Book review – Lugged Bicycle Frame Construction

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I have recently been considering getting some brazing equipment so that I could make repairs to frames that have minor failures, rather than sending out to a frame builder for this service.  Having taken UBI’s lugged frame building class a few years back, I had a general idea of what I might need, but didn’t want to go any further until I re-familiarized myself with the topic of brazing.

I found Marc-Andre Chimonas’ book, Lugged Bicycle Frame Construction, on the evil empire (Amazon) website, with what appeared to be some favorable and thoughtful reviews by actual readers.  When the book arrived, I immediately delved into it and have now read if not studied much of the book.

It is written with a dry, understated wit, with an emphasis on the science of frame building.  There are numerous zingers in the text, hidden amongst the tables and formulas.  Consequently, I thoroughly enjoyed reading it.  The author is a physician (which he describes as his “day job”), a writer (of both technical manuals and fiction), and a frame builder.

After reading just the first few chapters, I began to seriously question the idea that anyone can take a frame building class that lasts only two weeks, and from which an actual frame is produced.  Whether that frame is safe to ride may be another thing altogether.  My own frame has several flaws that can probably be corrected, but more on that later.

The book is logically organized and takes the reader through introductory concepts such as nomenclature, frame geometry, measurement and sizing protocols and includes helpful tables for determining angles and lengths for different sized riders.  He naturally recommends smaller wheels for smaller frames, and there is a good discussion of toe overlap and bottom bracket height.  He states his opinions about frame geometry as if they were facts, and that may irritate some readers, but I found it refreshing.  For instance, recommended BB height is 25 cm for pretty much all types of normal road riding.  This is a lot lower than you will find in production bikes.

Another interesting concept that I found both helpful and puzzling was the idea of controlling the variables in frame building.  He differentiates between “operator controlled” variables and “outcome” variables.  Outcome variables are the result of the frame builders operator controlled variables.  But, he describes outcome variables to include BB drop and toe overlap, which in my mind are operator controlled.  At any rate, what is clear is that frame design is a highly complex  undertaking, and one that is aided by software.  He recommends using excel and offers a link to a useful frame design spreadsheet, which is available on the author’s website.

There is a quick trigonometry and metallurgy review (which the author calls optional), and then the theory turns into fabrication as the author goes through chapters on frame parts, tools, mitering, torches, brazing technique, and lug modification.  Again, the author doesn’t hesitate to state his recommendations, even down to a specific brand or manufacturer of a particular tool.  For me, someone who didn’t take shop class in high school, the specific advice is extremely helpful.

After digesting many of the chapters, I decided to drag out the frame I completed 2 years ago but never finished filing or painting.

My frame with front-center at 59 cm - a little shorter than I wanted.

My frame with front-center at 59 cm – a little shorter than I wanted.

I built this frame for myself, designed around a 650b wheel size.  I wanted enough front-center distance to allow for fenders and decent sized tires.  The book uses a formula to determine an ideal length.  I plugged my numbers into his formula and found that I won’t have toe overlap with this frame, so that is a relief.  I did have to use a longer than usual (for me) top tube length to get this much front center distance (combined of course with all the other measurements).  That means I’ll use a short reach stem when I eventually build the bike up.

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One of the things that troubles me about my frame is that it was built so hastily and with so little actual knowledge.  Well, after reading the brazing chapter I think I have reason to be concerned.  I remember having a lot of trouble sanding enough material off the top of my fork blades, and off the inside of the fork crown so that the legs could be inserted without a lot of force.  After hours of filing, I still wasn’t happy, but ran out of time so just brazed the fork legs into the crown even though the fit was tight.  This is definitely a no-n0 – there needs to be enough room for the silver to flow into the joint.

Here are some other details of the frame I built.  Using this book as a resource, I will be able to correct the other two (known) mistakes on the frame.  I may decide, however to build a new fork.  And, I now know what kind of equipment to purchase and how to use it safely, so I am looking forward to being able to do my own small repairs.

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Nice looking BB

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Mistake on the seat stays – they are out of alignment

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Drive size DO not yet cleaned up and filed – you can see I got the tubes a bit hot.

