The ideal handling bicycle

Back in the early days of my framebuilding career, mostly in the 1960s; I was experimenting with head angles, fork rake, and trail.

It was in the days before electronic calculators, and computers, so I kept track of my progress with a graph drawn by hand on squared graph paper.

It looked something like the graph above, only it would have been in inches rather than centimeters. Today there are online trail calculators available.

Trail not only gives a bike stability and keeps it tracking on a straight line, but also gives it self-steering qualities.

When you lean into a corner, the bike will for the most part steer itself around the bend.

Because the bike and rider are leaning, the rider’s weight is being pushed outwards and downwards by centrifugal force, thereby actually pushing the tires down onto the road, which increases traction.

However, there is an optimum amount of lean, too much and the bike will slide out from under the rider. Therefore there is an optimum trail, if a certain amount of trail is good, more trail is not necessary better.

The amount of trail is not the same throughout a range of different head angles. The steeper the head angle the more sensitive the steering, therefore less trail is needed to have the same effect as it would on a bike with a shallower head angle.

In time I found there was an “Optimum Handling” line that I could draw on my graph, that would show me the fork rake needed for a given head angle.

Reading vertically down from where the fork rake line crosses the head angle line shows the amount of trail. As you will see, steeper angles, less trail; shallower angles, more.

The example shown 73 degree head, 35 mm. fork offset, and 67.3 mm. of trail, was my standard road geometry on the John Howard, Fuso, and Recherche frames I built.

I would build a track bike with a steeper head angle (75 degrees, 25 mm. rake.) making for  more sensitive steering because it is designed to be ridden on a banked velodrome.

The banking has the effect of riding in a straight line, not cornering like a road bike. The rider needs a bike that he can physically steer around an opponent in a quick move.

Also in the event of another rider falling in front of him, he needs to be able to change direction in an instant. This was also my thinking, when I built a criterium frame with a 74 degree head, and 30 mm. of fork rake.

However, my standard road geometry gave this same ability to lean into a corner, let the bike take you round, but if you needed to correct your line, or steer around an obstruction, you can physically steer the bike by turning the bars, and pointing the bike in the direction you need to go.

I have said before, my bikes had a little more trail than most others built back when I was building, and more than on bikes produced today. That is not to say I am right and all others are wrong, it is just my design philosophy is different.

Also the handling qualities of a bike do not depend on the steering geometry alone; it is the design of the whole frame, weight distribution, etc., etc.

When I recently rode a carbon fiber bike I bought for my wife, I liked the way it rode, but the steering was different. Not bad, nothing I could put my finger on, or nothing that I could not get used to, given time.

My philosophy has always been, build a good handling bike; put a novice on that bike and he becomes an adequate bike handler. Put an experienced bike rider on the same bike and he becomes a brilliant bike handler

                       

Fashion Faux Pas

In 1981 when working for Masi in Southern California, I went to a bicycle trade show in Atlantic City, New Jersey.

Falerio Masi, founder of the company, flew over from Italy and met us there on the opening day. When I arrived at the Masi show display from my hotel that morning, Falerio was already there and very upset.

He was speaking in Italian through an interpreter and flicking angrily with his finger tips at the brake cables on one of the bikes on display. I did not need to know what he was saying; I knew exactly what the problem was and why he was angry.

The bike was set up (Similar to the bike pictured above.) with the brake cables running under and in front of the handlebars. This was a huge fashion Faux Pas in Europe, it drove me crazy too.

Brake cables were supposed to flow in a pleasing curve from the brake lever, to the front brake, and to the top tube en route to the rear brake. The brazed on cable guides were precisely placed along the center of the top tube to facilitate this.

I heard Falerio Masi told,

 “It is no big deal, and Americans don’t care about such things.”

That statement was probably true at the time. Many bikes being sold and ridden in the US were bought by people who today would buy a Mountain Bike, or a Hybrid. They were often set up like this Fuso (Above.) that came up for sale on Craig’s List last week.

Frames were usually too big for the rider. (By European standards.) The result was, the saddle was too low, and usually the bars were set too high. The brake levers are set too high on the curve of the handlebars, and the levers start to stick out front like a pair of six-guns.

This all indicates to me that the rider never should have been on a dropped handlebar bike in the first place, and I would rather have seen this bike set up with flat handlebars than set up looking like this.

On an “Old Skool” bike, the external brake cables were an important part of the aesthetics of the overall look. On my own bike for example (Above, and close up below.) notice how the cables leave the brake hoods, following the same curve of the lever.

Notice how the rear brake cable flows from the brake lever to the first cable guide on the top tube. It doesn’t matter if the front brake is on the right or the left, that is a personal preference.

The top of the curve of the cables just happen to be level with the top of the saddle, which has nothing to do with anything. However, this being my correct size frame, the handlebar to saddle height ratio is also correct, this is most likely the reason why it turned out that way.

Because when form and beauty meet function, there is harmony and balance. A  machine set up to perform correctly from a functional stand point, will also look right from an aesthetic view point

                     

The Evolution of Frame Design. Part I: The Wheelbarrow Effect

The picture above is Italian cyclist Giuseppe Martano, seen here on his ride to 2nd place in the 1934 Tour de France.

Probably the first thing most will notice is that the bike has a single fixed sprocket. Gears were available at that time; however, Tour de France riders were restricted to a single speed at the whim of Tour organizer Henri Desgrange.

Desgrange felt that multiple gears were for bicycle tourists, and they took away from the purity of the sport of cycle racing. So riders had to struggle over the same mountain climbs the Tour currently goes over, with a single gear, on roads in far worse condition than today.

The other thing you will notice about the bike is the long wheelbase, some 4 or 5 inches (10 to 13cm.) longer than a modern race bike, the shallow frame angles, and the long curved front fork blades.

One of the reasons for the long fork rake or offset, was always thought to be because roads were so bad back then; in most European countries little more than dirt roads.

The long curve of the fork would allow the fork to flex acting somewhat as a form of suspension.

However, there was another reason; a long held theory that trail made the steering sluggish on a bicycle.

If you look at the drawing (Above left.) an imaginary line through the center of the head tube, (Steering Axis.) reaches the ground at the point of contact. On a bike from this era, there was zero trail.

On a modern bike (Drawing right.) the point where the wheel contacts the road will be some 2 to 2.5 inches (5 to 6.3cm.) behind the steering axis.

Hence the term “Trail,” because the wheel trails along behind the steering axis.

Bicycle geometry did not change much from the 1930s until the 1950s when I started racing.

Standard road frame angles were 71 degree seat angle, and 73 degree head angle. This was true for any size frame.

Frame lugs were heavy steel castings, machined on the inside to accept the tubes at these standard angles. It was not cost affective to make lugs in different varying angles. It was established probably around the 1930s that 73 degrees was the ideal head angle for a road bicycle; this is still true today.

The reason for the seat angle being 2 degrees shallower was because when a framebuilder made a larger frame, the top tube became longer because the head and seat tubes were diverging away from each other.

These standard angles were not for the benefit of the rider, but for ease of construction for the framebuilder.

For a shorter rider like myself, the top tube was always too long and I was sitting back too far.

When I made maximum effort I always found myself sliding forward and sitting on the nose of the saddle. As well as being uncomfortable, it had the effect of the saddle being too low.

Because of the long top tube, I always had to use a short handlebar stem, and this lead to another problem when sprinting or climbing out of the saddle.

The rider’s weight was behind the front wheel’s contact point with the road; due to the short stem and the forward sweeping forks. Out of the saddle, the bike swung from side to side in an arc causing the front wheel to steer first one way then the other; not holding a straight line.

At the same time the gyroscopic action of the spinning wheel was trying to keep on a straight line. So the two actions were fighting each other; hence the bike felt sluggish and unstable.

