Nervex Professional Lugs

Author: Martin Vincent (with some input from Peter Underwood) plus additional pieces by Peter Brueggeman and Norris Lockley

Until the advent of the Nervex Professional lugs many framebuilders cut their own trademark lugs in-house.  This was obviously very time-consuming and relatively expensive.   Before the Professional many companies, including Nervex, produced pressed steel lugs of various designs which were used some as produced and some modified.

The Professional though was a classic design destined to succeed from the day it was introduced.  The lug just looked right, beautifully cut with pleasing lines and not needing to be over-elaborate as some lugs could be. Also, these pressed-steel lugs were relatively light and well finished, apparentlyneeding less filing and cleaning-up than some of the cast steel designs available at the time.

Frame builders took to it at once and more importantly, so did the public. Part of its success can be attributed to Nervex lugs being chosen by many of the top frame builders and racers on the continent; Louison Bobet reportedly won the 1950 French Road National Championship on a Stella frame built with a Nervex Pro lugset. Naturally, the Brits wanted the same equipment on their machines.

The Nervex Professional lugset is now considered a classic design yet it was remarkably prolific. Throughout the 1950s and 1960s almost every frame maker used Nervex Pro lugs at some time or other and this was equally true of exclusive  frame makers  (Gillott, Bates, Ephgrave, Jack Taylor, De Rosa, Colnago, Bianchi, Masi - and many others) to the mid sized (Viking, Dawes, Holdsworth, Carlton, Mercian) and even the largest mass producers (Raleigh, Peugeot, and Schwinn and Paramount in the USA).  It might be imagined that the mass-production of these lugs might diminish their significance as a classic item. This has clearly not been the case.


Nervex Professional seen here (and above right) on 1955 Gillott - this has the later version of the lugs and the centre/front of heads have been filed to give a finer profile to the 'fishtail'


The Different Types

The first Nervex Pro lugs were produced with a vary fine pair of ‘horns’ at the centre-front of the two head lugs. Later on the lugs were changed slightly and the ‘horns’ (left) were replaced by a ‘fishtail’ (right). This newer design was certainly in use by 1955 although the earlier style was still used by some frame makers for some time after, presumably because lugs were often bought in boxes of 50 or more, and these would take time to be used up.
Nervex developed and produced their range of lugs in the post- WWII years, late 40s, but the first time they were imported to the UK seems to be around 1950.
As well as the early and later type lugs, there were also differences in the detailing. Almost all lightweight frame builders would lighten and clean up the lugs to some extent, usually filing them to feather the edges, but often the edges themselves were filed to produce a crisper and better defined shape. Comparing similar Nervex Pro lugs on a 1962 Viking,  a 1986 Mercian and 1955 Gillott machines, it is clear that the Gillott has better detailing. This is most apparent in the shape of the 'fishtail' on the Gillott head lugs. The 'V' in the centre of the fishtail is deeper and has better definition. On the other hand, it is quite possible that  the standard of finish of Nervex pressings may have diminished over the years, thereby offering a different explanation a to the higher quality of the Gillott.

1955 Gillott

1962 Viking

1986 Mercian

Other changes amongst different frame makers centre on modifications to the lugs themselves. Clearly, the more highly-regarded frame makers would not want their own products to be the same as anyone elses. In order to achieve this they would often modify Nervex Pro lugs either by cutting away parts or making 'windows' in the lugs (such as the Ephgrave No 2 lugs), or by adding spearpoints or other shapes (Holdsworth used this technique on certain models).

The Nervex Professional was produced with a strenghtening rib at the top and bottom edge of the headlugs.  This rim can be seen on the lugs to the right (Bates).
Several framebuilders considered this an unnecessary feature and felt that it detracted from the simplicity of the lug.   When a frame is well built the top and bottom faces of the head lugs are ‘faced’ to give perfect alignment to the bearings.
This took a sliver off the rib anyway so many builders filed the rest of the rib away and polished it into the the face of the lug as can be seen below left.