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Aaack! Seriously out of whack shifter bosses – the jig probably got bumped when I turned away to get more silver.

1980 Meral 650b Conversion – Long Term Update

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I’ve been riding my “new” 1980 Meral 650b for over a year now.  Only recently has it become my bike of first choice, however.  As with any bike, and especially with a frame-up build combined with a wheel size conversion (700c to 650b), there were a number of challenges and some disappointments.  Here is an overview of the results:

Frame and Fork:

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My favorite aspect of this bike is its beauty and the build quality of the frame and fork.  It’s just an absolutely gorgeous, well put together bike.  The Reynolds 531 tubing feels great and is not punishing, as can happen with stiff aluminum frames (especially smaller frames).  I love the chrome accents and chrome fork, and the lovely sloping fork crown.

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The deep purple color is eye catching and I like the gold lettering of the Meral logos, which goes with the gold-lined chrome lugs.

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The frame geometry is suited for my riding preferences – with a steep seat tube and head tube angle.  It has more stand over height than I really need, and if the frame were taller I would not have had to use a Nitto Technomic stem to get the bars at the height that feels good (slightly higher than the saddle height.)  But, it wasn’t custom built for me, after all, so I’m not complaining.

Tires, Wheels, and Handling:

Panaracer Col de la Vie 650b tires

The Panaracer Col de la Vie 650b tires were extremely disappointing – to the point that I actually stopped riding this bike while I figured out what to do.  They produced a lot of tire noise, and the deep treads picked up rocks like a vacuum cleaner, then spit them into the aluminum fenders, for an even greater cacophony.  The tires felt squishy and ponderous no matter what pressures I tried, and made climbing feel like I was riding through quicksand.  On descents, the bike was noticeably slower than ALL my other bikes, causing me to conclude that the tires had an enormous amount of rolling resistance.  Since the tires come so highly recommended, I delayed changing them out while I tried out other theories to explain the bike’s slowness.  Were the wheel hubs improperly adjusted?  Was the freehub bad?  No, and no.

Velocity Synergy 650b Velocity Synergy 650b Wheelset

In fact, I am really happy with this Velocity Synergy 650b wheelset.  The hubs were adjusted perfectly right out of the box and are very smooth.  I did have to make a small truing adjustment to the front wheel, and that was all.  I ordered this 32 hole set from Rivendell and I think they were well worth the price (about $400 for the pair).

While I pondered what to do about the tires, I also had to contend with a problem that I had never experienced before to this degree:  fork shimmy!  The bike shimmied from the get-go, at high speeds and slow, and would get worse if I rode with just a single bag in back instead of two.  So, I did a lot of reading about fork shimmy and found that it is as mysterious as “planing”, “q-factor” and bottom bracket drop in terms of facts vs. mythology.  For instance, Jobst Brandt has a pretty scientific explanation of fork shimmy.  Here is a quote from his treatise on the matter:

“Shimmy is not related to frame alignment or loose bearings, as is often claimed. Shimmy results from dynamics of front wheel rotation, mass of the handlebars, elasticity of the frame, and where the rider contacts the bicycle. Both perfectly aligned bicycles and ones with wheels out of plane to one another shimmy nearly equally well. It is as likely with properly adjusted bearings as loose ones. The idea that shimmy is caused by loose head bearings or frame misalignment seems to have established currency by repetition, although there is no evidence to link these defects with shimmy.”

He goes on to state that shimmy is caused by the gyroscopic forces of the front wheel, which combined with the tilt of the steering axis, exerts force on the top tube and downtube, causing them to oscillate.  While absorbing this explanation, I read a number of other explanations, but none seemed as true to my mind as this.  Based on that, I concluded that I definitely needed to replace the Panaracer tires because I felt they were contributing to, if not causing, the shimmy problem, with their deep tread pattern.

Compass 650b tires

I finally broke down and ordered these Compass Loup Loup Pass 650b tires.  I ordered the regular model, not the super-light.  Conclusion:  what took me so long!  These are the best tires I have ever ridden, ever.  They are comfortable, fast, quiet, and seem to help spur me up hills.  I have ridden them on gravel, pavement, and over some bad and deep potholes.  They are fabulous!  Now, when I take the Meral out for a spin I find that I end up riding far longer than planned.  They have restored my enjoyment of riding, and have really been the turning point in making this bike my favorite.  And, I have absolutely no more fork shimmy, at any speed.  So, I guess we can add tire tread depth and design as a possible contributor to fork shimmy – let the mythology continue!

Drivetrain:

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The vintage TA triple crankset had a massive wobble so I had to disassemble it, place each chainring between two planks, and smash the hell out of them in my vise.  It took enormous force to get them straightened, but now they are fine.  The rings are 48/40/28.  For this kind of bike, I really need some smaller rings up front, plus I prefer to have a 10 tooth difference between the big and middle rings.  Rather than replace the TA rings, I decided to change the cassette.  First of all, I had to accept the fact that I could not use an 8 speed cassette on this drive train – the Ultegra front derailleur could not handle it.  Instead, I put in a spacer and ended up with this 14-32 7 speed cassette after trying 3 other cassettes that had higher gearing.  I decided to stick with the Ultegra derailleur, though, because after doing much research I realized that it can be very difficult to find any front derailleur that will work with a TA crankset, due to its narrow tread.  So, if it works, don’t fix it.  The bike is geared a bit lower than my other bikes as it is a bit heavier, and I ended up replacing the SLX rear derailleur with the Deore pictured above which seems to work better with the larger cassette cogs.  I am using my Shimano bar end shifters in friction mode and the shifting is fast and precise, with very little trimming needed.  One of my favorite pieces on the bike is this modified Huret downtube clamp which can accept Shimano shifter pods – it looks great and the pods mounted precisely.

Braking System:

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I used vintage Mafac Raid brakes to accomplish the conversion to 650b.  This set was in nice shape and included all the mounting hardware.  Because I was working with what was originally a sport touring bike, made long after these Mafac’s were manufactured, I had to make some modifications to the hardware to make things work.  For the Mafac rear fender mount, I had to reverse the piece, tap out the other side, and mount it backwards in order to make it work with the brake bridge on this bike.  I also “smooshed” the brake hanger and installed a longer seat post bolt to get the hanger to work with this bike.  The brake arms are very long, as you can see, and naturally have a lot more flex due to the long reach.  My Kool Stop replacement pads squealed like crazy for the first month or so of riding, and then finally everything settled down and braking is silent.  However, the front brakes have a squishy feel, which is consistent with my experience with Mafac’s on other bikes I have ridden and restored.  But, they get the job done, and that’s what matters.  I am using Shimano aero levers, which fit comfortably in my hands – I use these for all my bikes with road bars.

Saddle, Rack, Bags, and Fenders:

Cardiff Leather Saddle

The Cardiff saddle, a brand I haven’t tried before, turned out to be a real hit.  It is breaking in nicely.  It has longer seat rails than a Brooks, and a slightly different shape that seems to work well for me.  The saddle is big enough to provide a number of different seating positions depending on where my hands are on the bars.  In short, I will probably not go back to riding Brooks saddles as I find the Cardiff far more comfortable (comfort being a relative term when speaking of bike saddles…).  And, it’s a pretty handsome saddle that goes perfectly with my plum-colored leather mud flap.

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For my rear rack, I had wanted to use the Velo-Orange constructeur rack.  It is very pretty and mounts to the rear fenders, which makes the rack sit down nice and low – ideal for carrying weight in the back.  At the time I was building up the bike, that rack was out of stock, so I decided to try out the Electra Ticino rear rack instead.  While the rack itself is not ugly, per se, it sits up very high, has unadjustable stays, and is very heavy. I sanded the stays to allow for greater adjustment so that I could level the rack (photo above is before I had done this), so that helped a bit.  The Ticino panniers are nice bags, but are also very heavy and suffer from being oddly shaped.  Nonetheless I have continued to use them and they have held up well.

Meral 650b conversion

Here is the bike now, after all these mods, and after a year of riding.  It’s a very striking bike, and now a very comfortable bike after tweaking the components and upgrading the tires.  Today, I meant to go out on just a short ride, but ended up two towns away!  This bike has finally exceeded my expectations.

