26 February 2016

Curls, Splits And A Flying Gate

In the 1880s, J.K. Starley developed his "Rover" Safety Bicycle.  Nearly everything I've read about the history of cycling pins the Rover's importance to the fact that it had two equal-sized wheels and a chain-powered drivetrain.  This innovation was indeed an improvement, in many ways, over the "penny farthing" or "high-wheeler" bikes that had large front wheels (as much as 72 inches) with cranks and pedals attached to the axle, and a much smaller rear wheel.  The Rover was indeed safer to ride and its drivetrain allowed for variations in gearing, something that was not possible on the fixed drivetrain of the "penny farthing."

A later version of the "Rover" featured another innovation that isn't mentioned as frequently but might have been just as important.  Its frame had a configuration which we would now recognize as the "diamond".  Nearly all racing bikes, and most everyday bikes that weren't specifically designed for women (and even some that were) have incorporated this design feature.   Even bikes made with the most exotic materials owe their most important design feature to a bike that was made 130 years ago.

Even "mixte" and some "women's" bikes can be said to be variants, in one way or another, of the "diamond" frame.  In fact, one might even argue that "step through" frames are variants of the "diamond" because they are usually made like diamond frames without  a top bar (and, in some cases, with wider-diameter down- and seat-tubes to compensate).

Over the decades, there have been attempts to render the diamond frame lighter, stiffer, more efficient or, perhaps, just sexier.  Some seem to recur every generation or so. 

One of the more interesting variations was the Hetchins "curly stays" frame:



The late, great Sheldon Brown rode the Hetchins in the photo.  There was, believe it or not, a reason for those stays.  In the 1930s, races were often run over rough roads or even cobblestones.  Curved forks absorbed some of the shock in the front.  Straight rear stays, on the other hand, transmitted the road shocks, which caused the bike and even the rider to rattle and shake.  That, in turn, resulted in wasted motion. (Think about that the next time you hear "stiffer is better"!) 



So, the idea of curling the rear stays was so that they would replicate, on the rear, what curved forks did in front.  I guess there is something to that idea:  After all, mountain bikes with rear suspension can go faster because they're more stable on rough terrain. 






Whether or not curly stays offer an advantage to a loaded touring cyclist is debatable; there doesn't seem to be any advantage to them on the track.  Still, there were track bikes with curly stays and other unconventional designs because builders weren't allowed to "advertise" on their bikes.  Hence, decals, transfers and other markers bearing the builder's or manufacturer's name were not permitted.  So some builders--like Hetchins--called attention to their bikes with unusual designs.


Another variation on the diamond frame is the split seat tube that was a feature of bikes like the Rigi of the late 1970s and early 1980s:



As you can see, this design, by allowing the tire to run between the twin lateral seat tubes, shortens the bike's wheelbase, which makes for faster acceleration and greater rigidity.  I had the opportunity to try a Rigi and it did indeed feel stiffer in the rear and had more of a "jack rabbit" feel than other bikes I'd ridden.  The Rigi I tried was a road model; I can only imagine how a track model would have felt!


 

 


I found myself thinking about those bikes when I came across this: 





Baines Brothers of England made the "Flying Gate" frame from the early 1930's until the early 1950s.  Baines Brothers didn't actually call their frames "Flying Gate"; rather, it's a nickname the bike acquired because of its shape.



As with the Rigi, one justification for the design is that it shortened the wheelbase to 100cm (39.5 inches), which was all but unheard-of on a road bike at that time. 



Ironically, even though the frame was intended for road use, it seems to have track ends on it.  Maybe they had the same idea I had in mind when I built Tosca, my Mercian fixie:  a responsive fixed-gear bike that could be ridden on the road.  Perhaps whoever rode the bike set it up with a "flip flop" or double-sided hub, as was common on British "club bikes" of the time.

 

From what Hilary Stone says about these bikes, the model in the photos is probably a later one, as the earlier ones--like most bikes from the '30's--used relatively plain lugs. 

Trevor Jarvis acquired the rights to the design and produced a number of frames at his TJ Cycles shop in Burton-on-Trent during the late 1970s.  Though most were made for time trialing, his shop produced, interestingly, a touring model.  In a way, it makes sense, for one complaint many cyclists have about traditional touring bikes is that their long rear triangles and wheelbases cause them to handle like lumber wagons.  Of course, one problem with riding a short-wheelbase bike for loaded touring is that your heels get caught in the panniers and the vibration transferred through the stiffer rear triangle makes the bike less stable and tires the rider on rough surfaces.

According to Stone, riders generally appreciated the responsive ride offered by the "Flying Gate."  I would be curious to try one myself!

4 comments:

  1. the baines letters are tremendous, love it

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    1. Meli--Yes, they are tremendous--and somehow soo British!

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  2. I wonder if that Baines was intended as a "road-path" model, which might explain the rear facing fork ends in back. That was a pretty common configuration in those days. Ride the bike to the track, remove the brakes and mudguards, flip the hub around, and ready to race.

    The angles on that Rigi are so steep! With those angles and that super tight wheelbase, I'll bet that thing would change direction if you sneezed.

    Another interesting variation was the Bates bicycles with the "cantiflex" tubing (larger diameter in the middle than at the ends) and "diadrant" forks which had almost an S-curve in the fork rake.

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  3. Brooks--That's a good point about the Baines. Given the time in which that bike was made, it may well have been a "road-path" model, as such bikes were popular in the British Isles then.

    To say the Rigi "would change direction if you sneezed" almost isn't an exaggeration. I know; I rode one, and it was probably the twitchiest road bike I ever rode.

    I haven't seen those Bates bikes in person, but I've seen references to them. It would definitely be interesting to ride one!

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