1950 Huret Competition Rear Derailleur

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This Huret Competition rear derailleur was equipped on the Mercier Meca Dural bicycle I have been restoring.  When I removed the derailleur from the frame, I wondered whether it was original to the bike.  And, I really didn’t like it – with it’s rigid connecting arm and weird large upper opening which is supposed to connect to the space above the frame’s vertical drop outs.  Perhaps I am a Simplex snob.

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This plunger/pull-chain derailleur is similar to the Simplex TDF and Simplex Juy derailleurs of this era.  But there is an important difference:  there is no upper pivot on the derailleur arm, so it cannot move under chain tension.  During this era, Simplex offered this extra feature on its plunger/pull-chain derailleurs, and I have enjoyed restoring a number of fine Simplex derailleurs from the early 1950’s which work well out on the road.  Instead, this Huret derailleur mounts with a rigid arm extending from the chainstay.  But because this Mercier Meca Dural has vertical dropouts, is the derailleur in the correct position?  The Daniel Rebour drawing shown above shows this derailleur mounted on a frame with semi-horizontal dropouts.  The position of the upper pulley in Rebour’s drawing, allows for more chain wrap, as opposed to my project, with its vertical dropouts pushing the derailleur down, with less engagement of the freewheel cogs.

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Even so, I decided to overhaul the derailleur and keep my misgivings at bay.  The pulleys have ball bearings – a really nice feature – which I overhauled by removing the pulleys from the cage, and cleaning and lubricating them. Each pulley has a set of cones under which the ball bearings reside, which can be tightened or loosened.  I decided to leave the cone adjustment as found, but I did note that one pulley’s cones were quite a bit looser than the other’s.

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I also cleaned and lubricated the pull chain – removing it completely from the derailleur and, cleaning and greasing it,  then re-threading it.  The re-threading is a little challenging – it takes patience to get the threads to re-engage.

One of the challenges with these types of derailleurs is to get the pulley cage in the correct position.  Simplex even offered a drawing in its owner’s manuals to help cyclists install these derailleurs correctly.  Generally speaking, the derailleur should be installed so that the monikers appear upright and/or readable, as shown below:

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I’m not enamored with this derailleur, but after researching its origins, I believe it may be original to the bike.  Even so, I may decide to replace it with a nicer Simplex model from this same era.  First, I’ll test this derailleur to see how it performs.

 

Mercier Meca Dural Restoration Progress

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Restoring vintage bicycles, especially those from the “golden era” which lasted from the 30’s through the 50’s, sounds vaguely romantic and thrilling.  Which it can be.  But the truth is that it can also be a very solemn and tedious process, full of stops and starts.

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This late forties or early fifties Mercier Mecal Dural is one of those projects that can test your resolve.  The bike, whose frame is made from aluminum “duralumin” tubing, was not 100% original, yet the frame itself was in beautiful condition.  Over the course of its life, someone had tried to mount 700c wheels from the 1970’s on this late 40’s/early 50’s bike designed for 650b rims, and had spray-painted over the rust and corrosion on the bike’s original steel fork.  Some parts were missing, such as the original chain guard as well as the bike’s bolt-on attachments for the shifter and chain guard.  And, the Meca Dural head badge was gone.

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Undeterred, I set out to research the history of this method of frame building, as well as to find as many other examples of these frames as possible.  Fortunately, I was successful on both counts.  Several others before me have successfully restored these bicycles, and there is a decent amount of information available on the web and in print which gives a history and background for this interesting frame construction.  However, I still haven’t been able to locate any information on the serial number scheme used by Mercier.  This frame’s SN is 16822.

1953 Mavic rim 650b

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My first task was to find a 650b wheelset from the same era.  I harvested the wheelset from another project, which dates to 1953 and features Mavic aluminum rims laced to Fratelli Brivio hubs.  One of the initial challenges involved rebuilding and restoring the wheelset itself.  While the front hub was easily brought back to its free-spinning glory, the rear hub proved difficult.  I was not able to remove the unbranded 4 speed freewheel from the hub, lacking the particular removal tool.  I modified a Suntour two prong remover, applied copious and various kinds of lubricants to the threads, used both my vise and my giant-sized long-armed wrench, to no avail.  I didn’t want to take this freewheel apart – it is working fine and will probably last another 60 years.  So, that meant cleaning and rebuilding the hub with the freewheel attached.  All went well until I discovered that the original axle was slightly bent. When I was ready for the hub’s final adjustment, I found that the axle could not turn in the hub, due to the zero distance between the hub shell and the cone.  This particular hub has no dust cover, so I couldn’t strong-arm the opening by widening the dustcaps themselves.  That meant trying to find another perfectly straight 9.5mm axle of a similar length and with similar threads.  Amazingly I had ONE such axle in my parts bin – it was only slightly shorter than the original axle.  Whew!  On to the next problem.

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CLB 700 brakes with 650b rims

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CLB 700 brakes with 700c rims

Once I had the wheels rebuilt it became clear that the CLB 700 sidepull calipers were probably not original to the bike.  Their 70cm reach is not quite long enough to engage the 650b rims.  Darn it!  The extra reach needed is only about 2mm.  When there is enough material on the brake calipers to allow for it, you can take a round file and sand the opening lower at the bottom of the caliper arm to allow for a slight improvement in brake reach.  But, these calipers do not have enough material on the lower brake arms to make me comfortable with this approach.  Instead, I will now locate long reach side pulls from this era.  One more setback.