One aspect that is quite remarkable about the Nervex Pro design is that it remained popular for such a long time. It appears to have been in use by 1950 yet it was still available on Mercian frames as late as 2004 - the King of Mercia model could be ordered with Nervex Professional lugs for an additional £45 in that year, although they had very few sets left.




Nervex Legere lugs and frame parts
No mention of Nervex lugs would be complete without reference to the Nervex Legere series lugs, of which there were reportedly more than forty variations. Again, Legere lugs were prolific amongst English and European frame makers and some of the Legere designs clearly had a family resemblance to the Pro series. However, although the Legere and Pro lugs were both of pressed steel to 'an exclusive process', the Professional lugs were listed at almost double the price. The 1961 catalogue produced by the UK importer Evian GB  lists the Legere lugs at eight shillings a set (when ordered in a box of 50)  whereas the Pro lugs were fourteen shillings and threepence (or eighteen shillings including the Nervex Pro fork crown). Quite why there is such a large price difference is not clear; the Pro series is not that much more complicated in design. It may be that the steel used for the lugs and/or the bottom bracket shell was of a higher grade. If you have the answer, please let us know.

Incidentally, a complete set of Nervex lugs included two head lugs, a seat tube lug, a bottom bracket shell and a Nervex transfer. The company also supplied many other frame building parts including fork ends, pump pegs, fork crowns, cable guides etc. The high extra cost of the Pro fork crown explains why this item was rarely used.

On the right is an example of a Nervex Professional lug as modified by the builders, Hawkes of London.
 The front of the lugs have neither the telltale 'fishtail' nor the 'horns'.  The lug has been carefully re-profiled to produce a simple curve.

A future for Nervex Pro lugs
Although the Nervex Professional lugset has been out of production for many years now its status can be judged by the fact that in the USA production of an almost identical lug, the Newvex lugset, with a name so similar you have to look twice to see the difference, seems to be heading for success. It is not identical, however, as it has been designed for oversized tubing and also has an 18mm projection at the top of the head lug.

New unused sets of the original French-made Nervex Pro lugsets occasionally resurface from the depths of old workshops and sheds from time to time so frames are still being built today with these lugs - more than fifty years after they were first produced. It is a lugset that has stood the test of time and few would argue that it looks as attractive today as it did back in the days when the Continental stars were winning races on Nervex Pro eqipped machines in the 1950s.



Technical Jottings on Nervex lugs
By Peter Brueggeman

Some useful termsFor Nervex lugs, the feature cut of a lug or lug set refers to the head lugs, and is seen at the front and sides of the head lugs on the head tube. The nozzle cut of a lug or lug set is seen where the down tube, top tube, and seat tube enter a lug, whether head lug, bottom bracket, or seat lug.

From an October 1958 Nervex catalogue from Evian (GB) Ltd, "To reference the 'model' of lug set... select the feature cut and this will form the first part of the reference. Select the nozzle cut and this will be the second part of the reference. Thus, lugs required with feature cut number 83 and nozzle cut number 172 will reference as Model 83/172." The 'feature cut' pattern is seen on the front of the head lugs and the 'nozzle cut' pattern is seen on the seat lug, bottom bracket, and the downtube and toptube ends of the head lugs.

The Nervex Professional lug set is referenced as model 49/162, with Pattern 49 and Pattern 162 exclusive to the Professional lug set. In this 1958 catalogue, Nervex Professional feature cut Pattern 49 is comprised of the familiar fishtail shape at the front of the head lugs and the familiar side profile of the head lugs. Nervex Professional nozzle cut Pattern 162 is the familiar profile on the downtube and toptube ends of the head lugs, and on the bottom bracket and seat lug.

