Simplex Tour de France Rear Derailleur Adjustment

It’s been quite a few years since I last posted about how to set up a Simplex Tour de France rear derailleur.  These mechanisms were found on bikes dating from the late 1940’s to the early 1960’s, but are not in any way intuitive to fine tune.

The routing of the chain through the pulleys was so puzzling that Simplex had to include a chart in their technical instructions to indicate how this was to be done.  In fact, when I had first started my vintage bike restoration endeavors many years ago I had taken a vintage Peugeot to a reputable bike shop for some repair help with a rear wheel.  When the bike was returned to me, the chain had been incorrectly routed through the Simplex rear derailleur.  That shows just how perplexing this rear derailleur can be.

1953 French mystery mixte with Oscar Egg lugs

Recently, I have been working on my mystery French mixte with its Oscar Egg lugs.  The bike was equipped with tubulars which have proven to be a challenge to keep maintained, as I haven’t ridden this bike on a regular basis, even though they do offer a beautiful and comfortable ride. The glue holding the tires to the rims is no longer robust.  So, upon deciding to temporarily replace the tubular wheelset with a clincher set from the same early 1950’s era, I needed to perform a few tweaks to the Simplex TDF rear derailleur in order to get this bike set up so that I can ride it with more regularity.

My replacement clincher wheels are 700c 1950’s Super Champion rims laced to Normandy hubs.  I wanted to lower the gearing from the the original configuration, but had read that these rear derailleurs can only manage about 24-25 teeth maximum on the freewheel.  I found a 5 speed freewheel with French threads with a largest 25 tooth cog, and then adjusted the internal threaded shaft on the Simplex TDF rear derailleur to tune out the highest fifth gear, as this derailleur can only accommodate 4 gears.  (The bikes’ original drilled Regina freewheel’s largest cog is 21T).  This is accomplished by loosening and removing the nut on top of the knurled washer, and turning the threaded shaft as needed to position it correctly so that the chain lines up with the smallest and largest cogs as the pull chain is moved through its range of motion.  It takes a bit of trial and error.  The knurled nut is meant to be used to turn the shaft, but if that proves difficult, there are flats on the shaft which engage with a 12mm wrench.

Once the alignment to the cogs was correct, I proceeded to adjust the derailleur using the two spring tension adjustments available in this 1950’s rear derailluer:  chain tension, and pulley tension.  The chain tension is controlled by the spring on the arm, and the pulley tension is controlled by the tension on the pulley spring, using the notched mechanism, shown above.  Moving the pulley spring’s position clockwise increases the pulley tension.

Before going further into the weeds, it’s always a good idea to look at a component’s schematics.  Here is the front page of the TDF instruction guide included with these models.  I also consulted the excellent advice from Peter Underwood at the Classic Lightweights website.  After some contemplation, I decided to overhaul a NOS Simplex TDF that I had in inventory, which needed cleaning and re-greasing, hoping this would illuminate this derailleur model’s nuances.

Upon removing the outer nut with a 17mm wrench, I proceeded to removed the pulley cage, which takes an 11m wrench.  The outer steel flexible cover over the shaft reveals an internal spring.  This model had lots of extra washers, which I ended up not replacing (more later!).  After cleaning and lubricating all the parts, came the difficult task of getting the pulley cage back on to the shaft, with its attendant spring.  After some trial and error, I realized there is always a trick to getting derailleur spring back where it should be.

After taking time to review the schematics, I realized that I needed to move the threaded shaft as close as possible to the notched piece, so as to push the moveable part of the shaft down as far as possible.  While holding the spring and cover tightly in place, I was finally able to thread the pulley cage back on, sans a few washers!

And finally, I was successful at re-assembly.  This NOS derailleur now has free-running pulleys with all parts lubricated and is ready to roll.

Meanwhile, I had tried various adjustment scenarios, changing the chain tension and the pulley tension.  The above is a video I made discussing the various adjustments possible for this derailleur.  I initially set the chain tension to push the derailleur back so that I could use the 25T freewheel I had selected.  But, you will see from this video, that by doing so, my shifting performance has suffered.

So I decided to reduce the chain tension by adjusting the nut at the back of the mounting bolt (which has the chain tension spring threaded around it).  This is done by removing the spring from the arm, releasing the bolt, moving the spring back or forward (in this case, forward to reduce tension), and re-tightening the nut.

You can see from the above video that my shifting has improved dramatically.  However, upon taking the bike on a test ride, the torque on the drive train while riding caused the derailleur pulley to contact the 25T cog, making the bike unrideable in that gear.  So, back to the drawing board!  I’ll either switch the freewheel back down to a 24T model, or fiddle with the tension adjustments yet again (NOT!), and most likley swap out the front chain ring for something a bit smaller to help make this bike more rideable for a Portland commute.

For Your Enjoyment

1929 Griffon as restored – out on the Springwater Trail in Portland, Oregon

1929 Peugeot freewheel and fixed cog – for the Griffon’s flip flop hub.

On this Friday evening, with the gentle cool breeze blowing across my summer garden, I thought it would be nice to share some of my favorite photos of my bicycle restorations from the 1920’s through the 1950’s:

1947 Camille Daudon

This custom Daudon was built for Irene Faberge Gunst. The engraved cap can be unscrewed, with a tool kit stored inside the steerer.

A 1946 Peugeot Polymultipliee Gent’s bike

Headlamp by Edelko – 1946 Peugeot

A 1947 Peugeot Mixte. The bike when acquired consisted only of the frame and a few components.

A beautiful Simplex TDF rear derailleur on the 1947 Peugeot Mixte.

Early 50’s Mercier Meca Dural head tube. The upper head badge is missing.

Early 50’s Mercier Meca Dural in a Portland snowy winter. I’ve taken this bike out on the road – very fun to ride. It is built with duralumin tubes which are held together with ornate lugs via internal steel expanders.

A 1953 French mixte with Oscar Egg lugs.

Astoundingly gorgeous Fratelli Brivio (“FB”) hubs were among the many interesting components found on the Oscar Egg mixte.

A 1941 Goeland. My restoration of this bike is still in progress. A rare pre-WWII example.

The Goeland belonged to Annie Laurin – with her address noted on the engraved tag.

1950 Sturmey Archer shifter.

1950 Raleigh Sports Tourist. This bike gets the most views and comments from my readers. It’s an amazing machine, and a joy to ride.

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