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Tight clearance – chain ring and chain stays

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Stronglight 49D crankset with Louis Verot chainring

Then it came time to rebuild the bottom bracket and install the beautiful, lightweight Stronglight 49D crankset, with its 46T Louis Verot chainring.  Everything went well until I observed the clearance of the chainring to the frame.  I had previously noted what I thought was a crimping mark on the sleeves which serve as the chainstay fender bridge.  When I looked closer, I realized that the “crimping mark” was actually a gouge caused by the chainring contacting the frame at the chainstays, probably under vigorous pedaling.  Investigating further, I found that the chainring itself had a wobble, which is not unusual for this type of crankset with a tiny bolt circle diameter.  A larger diameter can resist stresses from the rider, but the downside is that a larger diameter BCD cannot accept tiny chainrings needed for climbing.

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One of the things I learned in my research about these duralumin frames is that the bottom bracket shell is set up to provide for chain line adjustment.  The shell is a simple aluminum cylinder, held in place with bolts.  In order to address the issue of the crankset contacting the chainstay sleeve under vigorous pedaling, I first measured the torque setting on the bottom bracket bolts, referencing the highest setting at 100 inch pounds as being the most accurate.  After removing the bolts, I twisted the BB shell using the locking on the non drive side of the bottom bracket.  I adjusted the BB shell over about 2mm to provide for additional necessary clearance for the crankset, by taking a mallet and gently tapping the BB.  I would not have known about this option had I not seen numerous examples of other duralumin framesets showing the BB shell in various positions.  Unfortunately one problem with these frames is that the aluminum chain stay sleeves can fail.  I wanted to give this frame a good shot a lasting through the decades, so by adjusting the BB shell, further damage to the chainstay sleeves will be avoided.

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Huret derailleur

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Beautiful Dural Azur stem with arrow design

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Hammered rear light

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Lefol hammered fenders

The next steps involve installing the Huret derailluer and shifter, polishing and cleaning the beautiful components, and setting up the brakeset and cables, and installing the tires, as well as cleaning and lubricating the leather saddle.  Stay tuned for more torture, and related thrills!

A 1940’s/50’s Mercier Meca Dural

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This French Mercier bicycle has captured my attention.  It is made from duralumin – the same stuff blimps were made with – by Meca Dural using a unique procedure to join the tubes with aluminum lugs and wedged steel internal expanders.  The Meca Dural company produced aluminum frames from the 1930’s through the 1950’s on behalf of a number of cycling manufacturers, Mercier being one of them.  A Mercier Meca Dural is included in the Embacher collection (which was sold in its entirety at auction, earlier this year).  The blackbirdsf site also has photos of a variety of duralumin frames of various manufacturers, including Aviac and Barra, as well as Meca Dural.

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This Mercier Meca Dural is a “ladies” bike with a step through frame, although it is not a mixte frame as it lacks the set of extra chain stays typically used to stiffen the frame.  Depending on many factors, this may or may not be a good thing.

The bike features a Stronglight crankset with 46 teeth, CLB 700 brakes with useful and ingenious quick release mechanism, Atom hubs, Samir Saminox 700c rims, Huret plunger/pushrod derailleur, a 4 speed freewheel, and a serial number on the left side rear drop out – 16822.  Here are some photos of the components:

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Huret derailleur with plunger/pull chain mechanism – for 4 speed freewheel.

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Stronglight 49D crankset

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Tank pedals

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Atom hub with Huret wingnuts

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Very nice CLB 700 brakes

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Mercier headbadge, with upper round Meca Dural headbadge missing

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Crankset lettering – Louis Verot chainring with 46 teeth, bottom bracket connector bolt

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Rear drop out with SN 16822

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Beautiful lug design which includes cable routing braze-ons

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Ideale Leather Saddle, Model 80

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Alloy porteur bars, CLB Guidonnet levers, Sufficit grips, Luxor headlamp, Dural Azur stem

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Luxor 65 headlamp

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Samir Saminox 700c steel rims

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Bottom bracket lug, joined below with bolts

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Hammered Le Martele Lefol fenders, hammered rear lamp.

Mercier fork

Steel fork with lugged chrome fork crown, amateur paint job, Stronglight headset

The bike has a number of issues which will affect the restoration process.  The steel fork was horrifically spray painted gray  – so the paint will need to be removed.  Upon closer examination, I have concluded that the wheels are not original to the frame.  There is a 1975 date code on the Atom hub, and not only that, their diameter suggests that this bike was built for 650b wheels and not 700c – the fork crown and rear brake bridge daruma bolts foul the 700c tires.  Clearly the bike was built for 650b wheels, which I confirmed after measuring the CLB 700 brake reach.  And, some features are missing –  the fenders show that the bike originally had a rear and front rack, and the fork mount dynamo is absent, as well as the original chain guard.

Even so, I am looking forward to restoring this machine and to its first test ride, as I want to experience the feel of the aluminum frame and steel lugs, and to judge the frame stiffness for myself.  Stay tuned!