Serie Legere lugs were available in stock with several nozzle and feature cut combinations, and customized combinations from many nozzle and feature cuts were available on request. Serie Legere lugs were available for a ladies model frame. This catalogue doesn't discuss the manufacture details of the Serie Legere lugs but it does mention some manufacture details of  the Professional lugs. One could assume by this omission that the Legere lugs lack these manufacture details noted for the Professional. For the Professional lugs the catalogue says they are "...made to close tolerances, and re-inforced at the bends and around the rim of the head lugs for increased strength.   ... the feature cuts are ... thinned out ...".


In this catalogue, the Professional lug set is shown with two different feature cut fork crowns. One is a "Professional Racing Feature Cut No. 5" fork crown (right); it is noted in text as having a narrow head and being for oval fork blades.  This fork crown is sixty millimeters between the fork blades.
 The other is a "D/B. Randonneur Feature Cut No. 7" (left) "Sport and Tourist" fork crown; it is noted in text as ½ Ballon (wide head) and being for oval fork blades.   The Sport version of the Feature Cut No. 7 fork crown is also sixty millimeters between fork blades but the Tourist version of the Feature Cut No. 7 fork crown is 68 millimeters between the fork blades, seemingly for wider tyre and/or mudguard clearance.  It is assumed from the use of the word "Professional" that the Professional Racing Feature Cut No. 5 fork crown is exclusive to the Professional lug set. The D/B Randonneur Feature Cut No. 7 fork crown is displayed among several fork crown patterns in this catalogue and it is assumed that it is not exclusive to the Professional lug set due to the lack of the word "Professional" and its "Sport and Tourist" designation.

The Professional lug set "is made for Gents frames only," for English and French tubing sizes, and in four frame design angles: No. 1 with top angle 75 degrees and bottom angle 58 degrees; No. 2 with top angle 75 degrees and bottom angle 59 degrees 30 minutes; No. 3 with top angle 72 degrees and bottom angle 61 degrees; No. 4 with top angle 72 degrees and bottom angle 59 degrees 30 minutes. A Nervex Professional lug set came with a Nervex Professional frame transfer.

Building a frame with the Nervex lugs by Norris Lockley (including some history of the origins)

I am/was a framebuilder and I still do have several full sets of these lugs in stock so I am always interested in seeing what other builders think of them and how they have adapted them. This article is sent to add a little bit of the historical background to the company and the development of the Series Mk1 and II of the Nervex Pro set. 

In the late 40s and early 50s most British framebuilders relied upon cast lugs with which to build their frames. These could be from English manufacturers such as Vaughan, Davis, Brampton, Chater Lea etc or from European manufacturers such as Aerts, or EKLA.  As the European economy picked up after WWII supplies of more modern lugs started to be imported, most of which were made from precision pressings of mild steel plate by a process called "emboutissage".  Amongst the very first of these, and very popular with builders, were the excellent Oscar Egg "Super Champion" models. By about 1953 builders such as JRJ in Leeds (later to become Bob Jackson cycles) were also offering the Nervex range of lugs as an option to these other brands. JRJ also offered, as did several other builders that I know of, the Franco-Suisse range.

I started helping a frame-builder in about 1953/54 and up until that time I had not heard of Nervex lugs, but was aware of Franco-Suisse. My recent research, as demonstrated by the Franco-Suisse advert, from February 1950 (see image left), indicates that in fact the two brands were one and the same, Franco-Suisse, a firm in St Etienne, France, being the manufacturer, and Nervex being the brand of lugs that it manufactured.

It would appear from further research that Ste Franco-Suisse either sold out to, or changed its name to Francolam, the name that appears on the box of lugs in the main Nervex article, and on the cover of the much-quoted and referred-to Nervex lug and parts catalogue for 1957.

