Cantilever Conundrum

4 different cantis – vintage to modern- Mafac Criterium; Shimano BR-AT50; Dia Compe 960; Shimano BR-R550

An upcoming bike build will need cantilever brakes.  The frame is new (more on that later), but vintage cantis would not be inappropriate for the project.  As I am not a fan of V-brakes for road bikes, I am exploring the many cantilever options which are available for a frame with canti braze-ons.

Modern cantilever brake options include Paul’s, shown above, as well as other models from Shimano, Dia Compe, Velo-Orange, Avid, and Tektro..  With all these alternatives, it can be hard to determine the best set of cantilevers for a given application.

Shimano BR-R550 with integrated springs

Beautiful Dia Compe 960 Cantis – in as new condition.

But before that a primer on cantilever brakes was in order.  While there are many factors to consider, one of the important ones involves whether you want your springs integrated into the brake or not.  Newer cantilevers, such as the Shimano’s shown in the top photo, have integrated springs that allow for separate spring tension adjustment on each caliper.  Older cantis, such as the Dia Compe’s in the lower photo above have external springs.  The only way to adjust spring tension on older cantis is to mount the spring into a different hole on the canti brake boss (some bosses have 3 separate holes to allow for this).  Or, the spring can be modified with “strong arm” force by changing its shape.

Fortunately, the bike I am working on has 3 hole canti bosses, so I can take the time to evaluate vintage vs. modern caliper options.

1940’s Mafac Cantilever boss

If you have a newer bike and you want to change your cantilever bosses, you can unscrew them from the frame and add a different plate or a different length stud.  Paragon Machine Works is a good resource for sourcing canti studs and plates.

Meanwhile, one has to wonder about the shape and angle of the caliper arms.  It would seem logical to conclude that the arms with the widest angle would have the most mechanical advantage.

But apparently one must think again.  Low profile cantilever brakes can have as much mechanical advantage as calipers with a more extreme angle.  Why?  It all depends on the position of the straddle cable, according to Sheldon Brown.

I experienced this when setting up Tektro canti’s on my 1987 Panasonic commuter bike.  I had to position  the straddle cable very low, but in doing so I found that the brake performed quite well.  The rule of thumb is to not set the yoke below the bottom of the fork crown.  While the angle of the straddle cable looks extreme, the brakes work just fine.

The Mafac cantilevers in my collection are the lightest weight calipers among the group.  Their springs are external of course,  but with the 3 hole option on the frame’s canti bosses, I am leaning toward installing them.  We’ll see!

A Mystery Vintage Touring Bike Courtesy of Fred DeLong

I discovered Fred Delong’s publications much too late in my life.  DeLong’s Guide to Bicycles and Bicycling, first published in 1974 (the year I graduated from high school), is a treasure trove of both technical and non-geeky information, and includes photos and material I have never seen elsewhere.

Fred was a lifelong cyclist, author, and bike guru, and was inducted into the U.S. Bicycling Hall of Fame in 2001, six years after he passed away in 1995.

His book is unusual for its time in American cycle publishing.  It features French, Italian, and British built bicycles, and includes discussions of 650b tires with supple sidewalls mounted on low trail camping bikes, avoidance of toe overlap on touring bikes, and the importance of clearance in frame builds to allow for wider tires, as well as eyelets and baze-ons for fenders and racks.  Sound familiar?

The above photos are close up crops of the original photo shown as figure 2.11 in DeLong’s 1974 guide.  While most of the other photos in the book contain credits or are otherwise referenced, this image was not referenced or credited anywhere in the book.  That means we don’t know who built this bike.

So, let’s start with what we do know about this bike.  According to DeLong, this bike’s features are as follows:

“Wide tubular platform carrier with pannier bags mounted…

Hollow aluminum alloy rims on Phil Wood sealed precision bearing hubs…

Alloy mudguards, front with sliding fender flap in raised position and built-generator lighting…

Mafac Cantilever tandem brakes, rear brake cable direct routing (200 degree cable arc) with hooded levers

Aluminum alloy Randonneur handlebars

531 chrome-molybdenum braze-welded frame – 71 degree head and seat tube angles

15-speed wide-range gearing (23-116) on TA alloy crank and chainwheel set.”

Remember, this book was published in 1974. The photos in the book are all probably from at least one or two years earlier.  Phil Wood founded his hub manufacturing company back in 1971 when, as a racer he became frustrated with hubs developing play and needing an overhaul after each competition. That led him to explore sealed bearing designs for hubs and bottom brackets.  By the time of the 1976 BikeCentennial, Phil Wood’s hubs were all the rave, with touring cyclists ordering up Phil Wood hubs for their wheel builds, in preparation for a cross-country journey.

