Thursday, June 18, 2009

Modern equipment and Net Thrust!

Perhaps we should call fitting "Speed Fix".  What speed do you wish to go?

With modern equipment, a difference in speed can be as much as 5 mph.  But don't forget, speed principally depends on athletic ability and your body & your understanding shape &  forces.

We just spoke with MD Steve Smith who's wife Kristin Smith just won her race, plus put abouttime (30 min.) into her rivals in the Boise Ironman 70.3.  We have worked with Kristin on her body potential on the bike.  She is some what muscled, yet a very good endurance athlete.

When we did the fit for her, we had only one real option to make her faster, that was her buying some aero bars that cost her $1,300 bucks.  Most people would not do this, but she wanted to go faster.  The bars where the only bars on the market that would allow us to put her body in the correct shape.  We also got her to buy a good helmet, allowing her more mph!  The rest is history!

She learned she has an downhill advantage, can make more mph on the flats, keep pace on the false flats, plus how to not to loose the distance and maintain that pace on the uphill.  It's her open mind to learn, plus the many years of having misleading info presented to her by coaches that allows her to kick butt!  Most people don't care, don't know,  and they can be sold anything i.e any fit, any idea?  Marketing!  Training can help you apply more power, but if you don't know how? 

Truth is, an average healthy adult can make the watts to move along, and almost any bike setup and at any age.  Just note the folks on the low rider bikes, town bikes, etc...   Put them on a hill and game over!  Gravity kicks and the weight of the bike & body is a factor.

It is hard to say what is the optimum weight, as we come in many shapes & sizes.  We have seen that through the many years of working with all types of bodies, and we have about 30 different body types winning the biggest races in the world we can all learn where we can level the field. The range can be from 115 lb to over 200 lbs for some of the fastest guys & gals on a bike.

Common sense, points out short-term anaerobic exercise uses energy stores in muscle more than a steady state, due in part of the slower metabolism that so many are trying to find your best cycling profile.  What's wrong with this profile?

The real problem is that steady state is more the most part a myth!  In the outside world, not on a track, the amount of oxygen you can absorb in the blood and then convert to working energy is always going to change.  Yes, you can improve your capacity to absorb O2 by training. The muscles that aid in breathing need to be trained and that makes a difference up to 25% or more? That depends on the time and the focus of the person towards training.  Few find the time or care, they just want to go for a ride!  Most people have a job, so they can't pick the best time of day i.e. temps to go train!

If a person doesn't have to work for a living, has a sugar daddy or sugar mommy, they have a very real chance of being a pro.  It's mostly about time and learning what you can and can't do with your body type.

Many of the folks just want to use the game as a way for weight reduction, be social,  and to burn the calories they get from their beer or wine (about 800 calories per hour).  The rate of calories per mile are constant until you start more wind resistance that comes from more speed.  So if you want to look cool,  have your own club, have a cool kit you can have about any fit as most clubs have the no drop rule. But if you want to burn more for the buck, don't use no drop club rules with cycling, go walking!

What does this mean?  YOU BURN MORE ENERGY GOING FASTER!  Most people prefer to ride more slowly, talk, so they have to compensate by going longer distances (more time), but understand that means more wear and tear on the body and maybe your mind hearing all the gossip!  

Perhaps, it's better to understand you have more pressure on your body parts i.e. saddles, hoods, feet, etc... where they interface with the tool of choice. Again, if you want to burn more energy, don't cycle, go walking (esp. uphill) or running, a bike is only about 1/3 the need of energy for the same distance.  

Another myth, you will also hear that a round tube in the wind doesn't change the drag coefficient?  Who is selling you this?  A round tube takes 10 times the energy to move through the air.  Round tubes work great for mtb, but not so for higher speed, but if you go slow say about 15 to 19 mph, who cares. Flat faces, sharp edges are even worse!  More than round tubes!  
Air turbulence outweighs the benefits for saving weight, even all day! So you smart guys out there, putting holes to save weight is only going to cause more drag!  As in much of the industry, it comes down to production cost of x, y, z and who is willing to to make the shapes and to take it to market!  The industry retards what we can do more than you know!  Very Sad!

Much of the friction drag is caused by (viscous shear) or by the the layer of air that is moving parallel to a surface.  Polished surfaces work better than rough!  Then you have pressure drag i.e. high vs. low.  At higher bike speed, pressure drag is much higher than the polished surface drag, so if you go faster, a streamline bike, wheel, etc... is most effective.  So pick you frame and parts with that in mind!  Again, what is it you intend on doing (slow climbing, fast speeds, etc...)

So what's up with a lower racing position?  If you want to go faster,  you burn more energy, you have to be able to make more power to over come the higher wind resistance that comes from pressure drag.  So why would you set the bike up for going faster, only to not  i.e. the many fitting ideas that want to sit you up more?  Myth!

So you want to use energy to control your weight and you want to use a bike to do so? Remember a bike requires more time to use the k-calories if you only intend to poke along!
Forces (aerodynamics, gravity, tires, bearing frictions, chain tension, inertial "accelerating/decelerating", braking  slow speeds) do retard your thrust that comes from the rear wheel, but also the front tire when you i.e. go uphill below 8 mph! 

On the other hand, if you are more muscular and more times than not, you are then are more compact, or your bike is more compact you need less power.  You can see this with some of the tri guys & gals and the way they have their bikes setup.  It is common knowledge that speeds over 25 mph, wind resistance is over 90% the retarding force.  Now think about how many don't check their tires, the tire contact patch, rolling resistance with velocity makes a difference in your velocity tailwind or headwind.

The direct function of muscle mass and its cross-section produces power.  So when you pull up next to someone, get in race mode, and think you are the king or queen of endurance, all the time you are sizing up your rival with the compact body type like "toad", be aware on the flats that well-conditioned (with the cardiovascular conditioning) "toad" can make more power output in which leads to a higher mph i.e. sprinter, and they might be able to hit 40 mph for over 200 to 300 meters. They might even have the correct tire psi (high pressure) that lowers the drag that comes from dynamic friction.  They might even have dish, in which reduces the egg beater effect i.e. rotational air drag of the wheel, also a function of velocity.  This is true even when the rear wheel is in a stationary bicycle trainer.  

Now let's look at a lighter cyclists, who will always have an advantage climbing hills as slopes change.  So I think it is safe to say, the game is all about the rider knowing what the net thrust is to the rear wheel after losses through the many forces.

The front wheel doesn't provide net thrust, but it can slow you down!  You can streamline forces by choosing shapes that move through the air more efficiently i.e. fish!  

So maybe that is why you don't see the full dish wheel on the front?  Should a wind come up, it would be hard to control the bike.  So if you do use a streamline to move through the air more efficiently, you might want to get your brain on what that rear wheel is doing in the wind. Ha!

No comments: