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Tuesday
May152007

When it comes to bike saddles, how level is level?


The general consensus among experts is that a bicycle saddle should be level. If the nose is pointed up, it will put pressure on the perineum and cause discomfort.

If the saddle is positioned sloping downwards, this will throw too much weight onto your arms. Weight should be balanced between your seat and your hands.

But, how level? I feel to get out the carpenter’s level is over kill. If the saddle appears to be level to the naked eye, and it feels comfortable, to me that is level.

There are also so many differing designs of saddles. On my bike (above) I have a Concor saddle that was popular in the 1980s. Its design is swept up at the back and if I were to place a level from front to back it would indicate the saddle pointing downward, because the back part is higher.

However, visually the part where I sit is level. Unless the top of the saddle is flat front to back, it can’t be level at all points. Bottom line is how does it feel? If the saddle is not obviously up or down at first glance, I would say you’re okay.

This last part is for men only; so ladies you can stop reading now...

If you get that burning sensation in your scrotum, it is probably because the skin is pinched between the perineum and the saddle. If you reach down in your shorts and lift your boys up clear of the saddle; a proper pair of cycling shorts will hold them in place and this usually takes care of the problem.

Ladies, if you are still reading, don’t you do anything you are told?

Sunday
May132007

I went to the edge again

[Sunrise on the pier at Folly Beach.]


Three weeks ago, I rode to the Edge of America and back. (AKA Folly Beach.)

Yesterday I set out at 7 am. and did the same ride taking the exact same route. This time I did the ride in 2 hours and 50 minutes, ten minutes faster than last time.

What a difference three weeks makes.

Thursday
May102007

Give up Lycra and my Helmet; not Bloody Likely

A British online magazine called City Cycling appears to be aimed at people commuting to work in large cities. It is encouraging that there are enough people doing this to show interest and support for such a website.

However, a recent article suggests that cyclists should abandon lycra and helmets. The author of this piece seems to think that cyclists dressed in such a style are seen as “not human” or are from another “tribe,” and consequently unworthy of attention.”

The idea is, dressed in street clothes, i.e. jeans and tee shirt or a suit and tie, other road users will see us as human beings just like them. As a result they will be a little more tolerant towards us. Somehow, I don’t think so.

If I ride down the middle of a traffic lane, take the lane so to speak, because I am attempting to turn left; the person behind me, delayed for a few seconds is not going to be any less pissed off if I look like I just stepped off the cover of GQ.

As for the idea that the driver doesn’t see me as human? He knows I’m human, otherwise he would run me down like a squirrel. I would like to think it is human decency that prevents him from doing so, but more than likely it is not wanting to deal with the consequences, that is the biggest deterrent.

In a few cases, I think it is the fact that they could run me down, but are not allowed to in a civilized society that makes them so mad. They will sit behind a farm tractor doing ten miles per hour for as long as it takes, and deal with it, but God forbid they should have to slow to fifteen or twenty miles per hour for a few seconds behind a cyclist.

When I go riding I put on my team jersey, not because I want to be seen as belonging to some other tribe; I just want to be seen, period. I choose a team jersey for its bright colors, not because I support that particular team.

The other reason I choose a genuine team jersey is the quality of the product. It is designed to give the wearer maximum comfort under extreme racing conditions. So I know during my modest exertions I can concentrate on riding my bike without being focused on how uncomfortable my clothes make me feel.

Designed to keep the wind off if it is a little chilly, or to keep me dry and comfortable if I am sweating like the proverbial pig. I can throw it in a cold wash when I’m through riding, and it is practically dry after the spin cycle.

Another quote from the article, “Normal people don't wear polystyrene hats.” Bicycle helmets don’t give total protection, and no one should be lulled into a false sense of security by wearing one.

I was wearing a helmet when I hit an SUV last December and still came away with a hairline skull fracture. But I was glad I had a little Styrofoam between my head and the very solid side of that vehicle, and I am sure without it I could have been injured more.

You don’t have to wear lycra and a helmet to enjoy cycling, and I am not advocating that everyone should dress thus. It is a sport that can give pleasure at any level. I just happen to be an ex-racing cyclist and still enjoy a road bike.

I cannot ride unless I am going balls out, as fast as I can. It is what I have done all my life; I try to maintain a level of fitness so I can continue to do so. I cannot ride in this fashion in a suit, or in blue jeans feeling like my nuts are in a tourniquet.

In spite of my earlier comments, when I’m on the road I try not to adopt an “us and them” attitude; it serves no useful purpose. Traffic is not going to get any lighter, so I must deal with it. However, I am going to exercise my right to ride on the public highway.

I try to be considerate and courteous at all times; if someone slows down and is cautious when passing, I will often give them a little thank you wave. My way of saying thank you for not passing at fifty miles an hour, missing me by inches.

Most road users don’t mind sharing the road with a cyclist if they are predictable and give clear signals of their intentions. They dislike cyclists who weave in an out of traffic for example.

If I wear lycra and a helmet at least I look like I know what I am doing. If I wear street clothes; I could be someone who just decided to “go green” the previous week, or someone who has just got their third DUI ticket.

Tuesday
May082007

Stayers

[Picture from Cycling News.]


My last article on Fork Rake and Trail brought an email with the question:

“Why does bike designed for Motor Pace Racing have the fork raked backwards. Is it to increase trail?”

