Re: [CR] Simplex CX630 Rear derailleur

Example: Racing

Date: Tue, 12 May 2009 08:43:06 -0700
From: Jerome & Elizabeth Moos <>
To: <>, <>, <>
In-Reply-To: <>
Subject: Re: [CR] Simplex CX630 Rear derailleur

Note the mix of alloy, steel and plastic on the mid and low priced models. And even the top range has one RD that is part plastic. So even at this late date Simplex had not entirely given up their fascination with plastic. I think it was their long-time attachement to Delrin that in large part led to their undoing.

When they first introduced their Delrin derailleurs about 1960, plastics were still considered advanced "space age" materials. But by the mid 70's they had begun to be associated with cheap goods, so what may have made Simplex look advanced a decade and a half earlier caused their goods to seem "cheap" during the Bike Boom. They also used plastic in some inappropriate places, notably the horrible plastic Prestige DT shift levers for which most of the force applied went to flex the levers. Another poor decision was the use of a cheap and thin stamped steel jockey cage on the lower priced Prestige RD, which combined with the plastic shift levers made for very sloppy shifting. This combination appeared on large numbers of Peugeot UO-8s and similar models from other French manufacturers sold un the US during the Bike Boom. I had such a UO-8, and within a year I replaced the derailleur with Shimano Titlist. Probably tens of thousands of Simplex derailleurs were replaced with Shimano and SunTour by American buyers in the 70's

Unfortunately the poor performance of the Prestige tarnished the reputation of the entire line. The top of the line Criterium RD in the early 70's, with a proper forged jockey cage and paired with proper forged alloy Criterium shift levers, shifted far better than a Campy NR. But it had a plastic body like Prestige and looked the same to American buyers, many only just learning about quality lightweight bikes and components. And the fact that both Prestige and Criterium RDs at the time were marked "Prestige" further confused the issue.

So much so, that when I bought my LeJeune F-70 (PX-10 equivalent) new in about 1973, I had the shop change out the plastic Simplex Criterium for the then new alloy SLJ, based on my bad experience with the plastic Prestige. Probably would have changed to a Shimano or Suntour except for the issue with the Simplex DOs. Quite a few PX-10s also wound up with Campy NRs even though one had to go to the trouble of tapping and notching the Simplex DO to fit the Campy. Only after I joined the CR list decades later did I learn that that origianl plastic Criterium I had changed out would have shifted as well as the more expensive SLJ and much better than the Campy NR that some guys went to so much trouble to fit to French racig bikes.

I think my experience was pretty typical of the reaction of the US market to Simplex In The Day, partly based on our own ignorance of European equipment, but also influnenced by some poor decisions by Simplex, but technical and in marketing. I was going to say Simplex had learned their lesson with the later models in the catalog posted today, as the RDs all seem to have proper cages and the derailleurs use plastic to save weight on bits not subject to a lot of flex. But unfortunately, the low and mid priced groups still include plastic shift levers. Most look a bit stiffer than the early 70's Prestige shifters, but shifters are just not a sensible application for plastic.

Most of this later Simplex gear and a lot of the earlier stuff, was very good, and indeed it was Coppi's TdF victory using Simpex derailleurs that finally shocked Campy into introducing a cable operated parallelogram RD. But Simplex made some major missteps in the market that opened the door for SunTour and especially Shimano and eventually led to the decimation, though not quite total destruction of the French bicycle component industry.


Jerry Moos
Big Spring, Texas, USA

--- On Tue, 5/12/09, wrote:

> From: <>

\r?\n> Subject: Re: [CR] Simplex CX630 Rear derailleur

\r?\n> To:,

\r?\n> Date: Tuesday, May 12, 2009, 4:01 AM

\r?\n> Greetings Jon & all,


\r?\n> Not familiar with a CX 630, might we be considering an SX

\r?\n> 630?

\r?\n> Here is a circa 1983 or 1984 Simplex Catalogue which I

\r?\n> had scanned and uploaded in its entirety.


\r?\n> One SX 630 model shown on page 8 and another variant

\r?\n> with a longer cage on page 12.




\r?\n> A useful source of info on later era Simplex derailleurs,

\r?\n> these pages give details of the recommended cog and

\r?\n> chainring sizes and the total chain wrap capacity. Within

\r?\n> the different groups (referred to as bronze, silver, gold -


\r?\n> which were essentially quality & price point

\r?\n> distinctions),

\r?\n> you can better distinguish from the photos the differences

\r?\n> between the sometimes quite similar models, but often

\r?\n> with surprisingly dissimilar gear ranges.


\r?\n> These were the "final" evolutions of many late

\r?\n> Simplex

\r?\n> derailleurs. Many models were definitely little changed

\r?\n> from the late 1970s models. I suspect all worked pretty

\r?\n> nicely... but, by this era Shimano was also producing a

\r?\n> wide selection of derailleurs as well... which were

\r?\n> probably

\r?\n> just as good, or better, and maybe a bit cheaper than the

\r?\n> best of the Simplex derailleurs.


\r?\n> I noticed in an early 1980s Motobecane catalogue that

\r?\n> the Team Champion was using the Super LJ 6600 with a

\r?\n> tri-color "M" logo added right beside the Simplex

\r?\n> script on

\r?\n> the outer parallelogram plate, so they were still highly

\r?\n> regarded... at least for the French domestic market, where

\r?\n> they would also have been competitively priced against

\r?\n> other imported marques.


\r?\n> Many of these derailleurs may still be good values, priced

\r?\n> far below the exalted market prices of the earlier 1970s

\r?\n> models, so these pages may be worth downloading and

\r?\n> saving in your PC files... especially if you are a

\r?\n> Francophile

\r?\n> bargain hunter and could benefit from a "field

\r?\n> guide" to

\r?\n> help distinguish between the ranges and features of all

\r?\n> these models.





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