Is the beauty of a bicycle in the way it rides, or the way it looks?
Mon, October 14, 2019 When I built my first frames in England in the late 1950s, early 1960s, I was trying to build myself a better frame. A typical frame of that era had a very shallow, 71-degree seat angle and a long top tube. This did not suit my small stature of 5’ 6”. (167.64 cm.)
When making a maximum effort, I found myself sliding forward and consequently sitting on the narrow nose of the saddle. The result was it was extremely uncomfortable and had the effect of the saddle being too low.
The answer seemed obvious to me, if this was the natural position my body wanted to adopt, put the saddle where it needed to be to accommodate it. I also looked at the way the bike handled at speed, there was a tendency to wobble on fast descents. Also, the bike tended to feel sluggish when getting out of the saddle sprint, or to climb.
Over the next 10 or 15 years I built several different frames with varying angles, and each frame had extra front forks of various rakes, (Offset.) Some of these experiments improved the bike’s performance, and others made things worse. It was a long, slow learning process.
By the early 1970s I had pretty much got my own frame geometry figured out. But now I was being asked to build frames for other local cyclists. By now the trend in Italy and in England was the build road frames with 75 or even 76-degree head angles. I went against this trend as I had experimented with these angles years before and found it did not work too well. The handling was skittish or squirrely.
73-degree head had been established as the ideal head angle as far back as the 1930s, and it still worked. However, the old idea was to have a very long fork off-set, and zero trail. This is what lead to the speed wobbles of those old bikes. I had found that I ¼ inches (32 mm.) fork rake worked better and finally settled at 1 3/8 inches. (35 mm.)
With feedback from other riders, I found that a 73-seat angle worked fine for the taller riders, but I would gradually steepen the seat angle as the frame got smaller. The top tube was lengthened as the frame got taller, but at a lesser amount that the seat tube. This was offset by a longer handlebar stem on the larger frames. The idea was to always have the front part of the handlebars directly over the front hub. This meant the handling was consistent throughout the range of sizes.
Having spent many years designing and building a better bike, it became my main selling point.
Here was a frame that would fit better and handle better. (See the advert (Left.) from the British Cycling Magazine from 1975.)
Strangely, I have seen few framebuilders or manufacturers advertising their product on the premise that it rides and handles better than their competitors.
I feel proof that my frame design is valid, is the fact that I still have a following 26 years after I built my last frame. Many owners are original owners and will not part with their bike. I regularly receive emails from owners saying their FUSO or other bike I built is their favorite ride.
I was recently asked, “What do I think of the current American builders?” I don’t really know enough to answer that. I only know what I see at NAHBS each year. I see beautiful pieces of art, outstanding paint and metal work, but how do they ride? Or does anyone even care? No one will ever go out and race on such a machine anyway. Race bikes are no longer made of steel.
As far as I can see, the corporations who today build the carbon fiber bikes that are raced, are doing little that is innovative as far as geometry. They still build the basic 73-degree parallel frame that dates to the days when it was easier for a builder to build a lugged steel frame that way.
It is difficult to find a CF fork with a 35 mm. rake anymore. Today frames come out of a mold, angles and geometry could be unlimited. Within UCI rules of course, but even within those rules there is room for change. The UCI will also follow what the manufactures want. Disc brakes was an example of that.
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Reader Comments (5)
I’m always surprised by the relatively short offset and corresponding high trail of most road bike frames. My experience is that most of these bikes run wide on corners. Maybe it’s my riding style, but I’ve always preferred the low or lower trail bikes which in my experience turn in more quickly and corner better as a result. I’ve never had a problem with shimmy from these bikes. Especially when using a roller bearing headset. I believe Eddie Merckx preferred lower tail bikes, something in the order of 49 mm, because of their superior performance on cobble stones and their manoeuvrability, but don’t know if this is true.
Mark,
Eddy Merckx mostly rode bikes built by Ugo DeRosa and as I mentioned in the article Italian bikes of that era had steeper head angles and therefore less trail. As for Merckx preferring this, throughout history professional cyclists have always ridden whatever their sponsors provide for them.
In Europe, lugged steel frames were traditionally built with a head angle 2 degrees steeper than the seat angle, because it made it easier for the framebuilder. As the frame got taller,the top tube got longer. Hence 73 head, 71 seat in the 1950s and 75 head, 73 seat by the late 1960s and 1970s.
Also during this same period the parallel angel frame became popular 72/72 and later 73/73 because simple fixed jigs could be used, and the same length top tube used over several sizes.
It has always been what is easiest for the builder, I could have followed that route but chose not to. My point is now that frames are molded CF there are no such limitations but manufacturers take the "Safe" and easy route of building what has traditionally worked in the past.
Dave
Ever since the early 80's, I've looked for frames that were 73x73 with a 58cm top tube (occasionally a 59cm). depending on the bar reach, I'd use a 13 or 14 cm stem (I'm 6'2" tall) Back in the 80's and 90's, top tubes were always parallel to the ground. Since 2000, most frames have a non-parallel top tubes. Since they always give a virtual top tube length, it's still easy to pick a frame (as long as you look at the head tube length)
I'm quite entertained by this discussion, I think because I come at it from a third angle - a bicycle is beautiful for what it does. The bikes/frames I've built have all been experiments that don't measure up to anyone's standards of beautiful looks (not even mine) and often don't ride especially well. But they do things you just can't get in any other bicycle. And if they lead customers to demand similar functionality from commercial builders, all the better :)
I'm also quite on Mr Moulton's side with regard to the actual topic of the post, though, it has to work as a bicycle before it can be considered a beautiful bicycle.
I will admit I'm intrigued by Dave's use of shorter than common fork rake and would love to try the design some day.
Typical fork rake in today's 73 degree head angle world is 43-45mm.
In my experience with a smaller frame and a 73/45 combo, while I didn't experience shimmy, I did experience the bike being easily tossed around in blustery winds.
I had the opportunity to own a bike with a 73/50 front end. That low trail bike sucked.