The Flash Hub Is Gone--Or Perhaps It Never Came!

What is this?

No, it's not a vintage Campagnolo Record front hub retrofitted for disc brakes. (Oh, perish the thought!)  Instead, it's something I mentioned in an earlier post:

It's none other than the Cinelli Bivalent.  It may be the only hub in history that was designed to be used either on the front (as shown in the first photo) or the rear. 

The toothed wheel served no purpose on the front. On the rear, however, the gear cluster or cassette fit onto it.  This was supposed to make wheel removal and installation easier.  From what accounts I've heard and read, it seems to have fulfilled that purpose.

Being a Cinelli item, the quality was most likely excellent.  (Some have claimed that Campagnolo made the hubs for Cinelli.) When the system was introduced during the early 1960's, the hub had a three-piece shell, like most hubs of that time.  A few years later, Cinelli started to offer hubs with single-piece alloy shells.

Although it seems that those who tried the Bivalent liked it, the system never caught on.  The reason usually given is that racers didn't want to use it because if they had to replace a rear wheel, a support van or truck probably wouldn't have another on hand, and the threaded hubs (like Campagnolo's) almost everybody--including all racers--used at the time wouldn't work with it. 

(That, by the way, is also one of the reasons why Campagnolo Record (as well as Nuovo and Super Record) dominated the peloton for so long:  Everyone wanted equipment that was compatible with everyone else's.)

As I mentioned in my earlier post, during the ensuing two decades between the introduction of Bivalent and Shimano's Freehub system (the prototype of every cassette hub made today), there were other attempts to make something more convenient, versatile or stronger than the traditional threaded hub and screw-on freewheel--especially since manufacturers were adding more gears to bikes.  

One of those attempts was SunTour's UnitHub of 1969.  Like today's cassette hubs, it combined the gear carrier and hub into one unit.  From what few accounts I could find, it worked well and was sturdy. However, the public wasn't ready for it--just as it wasn't able to receive another SunTour debutante from that year, the Five-Speed Click indexed derailleur system.

A decade later, Maillard introduced their "Helicomatic" hub, featuring a bayonet-style mounting onto which a gear cluster mounted.  The idea was great (better, I believe, than the Freehub system or any of its descendants), but it was poorly-executed and thus prone to breakdowns.  Shimano brought out its Freehub around the same time and, as the saying goes, the rest is history.

But there was, apparently, an attempt to resurrect the idea of the Bivalent.  A company I had never heard of until I encountered it on Michael Sweatman's Disraeligears site made it--or, at least, made plans for it.  No one seems to know for sure whether any of those hubs were actually made.

The company, EGS, was based in France.  It made one of the most elegant or extravagant, depending on your point of view, and certainly most futuristic derailleurs ever created:  the UpCage.   In essence, it was a classic SunTour derailleur with its pulley cage mounted horizontally and a tensioning arm between the body and the pulley cage.  They weren't in production for very long, even though they were much loved by French downhill racers.

EGS UpCage.  From Disraeligears

Apparently, ESG had big plans:  its website--still up even though the company went belly-up in 2000--shows plans for a "Syncro-Shift" twist-grip control that operated both the front and rear derailleurs.  (Whenever I see any form of the word "Syncro" in a bicycle or component's name, I turn and ride as far and fast as I can from it!)  Also on EGS's drawing board were a brake system and something they called the "Flash Hub."

From the EGS website

ESG's website says the Flash Hub was to consist of a two-part hub, a fixed cassette mount and a moveable wheel mount.  The cassete mount unit was made to stay fixed to the frame's rear fork end.  I can't help but to notice their use of the term "fork end", which just may be a matter of translatation. Still, it leads me to wonder whether it would have worked with vertical dropouts.  No matter:  This system, according to ESG, would make it "child's play" to change the rear wheel.

There is no mention that the hub could be used on the front, so I imagine it wouldn't be possible.  To be fair, when Cinelli came out with the Bivalent hub, many frames made for derailleurs still had 110 mm spacing in the rear, as most freewheels still had no more than four gears.  Most road bikes then, as now, had 100mm spacing in the front fork.  So it probably was easier to make a hub that fit both front and rear than it would be to make such a hub now, when rear spacing is typically 130 or 135mm, and could grow if twelve or more gears and disc brakes become standard equipment.

Still, I have to wonder whether those guys at ESG--who, it seems, were downhill racers or had the attendant mentality-- knew about the Bivalent hub. 

N.B.:  Cinelli Bivalent photos were taken by Al Varick and appear on Classic Rendezvous.
 

Shifting Gears--Literally

When I first became a dedicated cyclist--around the time that the '70's North American Bike Boom was peaking--all derailleur-equipped bicycles had gear clusters (freewheels) that screwed onto the rear hub.  

Cinelli Bivalent Hub, circa 1961

That is, all of the derailleur-equipped bicycles I saw.  I'd read and heard about the Cinelli Bivalent hub, which was produced for a few years during the 1960's.  Other than that, I believed, there was only one sprocket system for derailleur-equipped bike, and your only concern was whether the hub had British, French or Italian freewheel threads. 

And, as far as I knew, the first departures--apart from the Bivalent--from such a system came around 1980, when Maillard introduced its Helicomatic system and Shimano came out with what was then called the Freehub.

Shimano 600 Freehub system, circa 1981

Shimano's system was essentially the same any of today's hub-and-cassette systems, save for those of Campagnolo, which have a different spline pattern.  The only major difference between those early Freehubs and today's Shimano and SRAM ensembles is that the on old Freehubs, which had six cogs, five cogs slid onto splines and the smallest one screwed on, acting as the lockring.  On current hubs, all of the cogs are joined as a cassette that mounts on the splines and is held in place by a separate lockring.

Helicomatic.  From a 1984 Peugeot brochure

When I first saw the Helicomatic, I actually thought it was a better idea than the Freehub.  I still do, and I think it's a better concept than any of today's hubs with cassette bodies.  The problem with the Helicomatic--as with another "revolutionary" French component of the time, the Huret Duopar derailleur--is that while it was a great concept, it wasn't well-executed.  Maillard offered lower- and higher- priced models of Helicomatic, and they suffered from the same problems:  soft helical spines (the "bayonet" mount) that often gouged or stripped, rather weak axles that frequently broke and, on the racing model, smaller-than-normal ball bearings that caused the cones and races to wear quickly and, in a few cases, "explode."

But the Bivalent, Helicomatic and Freehub were not the first systems to depart from the screw-on freewheel cluster.  Just recently, I became aware of another, which also employed its own unique rear derailleur.

In the early 1930s, Alex Shuttleworth and William Hill paptented the TriVelox system.  It had three rear cogs--which was all most derailleurs of the time could handle.  It also used a 1/8" pitch chain,  in contrast to today's 3/32" derailleur chains.  

But most improtant of all, the TriVelox derailleur--unlike those of today--shifted gears by moving the sprockets rather than the chain.  Apparently, the sprockets were fitted onto splines, much like the Helicomatic or Freehub cassettes. And the derailleur remained fixed while the freewheel block moved sideways on the hub.

Why was such a system developed?  It was a response to, as Michael Sweatman of Disraeligears says so eloquently, "a peculiarly British fixation with chainline".  British cyclists, by and large, shunned derailleurs--as they would until the 1950s--because using them meant running the chain out of line on the extreme gears (small chainring with smallest rear cog or large chainring with largest rear cog).

As Sweatman tells us, they had a point.  Roller chains are meant to run in a straight line.  Thus, while riders in Albion had an exaggerated fear of the friction incurred by running a chain out of line, they were correct in believing that chains wear out more quickly when they're run out of line, let alone bent and flexed when shifted on conventional derailleurs.

Bicyclists of that time had good reason to think about longevity:  Chains were comparatively much more expensive than they are now.  That is why people were more fastidious about keeping their chains cleaned and lubed--and why many bikes came with oil-bath chain cases, something that couldn't be used with a derailleur.

The TriVelox system did what its creators intended.  Walter Greaves rode such a system for 45,000 miles (!) in one year and used only two chains and two sets of sprockets.  In other words, his chains lasted about ten or fifteen times as long as a chain made for a current 10- or 11-cog system.

TriVelox seems to have been in production for about two decades.  It was never a mass-market item, but it had its following, particularly with tandem riders.  One reason why it didn't become more popular is that it was much heavier than conventional derailleur/freewheel/hub combinations.  Another is that the system required a very wide rear axle to accomodate the sliding freewheel system. That, of course, limited its development to three speeds because additional cogs would have required an even bigger axle.

But most important of all, by the 1950s, most dedicated cyclists were realizing that derailleur systems were reliable and practical, and would allow for more than three cogs without widening hubs or axles.

I came across a TriVelox set on eBay.  I'd be very curious to see it--and other predecessors of today's cassette-and-hub systems--up close.