Although the Nervex Pro MkII lug set, with its fish-tail design, has proven popular for the best part of fifty years, the fork crown, with its two short prongs, has not caught cyclists' imaginations to the same extent.  It is only in the last ten years that I have actually bought some of these crowns as NOS, and so I have no idea how much they cost originally. My own theory about their lack of popularity is that the crown was an early pressed model made by Franco-Suisse, to match up with the head lugs of the Pro MkI lugset, that also had two short spikey prongs. Whether or not what is now referred to as the Nervex Pro Mk I lugset was actually at the time known as the Franco-Suisse, I can only conjecture. Perhaps the Nervex Pro Mk II with the fish-tail feature was the first lug produced by Francolam and marketed under the Nervex name. I doubt that we will ever know the full story

  

The  Pro crowns are in a sense a triumph of "emboutissage" but the method of manufacture did create two gaping cavernous holes inside the crown that it would have been impossible to fill with brazing alloy. Even a well-brazed crown would only have line contact around the perimeters of the holes and along the fancy cut-out and tangs resulting in a somewhat weak construction. On the other hand, around the early 50s, companies such as EKLA and Wagner had started producing very strong accurately cast steel models that gave full contact areas for brazing between the column, fork blades and the crown itself. Any self-respecting frame-builder would prefer to use either cast or forged crowns, they resulted in much stronger and better performing fork units that were less likely to bend in use or from which the blends could not work loose due to the lack of brazed area and contact.

From the frame-building point of view, builders found the Nervex Pro Mk II set to be very good in that it offered a hand-cut look without having to expend  the time and effort of drilling and filing, and yet it lent itself to being altered and embellished in several ways. The other advantage, one that should not be overlooked, was that the sets were offered in a variety of angles that either suited frames straight out-of-the-box, or could be adapted with little effort. The practicality of using the lug was, however, quite different because, fresh out of the box, all the lugs needed quite a lot of attention to clean up the stamped-out curved profiles that often appeared to have been nibbled rather than cleanly cut. This criticism applied particularly to the three pipes, i.e. those tubular parts that held the top and down tubes.

Internally the lugs were very accurate in their angles and diameters, with very few and only small voids in the junctions between the upper and lower mitres. The side inner profiles of the mitres were reamed very precisely, thereby eliminating any sloppiness of fit. The closeness of internal fit meant more accurate frames and also the need for less brass to fill voids and less heat to apply it and to make it run into those voids, i.e. backfilling of the joints.

However this accuracy came at a price, that being that the pressure applied on the external surfaces by the machines forming the lugs, often left deepish grooves along the mitres. Some builders would spend hours filing the whole of the pipes to reduce the thickness of the metal in attempts to obtain a smoother overall finish, while others would run lines of bronze welding into the grooves and then smooth this into the pipes.

The real labour of using Nervex Pro lugs was the time it took to thin down and taper the pipes either in preparation before brazing, or afterwards when cleaning up and finish-filing. Those litte squiggles and swirls, particularly the fish-tails central to the head lugs, took a lot of skill and care, if a neat and harmoious effect was to be obtained.

Modified Nervex Professional lugs:
Some builders would take the Nervex lug, in this case a Professional, and then re-profile or add brazed-on flourishes.  Shown below are such lugs from a Holdsworth Whirlwind Special frame.  This frame would have been built to special order as Holdsworth had stopped building frames with fancy lugwork in the mid-60's. By comparing these lugs with the Professionals above it can be seen where the additions have been brazed on at the front of the head tube and on the top of the top and down tubes.   Thanks to Hilary Stone for images and information.

John Crump's 1950 Mercian 'Viglorelli' with long tangs added to the Nervex Professional lugs on
the underside of top tube and down tube.  
He tells us that Mercian catalogue he has does mention Super Bi-laminated on all lugs with 3" extensions under all tubes 

Left is a Nervex box which will hold a complete set of lugs.  Some builders could well stock 50+ boxes of each type of lug.  The Professional though was by far the most popular.  When the market collapsed in the fifties obviously many builders were left with lots of these lugs which is why they were available until quite recently.  Even now the odd set surface to the delight of the lucky purchaser.   Below is what the builder found when he opened the box ready to start the build - compare the edges of the lugs with the carefully filed edges created by a skilled frame-builder: