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.

Goodbye, Old Friend

I’ve bought and sold a lot of bikes and frames over the years.  Some were bikes that I meant to restore/refurbish and pass on, others were bikes that I rode for a while and decided against keeping them as daily riders. Letting a bike go doesn’t really mean much about the bike itself, but does mean something about the rider.  Each of us has unique interests, passions, body geometry, needs, desires, and energy, and some of these might change over time.  The right bike will be transformative.  Knowing when to let go of a bike is an elusive skill set.  Here are a few bikes I’ve passed on for others to enjoy:

A 1960’s Raleigh Royale, converted to 2 speed:  This bike was one of my forays into single speed riding.  I kept the close ratio double front crank, and used a single speed freewheel at the rear, with no front derailleur.  Riding this bike helped me realize how much I didn’t want to ride single speed or fixed.  The idea was that I would move the chain by hand on the front (a la the old days before front derailleurs) and then move the hub in the dropouts to adjust chain tension.  In practice, I never did this.

A Bridgestone X0-5:  this bike came to me with all original but low-end components.  I removed those and replaced them with some much nicer parts., including a SunTour Sprint crankset.  The very nice Cro-Mo frame on these bikes is the same as the higher end versions, and so with a bit of upgrading this was a wonderful bike to ride.  I kind of regret selling it now, but on several occasions I’ve spotted this bike out in Portland’s wild, ridden by its very happy new owner.

A Reynolds 531 Cilo Pacer:  this was my first foray into Swiss bikes.  Cilo went bankrupt in 2002, but prior to that was known for building some very nice machines.  The frame had some minor rust, and the components were racing oriented.  I decided to pass the bike on without building it up, as I wasn’t sure it would be right for me.  It was equipped with a full Campy groupset, which I saved, and ended up selling the frame to a very interested younger cyclist.

A 1979 Large Peugeot Mixte:  this basic Carbolite 103 Mixte was actually really fun to ride.  Everything on this bike worked well, with very little restoration needed.  It’s an extra large mixte – perfect for taller commuting cyclists, and features a front bottle dynamo, working perfectly.  I hope whoever has this bike is enjoying it.

A Schwinn Passage touring bike:  this is the bike that “got away”, and I now wish I still had this one in my stable.  It’s an amazingly competent and practical touring bike that works equally well for commuting and sport riding.

An Early 1980’s Davidson:  I wanted to love this bike, but never was able to come to terms with its geometry.  I put a lot of miles on the bike before selling the frame and fork to a cyclist planning a touring adventure.  I kept the original Shimano 600 components, transferring many of them to my early 1990’s Terry Symmetry.

If a bike doesn’t feel right for you, even after making a few modifications, then it’s time to pass it on to another rider.  A bike that gets ridden adds so much value to the whole scheme of life.  Bikes are highly personal, very unlike cars.  The comfort of the cyclist is paramount, so don’t feel bad about selling a bike on.  Its new owner may find a lifelong friend.

Reinterpreting a 1978 Peugeot PR65

I’ve had a  blue 1978 Peugeot PR65 in my shop for some time.  The bike was 100% original when I acquired it, and is in beautiful condition.  I had put it together after its arrival from France, but was unhappy with the ergonomics and with some of the components.

There were two versions of the PR65 in 1978, but only one appears to have been built with the Reynolds 531 tubing used on this bike – the “luxe” model.

The paint quality is very nice, and the bike looks nearly new.  All of the nicer components of this era are present – a Stronglight TS 3 arm crankset with 48/38 rings, Mafac Racers, Mavic rims and Bluemels fenders to name a few.

Plastic Simplex components removed.

Simplex shifters removed.

But the incredibly uncomfortable ergonomics (long top tube combined with low stem and no rise porteur bars) along with the ugly plastic-infused Simplex components made me want to make some changes, which is not something I will usually do with a 100% original bike.  But, a bike that gets ridden is always a better bike than one that is not.

A good example of the hideousness of Simplex’ obsession with plastic during this era is shown above.  A normally elegant downtube cable guide is made into a bizarre monstrosity.  Often these plastic components will break, especially the plastic clamp for the front derailleur, so I also regard these plastic Simplex components as unreliable.

Simplex dropout as modified to accept both Shimano style and Huret derailleurs.

Notch engagement on the Huret derailleur.

B screw engagement for a Shimano style derailleur.

First up was the need to do something about the Simplex dropouts, since I wanted to have other rear derailleur options.  I decided to attempt to file notches in the the plain round unthreaded dropout, and to tap it out to 10M.  I created both a “7 o’clock” notch for Shimano style derailleurs, as well as a set of notches for Huret.  The process took quite a while, but I was successful.

Wanting to be true to the bike’s French heritage, I chose to use replace the Simplex components with Huret, selecting a Svelto for the rear derailleur.  The Huret front derailleur is a bottom pull style that needs housing, so an appropriate Huret cable guide with a housing stop is also needed, as shown above.

Replacing the bars was also not a simple swap, due to the French sized steerer tube.  Since I wanted to use a modern upright handlebar, I needed to sand an appropriate stem down to French size (22.2 to 22.0), which also takes a bit of time and patience.  This is a vintage Cinelli stem mated to a set of Nitto tourist bars.  I needed some strong and reliable shifters to handle the Svelto rear derailleur, and these lovely vintage Suntour bar mounts do a great job.

The bike as now configured is amazingly comfortable – perfect for commuting and for exploring.  If I were to keep this bike, I would probably cold set the rear triangle to 126mm (from 120mm), and build a set of 650b wheels around a nice, vintage hubset.  This would allow use of wider tires than the 700c x 28mm tires shown above, which is about as wide as the bike will accept with the Bluemels fenders.  I’m planning to list this bike soon on my store page, so I’m hoping it will find a new home and have a chance to get back out on the road, as the bike certainly has many miles to go, and will get you there in true French style.