To demonstrate this effect to yourself; hold a pen or ruler on a table top at 90 degrees to the surface, and move from side to side keeping the point of the pen in one spot; you are moving in one plane. Now hold the pen at an angle of 45 degrees and move from side to side and you will see that you swing in an arc.

This was something I later called the “Wheelbarrow Effect.” In Part II I will talk about how frame design evolved through the 1960s and 1970s to arrive closer to what we see today.

Old bike designs die hard

In my previous post I wrote how the High-wheeler or Ordinary bike influenced riding habits well into the next century. It also influenced frame design into the 1950s and 1960s.

If you look at the top picture you can see, due to the simplistic design of these old bikes, there was a limitation where the rider could be placed. I have drawn in red the three points of contact; the saddle, pedals, and handlebars.

With the steering almost vertical, the handlebars are directly above the pedals. If you can imagine on a modern bike if the handlebars were directly above the bottom bracket, they would be about where the nose of your saddle is.

So you can appreciate that if this were the situation, the rider would have to sit much further back. This was the case on the old ordinary bikes the riders were sitting much further back than we do today.

People do not like change, and as I mentioned in my last piece the cycling enthusiast did not take to the new fangled “Safety” bicycle immediately. It was necessary for those designing the new machine to place the rider in a position he was familiar with.

In the next picture I have drawn a safety bicycle superimposed on the ordinary. I left the saddle, pedals, and handlebars exactly where they were on the high-wheeler. By placing a front and rear wheels in the only logical place, and connecting all the dots, you can see we have a close approximation of a early safety bicycle.

This theory is confirmed by the photos below, showing two riders in almost identical positions; one on an ordinary and one on a “Rover,” the first safety bike.

The next picture below is of Ottavio Bottecchia's bike; an Automoto that he rode to victory in the 1925 Tour de France. In 25 or 30 years the handlebars have been moved forward and lowered, but the saddle position in relation to the pedals has remained as it was on the ordinary. The seat angle is about 68 degrees.

The picture below is of Louison Bobet’s French made Stella that he rode to his 1954 Tour de France win. The angles have become slightly steeper and the fork rake is shortened. However, look at where the nose of the saddle is in relation to the bottom bracket.

This was the way bikes were designed when I started racing in 1952. I was always told by my elders that I had to sit back in order to pedal efficiently. In time I questioned this because I am somewhat short in stature, and found when making maximum effort, I would slide forward and end up sitting on the nose of the saddle.

Studying photos of other riders I could see many had the same problem, this is what started me experimenting with frame design. Initially I was just looking to improve my own performance.

The problem has always been that in general, people who race bikes do not build them, and people who build bikes do not race them. And no one ever questions why certain aspects of design are the way they are.

A Million Bucks? What a Crock*

This is a bike that Koga has developed for Dutch Olympic hopeful Theo Bos. Koga claims they have spent a million US dollars developing this special one off bike.

I’m sorry I don’t buy it, all I see is just another carbon fiber bike. If this was new technology I might be convinced, but CF bikes have been around for twenty years or more, they were built for the Olympics in the 1980s.

It’s a bicycle fer Cri-sakes, not a Formula One race car; where do you get a million bucks. Give us a breakdown of where the million dollars went.

What about truth in advertising? Because this is what it is. You build a one off bike, and then you think of a number. Okay, a million dollars is a nice round figure.

Next, put out a press release saying you’ve spent a million developing this special bike that is so light a fart would blow it away.

The press and the general media, knowing sod all about bikes goes with the story.

When it comes to bicycle racing it is the strongest rider that will win every time. If Theo Bos is the best rider he would still win on a stock bike that anyone can buy.

Can’t Koga see that? If Bos were to win on one of their stock bikes, it would in the end sell more bikes. Because what they are saying is, our stock bikes are not good enough for the Olympics we have to spend a million dollars.

The smart thing to do would be to pay Theo Bos a million dollars if he wins the gold on a stock bike.



* UK translation: What a Crock = What a Load of Bollocks!

Footnote from Dave: Ooops! Koga not Kona, mistake edited. See first comment. Thanks Darren