For example: head angles for road bikes rarely run outside the range of 71 to 74 degrees (generally in half-degree increments). It should then be easy to imagine how a builder can quickly develop a seemingly fundamental “knowing” for how to combine head-angle and fork offset options to consistently produce an experience of optimal handling characteristics. While this builder likely knows what trail is, he or she finds little reason to care.

So, why the occasional fuss about trail? My best answer for now is… because at the very least, it is interesting to some of us. We find the complex theory and math behind why single-track vehicles operate the way they do fascinating. In fact, to me one of the most interesting things about bicycles is the dichotomy of simplicity (as the simplest and most efficient mode of transportation known – even more than walking) and complexity (our limited understanding of the finer points for how they steer and stay upright remains largely theory – explored by physicists and mathematicians). That said, interested physicists, mathematicians, and builders alike generally agree that trail is a dependable value as representative of, at least in large part, a bicycle’s basic handling characteristics. The term representative of however is unfortunately often confused with meaning responsible for.

What Is Trail?

Most simply, trail is the horizontal distance along the ground separating the points of intersection of each, the steering axis and a vertical line through the front axle, with the ground. That is, extend to the ground the axis about which the fork rotates and note the point where it strikes ahead of the tire’s contact point on level ground. The distance between the center of the contact patch and the point we just located is trail. A formula for trail is provided in the diagram. See if you can tell, by looking at the picture, what happens to trail as we adjust the variables. Does trail get bigger or smaller as the head-tube angle is made steeper, or shallower? How about as we shorten or lengthen the fork rake? As we change tire sizes?

Actually, I prefer to distinguish this as Ground Trail, and here’s why:

What trail is really meant to represent is the arm of a moment, or an applied torque. The moment we refer to here is that applied by the frictional force between front tire and the ground about (relative to) the steering axis. Effectively this is the force you experience as your bike self-stabilizes coming out of a turn. This effect is also related to what castors do on shopping carts – they roll in the direction you push the cart. (I say related because the cause and effect have actually switched places in this example.) Notice however that the Ground Trail in the picture is not perpendicular to the steering axis, as it must be to accurately represent a moment arm. This is okay for design purposes, as Ground Trail is always proportional to our true Mechanical Trail. They are not close enough to be used interchangeably, but Ground Trail does quantitatively indicate the castor effect generated by the combination of steering-axis inclination and fork offset (assuming tire diameter as a constant design parameter).

The question was, “How do you design for neutral trail?”

The issue I have with using the term neutral is that its common use implies too much subjectivity. Handling characteristics are subjective enough already without us tossing in further ambiguous descriptions. It is however common to hear references to neutral steering and neutral trail. So, what do they mean? It is because nobody seems to have clearly defined their meanings that I avoid using them. Once we have a mutual understanding of meanings, I am happy to use them too. So then, what does neutral mean?

What is neutral gear? Neither forward nor reverse. That works – it’s stationary, but it doesn’t translate well into handling characteristics. Well, what is neutral temperature? Neither hot nor cold. Hmmm… you see the problem here? We have not established exactly where the threshold lies between hot and cold. What is neutral steering? Neither twitchy nor sluggish. Same problem… too subjective. How about, neither understeer nor oversteer? That’s better, but why not just say predictable steering, and avoid all the confusion? Neutral position – neither left nor right – straight!

Okay then… what is neutral trail? I have read some strange definitions, and here’s one (roughly, from memory since I can’t recall exactly where): Neutral trail occurs when the top-front of the bicycle neither rises nor falls when the handlebars are turned. This actually never happens, but I think what the writer meant was when trail and fork offset are equal. This is certainly possible, but generally will not create favorable handling characteristics, and neutral so often refers to a “sweet spot” of perfect handling – stable but responsive, predictable but agile, etc. Even here, that sweet spot is subjective. It’s different for everyone, especially with so many possible riding disciplines with widely varying handling requirements. So maybe what was meant by the question was…

So, how do you use Ground Trail to design a bicycle’s geometry for an individual’s preferred handling characteristics?

Now we’re cookin’ with gas! The answers however will probably double the length of this already too-long post, so I will discuss overall handling geometry in the near future.

What Is Custom? practicum

HubBub Custom Bicycles Presents...

Seven Cycles' What Is Custom? practicum, and

Campagnolo Sportswear Trunk Show

Most who have purchased bikes with us in recent years have a pretty good idea how we define and approach the idea of custom as it applies to bicycles – at least as far as we discuss it and explicitly demonstrate it. That is to say, we attempt to relay all the potential available to you, depending on your interests, while also trying not to bore all the excitement of buying a new bicycle right out of the process. Now we have come up with another idea, an event we wish to invite everyone to.
The Idea
We spent two days at Seven Cycles’ Factory Immersion event in September. Their tour is truly impressive, but having visited Seven’s facility once before in 2002, this time we were able to really settle in, participate in the presentations, and think about (and discuss) the torrent of information and ideas. This was for two reasons: 1.) Seven set aside two full days of well-designed clinics to actually do this, and 2.) Since we had been impressed by their facility and manufacturing process before, the distracting sense of awe had long since worn off.

Even though, for us, there was relatively little new information, the presentations were fresh, thought provoking, and generated new levels of appreciation for what custom means and how Seven seeks to provide it. We have often found it tricky to present and describe what we do differently, and it became clear during the discussions that Seven is very good at relaying what we all do. We want to think we can be pretty good at it too, but everyone has a different way of explaining the same things, and Seven clearly has put tremendous effort into defining and effectively discussing custom.
Who
We have therefore invited Joe Wignall, from Seven Cycles to come spend a day with us and anyone else who wants to come.

Simultaneously, Joni Taylor from Sinclair Imports, and Paola Del Pesce from Campagnolo Sportswear (yes, the GM from Italy) will be visiting to provide us with a Campagnolo Sportswear Trunk Show. We hope the duo isn’t so dynamic that they distract too much attention from Joe!
For Whom
We have three basic target audiences in mind, in no particular order-of-priority:

1. Cyclists who already own a Seven, and want to know more about why you love it so much or what went into its creation that you may not be aware of.
2. Those who have ever considered a custom bicycle, pondered what the benefits may be for you, and want to know more about what is involved.
3. Skeptics and riders who to want challenge the value, validity, and/or appropriateness of custom as we approach it.
4. Okay, there’s a fourth, but it’s really just to say we hope absolutely anybody who is interested, regardless of whether the first three types apply, stops in to listen, ask questions, learn, and challenge us.

RSVP's are not necessary, but will be much appreciated. Seating is limited (fire codes) and in the event of a full house, priority will be given attendees who notify us before the event.

Rather than post an email link here, please use the contact information found on our website.
How Much
Attendance is free, of course.
And there will be great deals on Campagnolo Sportwear. (clothing, apparel only)
Where
Here at HubBub - 8005 Mayfield Road, in Chesterland, Ohio. We intend to use the Daily Yoga Studio mostly (enter through the High Peaks Coffee shop), as it works very well for presentations and slide shows.
What
Our intention is to provide an inside view of what kinds of expertise, thinking, processes, equipment, and people apply to the creation of a truly fine custom bicycle – specifically in this case through Seven Cycles and HubBub. If you have ever wondered about the fitting processes, capabilities, options, materials, construction, how it’s all achieved, etc. this is a great opportunity to ask the questions and get detailed answers – directly from Seven Cycles.
None of this is carved in stone, but topics considered for discussion include:

• Seven Cycles’ history, philosophy, and future
• What Is Custom? Seven’s 5-Element approach
• Materials – Titanium, Steel, and composites
  Seven’s A6 Carbon platform
  The 5E fork
  Models, tube-sets, and names
• Paint and Finishing
• Fitting, and the Fit Design Process
• Performance, and the Performance Design capabilities
• Our “Tools” and Services
  Test Bikes
  Brochure & Tech Supplements
  Order & Confirmation Process
  Seven’s Manufacturing Card, Flow, Testing, Warranty
  Refinishing
• Aerodynamics, Fit, Power, Efficiency, Speed, Endurance
  What they are, and what they are not – how they are related, and how they affect the design of a custom bicycle.

When
Saturday, February 7th - 11a to 4p
Open at 10:00am and close at 5:00pm.
The actual timing for presentations has not yet been determined, but they will begin at around 11:00am and complete by 4:00pm. We of course do not expect many attendees to want to hang around all day (although anyone is welcome) so we will be using the above topic outline, and the 5-hour window, to develop a rough topic schedule – which we will be providing soon so you can have a general idea of when to come and hear what you are interested in. Presentations should be as flexible as possible however, to maintain interest and answer what we hope to be many questions, so don’t expect a concrete syllabus.

Please attend! and pass this info along to anyone you believe might be interested.

speedster 08

We live for interesting projects. This 2008 three-color fade Co-Motion Speedster tandem I just completed for Rick and Kate is certainly one of them. The captain was nervous about poor shifting, a current epidemic in the tandem community caused by use of modern components made without consideration for the special needs of tandeming.

He requested we use the ShimErgo Solution I developed back in 1999 in attempt to avoid the issues so many new tandem buyers seem to be encountering now. So much has changed in the past ten years but, using a current Shimano XTR derailleur, it's operating just dandy.

Building appropriate drive-trains for tandems, touring, and rando bicycles, using modern equipment, has become more challenging the past few years, with the advent of 10 and now 11-speed systems. It seems too that none of the major component manufacturers are at all interested in supporting equipment that suits the needs of these cyclists. We are continually searching for, or trying to develop, elegant solutions for the folks who are discriminating enough to recognize their wants for something other than what the manufacturers are pushing.

We are also still believers in well designed cantilever brake systems. Check out this beautiful Paul Components Touring brake chosen here. Correctly adjusted they provide plenty of power and excellent modulation. These are very well made, and could not be simpler to adjust, or even repair if necessary.

We take special pride in wrapping handlebars. Except when the hoods are intentionally set at different heights, the two sides should be wrapped symmetrically. This does not just mean directionally, but also there should be the same number of wraps below the hoods, and of course above the hoods. The hoods should extend up to the same distance from the nearest corresponding feathered edge, and the taper beneath the finishing tape should also be symmetrical. One of my favorite "games" to play when the wrap is complete is to check the two remaining tape strips against each other.