The above photo depicts an extremely unusual (for the time) sloping top tube.  The builder’s logos are not clear enough to make out, but the down tube seems to indicate “XP SR”.  The seat tube reflects some circular and elliptical logos, presumably also indicating the builder/manufacturer and/or frame tubing transfers.  Is this a custom frame?  I think not.  A custom frame wouldn’t ordinarily have what appear to be model monikers on the down tube. As DeLong indicates in the text, the frame is made of 531 steel and is fillet brazed.  The rear brake features through the frame routing for the “200 degree” cable arc.  While not necessarily a custom feature, it is also certainly unusual for a non-custom frame built in the early 1970’s.

The other intriguing elements of this bike include:

An extension (presumably) on the Mafac levers

A cover (or something similar) on the rear derailleur

A front tire which appears to be wider than the rear tire

A very long reach stem – possibly to accommodate a shorter than desired top tube length

Generous fork rake combined with slack angles

Half step gearing with a tiny third ring

Who made this bike?  Ideas and speculations are welcome.  In the meantime, I discovered a bicycle ridden by DeLong which went up for sale a while back.  The photo below shows the bike, a French JB Louvet built with Reynolds 531 tubing, in disrepair.  But, it may give some clues about DeLong’s interests and preferences.

Fred Delong’s JB Louvet – courtesy of http://bikeville.blogspot.com/

 

Dropping Out

Early 1950’s Simplex dropout – long, horizontal, with eyelet.

Rear dropouts determine what derailleur options are available for a given frame. Rear dropout spacing also determines hub options, with derailleur equipped vintage bicycles having narrower spacing than their modern counterparts.  And, the shape and style of the dropout are important as well:  horizontal dropouts allow for wheel adjustment fore and aft, whereas vertical dropouts make rear wheel removal easier.  Eyelets on the dropouts mean integrated fender and rack mounts, a definite plus.

Little attention is paid to this important feature of any vintage steel bicycle. Vintage dropouts include:  old style Simplex dropouts (shown above – but often model specific), newer style Simplex dropouts,  Huret drop outs (several styles), Campagnolo dropouts, Shimano and Suntour dropouts, and stamped or forged dropouts with no integrated derailleur hanger. Some vintage bicycles feature chainstays with integrated braze-ons or dropouts for Simplex, Cyclo, Huret and other rear derailleurs.

Chainstay braze-on for a Cyclo rear derailleur

1947 Simplex TDF with claw mount

Plain dropouts require a “claw” attachment for the rear derailleur or a braze-on or clamp for the chain stay.  For vintage bicycles, plain dropouts without a hanger do not in any way indicate a lower end frame.  Many nice upper end vintage steel frames did not have manufacturer specific brazed dropouts.  So, do not be afraid of the “claw”.  In fact, having plain dropouts on a vintage bicycle can be helpful, because derailleur options are automatically expanded, depending on the style of claw chosen.

The above Daniel Rebour drawings depict two different styles of Huret dropouts.  Huret rear derailleurs can be a bit (translate “a lot”!) more difficult to set up than Simplex derailleurs. By contrast, setting up Shimano, Suntour or Campagnolo derailleurs with their matching tabbed and threaded dropout at 7 o’clock seems almost too easy.

1972 Mercian Shimano dropout

After the early 1980’s or so, dropout hangers were not so much an issue, because dropouts on derailleur equipped bikes after this point in time featured standard Shimano/Campagnolo hangers which were adopted as the standard by other component manufacturers.

Sheldon Brown’s dropout chart

Sheldon Brown developed this helpful chart shown above, although it is missing some key information.  He does not address the baffling array of hanger styles which existed in days of yore.

A Simplex early style dropout with tab on the non drive side.

Hangerless dropout, requiring a claw

Campagnolo semi-horizontal dropouts on a 1970’s Jack Taylor

Stamped plain dropouts on an early 1970’s Raleigh with a 531 frame

There is only one resource on the web that seems to have a comprehensive overview of dropout styles and rear derailleur compatibility issues.  This helpful chart can be found at a site called The Headbadge.  Velobase also has an extensive database of vintage style dropouts. These resources can help anyone restoring a vintage bicycle determine whether and how to change the existing rear derailleur, and how to determine compatibility options.

In addition, there are a few other web resources that can help you with derailleur and dropout considerations:

An early 1978 article on derailleurs and dropouts by Sheldon Brown, with interesting discussion of Type H and Type S rear derailleurs.

An historic overview of gear selection options through the decades by Bainbridge Classic Cycles, featuring an interesting photo of a freewheel with moveable cogs and a stationary rear derailleur.

The Dancing Chain by Frank Berto is also an important resource – even more so because it is in book form.  If you don’t want to explore vintage derailleurs and dropout styles, the information presented in Chapter 15 – “How Derailleurs Work” will be worth the cost of purchasing this book.  The author’s discussion of derailleur composition, chain gap, pulley spacing, cage geometry, and spring loaded pivots is invaluable to an understanding of how derailleurs work.

1953 Follis with integrated two hole Simplex bracket