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1980 Meral at Smith & Bybee Lakes

The Bond Between Bike and Rider

1976 Centurion Pro Tour

Being a pragmatic person at heart, I generally eschew mystical explanations of purely mechanical matters. However, there’s no doubt that a special relationship between bike and rider exists when the bike in question has carried the rider over many miles and through rough terrain, dangerous intersections, and bad weather.  Much like a shepherd and beloved dog will form a bond through shared hardship, a rider and bike seem to connect in an almost spiritual way.

I experienced this myself with my old 1976 Centurion Pro Tour that I rode for 20 years. The bike got me through some tough situations, and always carried me to my final destination. Even with flat tires, broken shifters, and a headset long overdue for a replacement, the bike soldiered on and I always arrived safely at my destination.

After I crashed my Pro Tour in 1999 I was at loose ends. I searched for a replacement and ended up buying a Cannondale T 2000. What a shocking disappointment that was.  The brifters broke when the bike took a spill while parked, the Avid Shorty brakes were frighteningly unreliable, and the stiff aluminum frame was punishing on long rides.   Not to mention its piggy 28 lb weight unequipped.  I no longer enjoyed exploring new dirt paths, back road short cuts, and long meandering rides.  I wanted to get off this bike as soon as possible.

The search for the ride quality that my old Centurion provided was a long one.  Meanwhile, I modified the Cannondale substantially, replacing the brifters with bar end shifters, upgrading the brakes to IRD cold forged cantilevers, installing an SR Randonneur bar, and adding a custom Burley rear rack originally designed for a recumbent.

2001 Cannodale T2000

After these modifications, I was able to ride the Cannondale in a little more comfort.  Replacing the harsh riding Continental touring tires with Panaracer Paselas helped.  I also tried out some Michelin cyclocross tires, which were also quite a bit more comfortable than the Continentals, and enabled me to ride with confidence on gravel shoulders and hard packed dirt and gravel.  Eventually, I ended up replacing every single original component on the bike except for the reliable Shimano 105 front derailleur.  After that, this bike became my trusted commuter, especially in the winter.

But, I wanted a bike that I could comfortably spend more hours on and was more responsive.  I missed my Centurion tremendously so when I found this Centurion Dave Scott Iron Man in my size, for a reasonable price, I purchased it without hesitation.

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This was a road bike, not a touring bike, at all.  Riding it was eye-opening.  I could ride for miles and miles, never tire out, and the responsive handling made it fun to experiment without fast descents, track stands, quick transitions, and spirited climbing. After a while, though, I realized that without clearance for fenders, rack mounts and a taller stem, I would not be able to take this bike out on the touring adventures that I love.  I realized that I needed the comfort and responsiveness of riding on steel framed bikes, and that I wanted to learn more about the physical and mechanical details of bicycles and their geometry.

That’s when I enrolled in my first bike mechanic class at the UBI facility in Ashland.  Even though I had always done my own bike maintenance, back then I had not really spent any time understanding much beyond annual maintenance needs, which included rebuilding hubs and bottom brackets,  truing wheels, and tuning shifters and derailleurs.

I had a great time in the class and met a lot of interesting people.  The class opened my eyes to the world of mechanical possibilities and experimentation – I highly recommend UBI for mechanic’s training.  Prior to attending the class I had already acquired a 1973 Jack Taylor touring bike and I brought it with me to work on while I was there.

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1973 Jack Taylor Touring – before restoration

While this bike is a wonderful example of the Taylor brother’s work, after riding it for a bit I came to realize that it wasn’t quite right for me.  I did not like the unstable feel of the single sloping downtube mixte frame – I could feel the front end flexing away from the back end of the bike while accelerating. I also did not like the ergonomics of the low head tube and short reach mustache bars.

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I have realized that ergonomics are as important as frame material and components.  And, I  know from personal experience that steel is flexible and responsive on climbs and does not punish your body on long rides, as does aluminum. This is especially important for smaller riders whose frames are much more stiff than those for taller riders, due to their geometry.

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It is clear that newer components are designed deliberately to last briefly and to be discarded when they no longer function.  This has led me to go back to cycling’s past to understand and rejuvenate the contribution made by earlier builders and artisans.