Machine Bicycle Co.

handmade bicycles.

Understanding how your bike handles.

Kyle Ward3 Comments
Trail80rake.jpg

A lot goes into how your bike feels when you ride it. One of the most important things in how your bicycle feels is how it handles. That means the effects the bicycle has on how you and it move together through space. Like a working Machine. The single most important thing in how the bike handle is the trail.

If their is an imaginary line through the center of the steering tube (Steering Axis.) all the way to the ground and also one vertical through the spindle/axle of the front wheel. (All the way to the ground)

The difference between these two points is what defines "trail". Trail affect steering as you lean the bike to the left or right, the steering axis moves in that direction, and the wheel follows. It pivots on the point of contact with the road.

 

Trail also affects how the bike holds a straight line. It works like a wheel on a grocery cart, which goes in the direction it is pushed. This is why it is called “trail,” because the wheel trails along behind the steering axis.

Generally when dealing with 700-C wheels, a trail of about 56mm will give a frame set "neutral" handling.  While cornering, a neutral handling bike will have neither a tendency to climb out of a turn nor have a tendency to dive into the turn, it will simply hold the line that the rider sets up unless further rider input is applied.

Decreasing trail below the neutral range has a couple of effects. The first thing a rider will notice about a "low trial bike" is that it appears to resist turns. It requires more physical effort to get the bike to lean into a corner and more effort to get it to straighten up. The second thing that you will notice is that while cornering at higher speeds, the bike will have a tendency to climb out of the turn on its own. Finally, you will find that the way the bike responds to rider input is affected by the speed of the bike. At lower speeds, a low trail bike will have a tendency to want to go straight and do so on its own. What you will find at higher speeds (over 30mph) is that a low trail bike will become less commutative with you. The front wheel will feel as though it is wandering a bit and that feeling of knowing where the tire contacts the ground disappears. 

Increasing trial above the neutral range will cause opposite effects. At lower speeds, handling response will be light and easier. Commonly mistaken as quick. During cornering, the bike will have a tendency to drop into a tighter arc than the rider might have intended. Finally, speed's effect on handling is reversed. While low speeds give a light feel during handling maneuvers, high speed sets up a very solid front end feel. Resulting in a hard to turn bike at higher speeds. 

Although high trail frame sets give safer (more inherently stable) handling than low trail frame sets do, high trail frame sets are still inconsistent in the way they respond to rider input. Interpreting from the basics above you can see why we usually aim for neutral trail. It does not require the rider to consciously hold a bike down during hard cornering, nor does it require different rider input depending on changing speeds. The consistency of neutral handling is optimal for riding with others, both in recreation and in racing. Foreword is the way we want to go, fighting any other direction is inefficient.

What is to be said about all of this? Knowledge is power really. As a consumer, you should be educated on this phenomena because the big companies like to use marketing psychology and cover their bases. They usually offer the different feels knowing that if you test ride and pick up on these feelings that cause inherent reactions your bound to choose one. It is hard to know if the people you buy them from know the purposes for each style bike and whether they put you on the right one or not but you should know your goal and purpose for riding. It is ultimately you who can benefit.

This is why I would recommend buying a bike from a framebuilder. A large company has so many employees. Not only do they all have to get paid but they are all their to fulfill a different job. The designers design, the engineers are engineers. Do they ride bikes? Maybe. The manufactures create. Do they ride bikes? Maybe, not likely. They have marketing firms trying to appeal not inform. Sales reps that need to make a commission. They usually ride though.

Anyway its a huge machine of working parts. It's great to have soo many, because it'll still run when some of em break. This is why we are machine, the company. So many working parts. Its me. I pour everything into the bike I design and build and ride. Most framebuilders become framebuilders because of love. Id say most of em have a pretty good fundamental understanding of the bicycle. When they begin building their first bikes they quickly learn everything they need to to make that bike better. The learning curve is steep. I want it to continue.