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Classic Lightweights UK
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Simplex Retrofriction levers

Peter Underwood
 
Simplex Retrofriction components 1The Simplex Retrofriction down tube levers were introduced in 1973 and they soon became a favourite amongst road racers who, John Spooner tells me, replaced the somewhat temperamental Campagnolo levers with these more refined and easy to use models. The levers have a balancing spring to reduce the likelihood of the lever slipping and as a result can be set up with less tension which makes them smoother in operation.

Under extreme racing conditions the Campag levers had to adjusted very tightly to avoid them slipping from bottom gear at a critical point on a hill climb.  This made them quite hard to use accurately for other changes.

Right: Simplex Retrofriction levers on band

These levers come up for sale from time to time but usually they are in braze-on format, i.e. no band-on included. Simplex bands can be found but strangely the bolts will not screw into the bands as there is a difference in thread, one assumes there are different threads for different levers within the Simplex range.  The bolts are very close to 5mm but not  quite the same. You may find that the bolts supplied with the levers don't fit and neither do the 5mm so there must be another, very similar, thread  used. I have run a 5mm tap through and used 5mm stainless bolts on the levers shown so hope this will do the trick.  

The Dancing Chain states that Simplex also produced a bar-end version of the Retrofriction levers but I don't have any of these as yet.

Later versions of these levers had AK securing bolts in place of the earlier slotted ones shown here.

Mike Baker adds: I agree with your comments about Campagnolo down tube levers, they were the Achilles heel of the system. I once saw Sid Barrass lose a race on a steep hill when his gear lever slipped. He shouted out for a screwdriver, and the bunch heard him and rode away! I used the centre bolts with the little D rings on them and a shakeproof washer behind them, but they still slipped.

I have a pair of retrofriction levers, braze on, which are quite the nicest I have ever used. Robert Miller used a pair in the Tour de France with Campag gears.

My theory is that the braze on type were imported to fit Campag brazed-on lever bosses which were almost universal in the UK, hence the centrebolts will not fit Simplex lever bands. I actually preferred band on levers as they were more robust and the thread wore very quickly on the Campag brazed-on bosses. Presumably the Simplex band-on had the standard Simplex threading. I know Simplex produced standard handlebar end controls in the 1960s but I have never heard of a retrofriction model.

Incidentally, I have used Campag bar-end controls for 50 years without realising they had an allen key tightener. We always used to tighten them by screwing them in with the leverage of  the gear lever. How stupid can you get?  The only drawback to applying leverage clockwise to the campag thumb lever to tighten the internal spring was that it was not very tight and could loosen,sometimes when riding! Your system seems a lot more stable. The other thing I never mastered was threading the internal gear wire around the handlebar control without kinking it and also getting the tiny nipple in the hole.

I did read an article once, possibly in Sporting Cyclist where a Belgian pro team mechanic advised against handlebar controls, saying they were unreliable in the rain, but I could not understand this as they were universally used by top pros like Rik van Looy and Tom Simpson.

Martin Vincent
tells us: You sometimes come across these levers without the 'Simplex' lettering. I believe that these were made by Simplex for Mavic and sold as part of the Mavic groupset. I have used Simplex retrofriction levers with Campag braze-ons without a problem but I think there may have been two alternative types of screw thread available. French frames usually had some weird French bicycle thread so Simplex would have had one type for that and another for compatability with Campag. Of course you can always swop the original Simplex fastening screws for allen-head bolts if compatability is an issue.

Simplex Retrofriction components 2


Below is an image showing the component parts of the Retrofriction levers.  Sadly it doesn't indicate how the spring is located in the body.
The small piece shown at the left of the top lever, and the right of the bottom, is the boss for brazing to the frame.
Band-on is shown in three different sizes to match tube diameters.

Simplex Retrofriction 3
Thanks to John Spooner for this image, he also has an illustration of the Mavic version

Charles Colerich from Oakland, USA was inspired to run a check on his Retrofriction levers:

I've messed around with Simplex Retrofriction Levers since about 1975. I remembered that there were at least 2 different screw threads used by Simplex to mount their levers back then. For some reason I was thinking they were the industry standard M5x.8 plus M5x.7 or M5x.75 but that may have been Huret levers.

It's been almost 35 years so the other night I checked out the threads on about a dozen Simplex levers that I have:

ALL of the Retrofriction levers that I have or that I've seen use M5x.8 screws. This includes the clamp mounted ones too.

I checked some old Simplex clamp on levers with the plastic wing nuts used to tighten the hex head screws. Both the plastic Prestige levers and the metal Criterium levers that I checked all had M5x1.0 threads.

I have several pairs of what I suspect are Italian made clamp-on Simplex metal levers. the levers themselves are aluminum with plastic caps. The rest of the metal parts are zinc or cadmium plated rather than chrome and they have slotted button head screws instead of wing nuts. They both had M5x.8 screws.

I have several NOS Simplex clamps. One is the old early 70s style with a round raised "S" in the middle of the narrow band. The other has a wide band with an "S" in the "sun" logo. Retrofriction levers fit on both of them but the old one takes M5x.8 screws while the newer one M5x1.0 screws.

So what does this mean?

Simplex Retrofriction levers "should" fit on any Campy style braze on lever boss with a M5x.8 screw thread.
Note, some of these levers have longer M5x.8 screws than others. The boss may need to be (gently) chased out with a tap first or else the screws may need to be shortened.

Many Simplex Retrofriction levers just have a nylon washer holding the screw into the body. If I remember correctly, some of the early ones used metal snap rings to retain the screws. They were hard to remove.

The early levers had the chrome plated, slotted button head screws. The slots stripped pretty easily. Once that you removed the original screws you could replace them with any M5x.8 screws with the correct thread length (including Campy "D" ring screws).

If you are looking to convert some Retrofriction levers to clamp on, make sure that you find a clamp that takes M5x.8 screws.

Everything stated above is subject to the whims of Lucien Juy's unpredictable reasoning!