Category Archives: Meca Dural

1950 Huret Competition Rear Derailleur

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2016-12-16-011

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.

 

Clear Coating a Vintage Steel Fork, Part II

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2016-11-20-015

I have now clear coated the vintage steel fork which was part of the 1940s/50s Mercier Meca Dural I have been working on for the past year.  The bicycle was mostly original, with its beautiful aluminum frame in fantastic condition.  Unfortunately, the fork was terribly pitted, made worse by the application of an amateur spray paint job.

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This Mercier Meca Dural bicycle was built in the late 40’s or early 50’s.  The main tubes are made from “duralumin” – the same stuff blimps were made from. The forks on these bicycles were always steel, and in this case the fork had probably been originally painted gray or was chromed, to match the color of the unpainted aluminum on the main tubes.  Because the main tubes cannot rust, there was no need to paint them.

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But, the original fork was compromised – it was pitted with corrosion and rust. I needed to decide how to restore it or replace it.  After many hours of paint removal, sanding, and polishing, the fork looks much better. I became concerned about removing too much material from the fork blades, so I finally tossed in the towel.   On the bright side (pun intended), I guess you might say this fork has patina in spades.  I ended up deciding that I wanted to clear coat the fork (for now) rather than chroming it or sending it out for a professional paint job.  That would enable me to continue restoring the bicycle, which I am anxious to complete.

I decided to use Proctaclear by Everbrite for the paint, and MAAS metal polish for the final finish work prior to painting.  Both products worked very well.

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The steps I used, after removing the original paint and then sanding with finer and finer sandpaper to create a smooth surface are as follows:

  1. I polished the fork blades and crown with MAAS metal polish – this took hours!  However, I really like this polish and will continue using it for steel parts.  It’s not as good as NevrDull on aluminum fenders, but can make even funky metal parts look very nice.
  2. After polishing, I cleaned the fork blades with alcohol and a soft cloth – I didn’t have to use an acid neutralizing baking soda bath, because as advised by the Protectaclear instructions, MAAS polish does not contain acid.  However, some restorers do this process anyway, regardless of the polish used.
  3. I did a final wipe down on the fork blades with a tack cloth – to remove any debris from the surface.
  4. I cleaned the paint brushes and prepared my work area so that I could avoid fouling the brushes on an unclean surface.  I put the fork upright in my work stand so that the paint would flow downward. My paint brushes were new, so I only needed to wash them in warm water to remove their protective coating – however, see below.
  5. I poured a tiny bit of Proctectaclear into a clean glass jar – this stuff goes a long ways.  The small container I purchased could probably cover 2 bicycles in full.2016-11-15-007
  6. I painted the fork blades with smooth, even strokes.  The paint went on easily, and as the instructions advise, the paint will naturally smooth itself out on the surface so that you won’t see any brush marks.  This was an accurate description, and the painting itself took no time at all.  However…see below!
  7. As I was painting, tiny surface anomalies began to appear in the painted surface.  At first I thought the paint was reacting to something on the fork blades, but then I realized that my paint brush was depositing little particles onto the blades.  The new brushes still had some leftover protective glue which I thought I had washed off.  I then stopped painting, cleaned the brush extensively, then wiped the brush with tack cloth, and that solved the problem. I had to carefully remove the tiny particles with my fingernail (gloved) and then smooth the paint out again.
  8. After a couple of hours, I applied a 2nd coat, as provided for in the instructions.
  9. The paint cures hard in 4 – 5 days.  It is very soft prior to this, and even scuffed a bit when I laid the fork down on a wood surface about 24 hours after the final paint coat.

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The painted fork looks pretty much exactly like the raw steel fork. It really is a clear coat. I will know soon just how robust the paint is, but for now I am excited to begin building up the frame and completing the restoration.

The whole process to restore this fork took well over 25 hours.  Rather than following the typical 80/20 rule for paint jobs (80% preparation time, 20% painting time), this job was more like 99%/1%.  The painting portion of the work was almost a let down, because it was really so easy compared to all the other work involved in preparing the fork.  I’ll plan to do a long-term update once the Mercier Meca Dural is restored and back out on the road.

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Unrestored 1940s/50s Mercier Mecal Dural

 

Stronglight Competition Headset

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2016-08-17 001

While problem solving a fork issue on the 1940’s/50’s Mercier Meca Dural that I have been restoring, I thought about changing its headset so that I could mount a different fork with a slightly shorter steerer tube.

That effort was, sadly, unsuccessful.  But in the process, I had to compare various French headsets that I had on hand to determine which one might solve the problem of needing a slightly shorter stack height.

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1950’s Stronglight Competition Headset

One of the headsets in my bin was a 1950’s Stronglight Competition headset.  The rest of the French headsets I had one hand were 1970’s French headsets – probably all of which were made by Stronglight, but which are unbranded.  When I began comparing this older headset to the (relatively) newer ones, I was amazed at the difference in quality.

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1950’s Stronglight Competition headset cups and cones

The cups and races are beautifully machined, and are of much higher quality than the their 1970’s counterparts, shown below.

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French headset – 1970’s

The photos don’t quite do justice to the quality differential.  But, if you hold these cups and races in your hands and look at them with bare eyes, the difference is clear.  According to this helpful post from Classic Lightweights, the 1950’s Competition headset is made from hardened chrome nickel steel, and feature V shaped races which provide for more bearing contact (thanks to Jim at Bertin Classic Bicycles for clarifying this important distinction).  The newer 1970’s versions are made from lower grade steel, and have U shaped bearing races.

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The nice branding on all of the pieces really motivated me to try to make this headset work on my restoration project.

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Peugeot fork – 1970’s – looks great on the Mercier Meca Dural frame

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Original Mercier steel fork on the right, Peugeot fork on the left

The original fork was seriously compromised with rusting and pitting on the fork blades.  I had sanded off the pitting and have been searching for the right solution which would result in either an original newly chromed fork, or an original newly painted fork.  I was not able to find any painter or chrome-plater in the Portland region that I wanted to trust with this vintage fork.  So, I looked around at the forks I had on hand.  One of them was a 1970’s fork from a silver Peugeot.  The steerer tube was shorter than the original fork by about 5 mm.  Drinking some Kool-Aid, I decided that maybe I could make this work, after all, the fork looked perfect with the Meca Dural aluminum frame, as you can see from the above photo.

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After doing a bit of research, I determined that I could eliminate the lock washer and instead apply some Locktite to the steerer threads.  That would save about 2 or 3 mm.  But, to make this work I needed to Dremel off the pin on the top of the 1970’s headset that I originally envisioned as my solution to the problem.  Okay, that was easy.

Unfortunately, when I dry mounted the fork into the headtube, I forgot about the space that the 5/32 inch bearings would need.  So, I ended up with only 2 or 3 threads showing on the steerer tube above the upper cup, after installing the bearings.  That’s not enough.  You really need at least 5 or 6 threads showing in order to feel confident that the steerer tube will stay in adjustment, especially if you are going to remove the lock washer.

So, it’s back to the drawing board with the fork.  I either need to find an appropriate replacement fork, or the right company to chrome-plate or paint the original fork so that the bike can be restored to its original glory.  But, the 1950’s Stronglight Competition headset gives further evidence to the quality of vintage cycling components as compared to their modern day counterparts.