The Stayer bike as it is called, has a smaller front wheel, a steeper head angle, and reverse fork; all designed to get the rider closer to the motorcycle that is pacing him. There is a roller mounted behind the pace machine, set at a regulation distance. It is up to the rider to get as close to that roller as he can for maximum drafting effect.



If you look at the drawing on the left, you can visualize that a smaller wheel means less trail, a steeper head angle also means less trail, but the reverse fork increases trail to compensate. A stayer bike may have a little more trail than the average track bike, but not an excessive amount.

Another reason to have the fork reversed is that occasionally the rider will bump the roller on the back of the motorcycle. If he does the roller will spin and the fork will flex easier in the direction it is raked or bent, thus absorbing these slight bumps.

Friday
May042007

Trail, fork rake, and a little bit of history

If you draw an imaginary line through the center of your bicycle’s steering tube (Steering Axis.) it will reach the ground at a point in front of where the wheel actually contacts the ground.

The difference between these two points is known as the trail. Trail assists steering; as you lean the bike to the left or right, the steering axis moves in that direction, and thereby turns the wheel in that direction as it pivots on the point of contact with the road.

Trail also assists the bike in holding a straight line. It works on the same principal as a castor wheel on a grocery cart, which goes in the direction it is pushed. (Or in theory it is supposed to.) This is why it is called “trail,” because the wheel trails along behind the steering axis.

Fork rake or offset is the distance between the steering axis and the wheel center. It doesn’t matter if the fork blade is curved forward in the traditional way, or if the fork blade is straight but angled forward from the crown. If the offset is the same the bike will handle the same.

You will see from the drawing above, if the head angle is made steeper then trail decreases because the steering axis moves closer to the wheel’s point of contact. Conversely, a shallow head angle will lengthen trail.

Less fork rake, increases trail, because the wheel center is moved back away from the steering axis. More fork rake means less trail because the wheel center is moved forward.


Bicycles built in the 1930s through the 1950s typically had as much as 3 ½ inches (9cm.) of fork rake resulting in very little trial, often zero. There was a theory at that time that trail made steering heavy and sluggish.

I remember writing an article for Cycling magazine in the 1970s; someone wrote to me saying my theories on trail were wrong, and sent me an early 1950s article from Cycling to prove it.

The old theory was that if you had the front wheel’s point of contact behind the steering axis, when the steering was turned 90 degrees the point of contact was then on the steering axis line. Therefore, the front end of the bike had dropped slightly, and to straighten up again, the steering had to lift the weight of the bike and rider; thus sluggish handling.


While this statement is true, in practice when riding, the front wheel never turns 90 degrees. In fact during normal cornering the front wheel turns very little, making this whole theory about the front of the bike going up and down irrelevant.

I started racing in the early 1950s and I can say from experience the bikes of that era did not handle and corner near as well as today’s designs. These bikes handled reasonably well because frames were built with much longer wheelbases, wheels and tires were heavier, and tires were fatter.

Road conditions at that time, especially in countries like Italy and France were often appalling. The long fork rake and the long wheelbase had a dampening affect on the rough road conditions.

[Typical European road conditions in the 1940s. Louison Bobet leads Gino Bartali (striped cap) and André Brulé in the 1948 Tour de France. Picture from The Wool Jersey.]

As road conditions improved, bikes were built with shorter wheelbases and at the same time tires became much narrower. It eventually became necessary to increase trail to keep the bike going straight.

There was a somewhat chicken and egg situation with regard to shortening wheelbases and adding trail. In my case I shortened the fork rake to shorten the wheelbase and found the resulting increase in trail was an improvement.

Other older established builders, still clinging to the little or no trail theory, shortened the fork rake but at the same time made the head angle steeper to maintain the trail status quo.

This made for some very squirrelly bikes being built in the 1970s, with 75 and 76 degree head angles and front wheels almost touching the down tube. Shorter chainstays to shorten the rear end of the bike were pretty much universally accepted.

A shorter wheelbase means the bike will turn on a tighter radius. Think of a school bus and a compact car, which one will turn tighter? The front wheel turns less on a short wheelbase bike on any given corner; this translates to having to lean less to get around a bend.

I think the big advantage I had was that I was still actively racing and could try out these changes, and experience the difference first hand. Eventually everyone agreed that trail was not a bad thing and head angles became sensible again.

Frames I built had around 2 ½ inches (6.3cm.) of trail. In the early 1970s I did experiment with more trail but found that the bike felt sluggish and had a tendency to wander when climbing or sprinting out of the saddle.

As with any design aspect, more is not necessarily better; for a road bike with a 73 degree head angle the optimum trail seems to be around 2 to 2 ½ inches (5 to 6.3cm.)

 

Addendum. Nov 15, 2008.

There seems to be some confusion over the term “Fork rake,” which I can understand. The dictionary definition for rake is “The angle of inclination from the vertical.” However, when referring to bicycles, rake and offset are different terms for the same thing. Both are the term for the distance the wheel center is set from the steering axis, regardless of the head angle.

 

This probably came about because early framebuilders were artisans, not scholars. To add to the confusion, a bicycle head angle is measured from the horizontal, not the vertical. Back in the day when all bicycles had perfectly level top tubes, it was the angle measured from above the top tube to an imaginary extension of the head tube.