Crank length from the cyclist perspective

I always find cycling analysis interesting. It doesn't matter if it's equipment, training, bike fit or anything else. It's most important to review the information and determine the perspective of the author. Take the information and dissect it so that you can gain a better understanding of the information on the surface but also consider it at a deeper level.

Every article or opinion has some sort of context. Often times, it focuses on a vary narrow aspect of the sport. You need to determine if the information is applicable to your riding style or interest. Also, you need to assess if the information has an equipment focus or rider focus. For example, the latest greatest aero frame may have the greatest technology. It may be bulletproof and invisible! But, if you can't fit on it, it's useless to you.

I just wanted to get this across before I start this entry. I'll let you know my perspective. This article is written with a focus on the athlete. It is not written from a perspective of a specific aspect of cycling. With this in mind, I think everything should be written with the athlete as the primary focus. Without a functional, effective athlete, a bicycle only leans against a wall.

It's my goal to turn bicycle riders into cyclists. Happy cyclists! For the athlete, crank length needs to be the same, regardless of the type of cycling that is occurring. Every bike you own should have the same crank length. Determining the right length is a factor of fit first and then passion. For example, if you are a track cyclist, your crank will be shorter due to the nature of the event. It will probably be shorter than your road crank if you didn't ride on the track. This crank length should be translated to your road, TT and MTB.

Why? As a cyclist, pedaling is about establishing a finely tuned series of muscle contractions that turn the cranks in a circle. The size of that circle is dependent on the length of the crank arm. If you have the same crank length of every bike, your brain is able to finely tune the movement pattern associated with one size circle. If you have multiple crank lengths, your brain needs to establish multiple movement patterns. If you are talented and have an excellent sense of movement, this will have a limited but real impact on you. If you have a limited ability to understand where your joints are in space and the speed/direction they are moving, having multiple cranks lengths can be a source of injury. Think about it from the brain's perspective.

Taken in perspective to event. I could quite possibly have three different crank lengths. Additionally, there's probably an "event based" piece of research to support each length. I could have 170's on my track bike. I'm 5'10". My track cranks might be shorter. (I'm not a track cyclist). My road bike could be 172.5's based on calculations or manufacturer suggestion. If I go MTB or Tri, I could be looking at 175's. From the brain's perspective, this is the equivalent of putting an efficient motor pattern in a blender.

Give your brain a chance to become great at one size circle. Purchase the same crank length for each of your bikes.

Does bike fit change?

Absolutely. Your fit on the bike is going to change for one of the following reasons. Your equipment has changed or you have changed.

Pedals, shoes and saddles all have a significant impact on fit. The pedal/shoe combination impacts how close your foot is to the pedal spindle. The saddle impacts the distance to the bottom bracket based on the thickness and shape. Saddles also impact your fore and aft position related to the bottom bracket based on where you sit on it for maximum comfort. Cranks change everything from the pedals to the saddle. Changes in frames impact seat angle, head tube length and head tube angle. Changing the handlebars impacts reach to the hoods and the depth of your reach to the drops. Handlebar rotation and hood position impact wrist position. Basically, you can change tires, tubes, chains, brakes, derailleurs and cables without impacting fit. Everything else causes a change.

What about you. Here's the list. Increased or decreased weight; increased or decreased flexibility; Injury or degenerative changes. If you put on a few pounds over the holidays, you will note that you can't get into the drops as easily. An adjustment should be made so that you can continually utilize all the handlebar positions. Injuries also impact fit based on your tolerance to assume various positions.

Ultimately, you want to monitor fit so that pedaling efficiency remains relatively unchanged. Just a few millimeters here or there can put you in a position of reduced efficiency. Any time something changs that impacts you ability to drive the pedals, you need to get your bike fit checked out.

Mind excavation

The statement, "It's just like riding a bike" comes to mind. Cycling is such an automatic task that, once learned, doesn't require much additional training if you haven't ridden in a long time. You just jump back on the bike and start riding. However, what if the task was originally learned poorly or with an ineffective motor plan, now we have to do some mind excavation.

It's my job to take a task that is seemly very simple and automatic, bring to a conscious level of awareness, re-train it so that it's more efficient and then process it to the point that it is automatic again.

The process of making cycling a cognitive or conscious activity is actually very simple. I use software such as Computrainer Spinscan, video analysis (Dartfish) and rollers. This equipment quickly makes riding a bike a conscious experience.

The process of re-training is not always as easy. This is dependent on the riders ability to assimilate the information and make changes in the way they move. Each rider is unique in the type of information they need to make effective changes. Sources of stimulation include visual, auditory, vestibular and tactile(or seeing, hearing, balancing and touch)

Returning improved motor patterns to automatic requires repetition, repetition, repetition of the correct pattern.

Finally I can test how automatic a motor patter is by making cognitive challenges or ask questions that require the brain to process information. If the newly learned motor task is automatic, the brain is able to process information. If the motor task is not completely automatic, one of two things happens, the motor activity looses quality while the brain processes the information or, the brain is not able to process the information correctly. This occurs because the rider is using conscious thought to process the motor task.

Starting out right

I have the wonderful opportunity of training my wife and oldest daughter. What a great experience because neither has ridding significantly other than putzing around the neighborhood.

They are like blank slates. We are starting out with our focus on good fit followed by good mechanics. My daughter immediately took to the computrainer spin scan module. I'm always amazed by kids ability to interpret video data and assimilate it into function. I didn't have to explain anything about the spinscan graph. I just told her to make the line as flat as possible.

She started pedaling and experimenting with the way she pedaled the bike. You could see her brain working as the video display changed, she would make small corrections to reach the goal that I gave her. Pretty soon, her spinscan was 80. If you don't know anything about spinscan, that's a pretty good score.

My wife is focusing her efforts on learning the rollers. We are working on specific drills that make her pedal correctly.

Ultimately, it's all about creating movement and assessing if the movement is beneficial or not. Your brain creates a "database" and learns to move in better and more effective ways.

Dartfish proves valuable immediately

Last night, I was working with one of my longstanding clients. She has made incredible gains over the course of training but there's always been a few little technique issues that continue to be a problem.

We took a few segments of video and began to dissect her pedal stroke. Within a minute, I saw a problem. Dartfish allows the user to look at video frame by frame. It also has the capability to analyze angles.

We identified the problem and then we began to correct it immediately. Within a few minutes, her technique was better. Followup Dartfish video clips proved that she was changing her technique and it was making a positive change.

Permanent changes takes thousands of repetitions. It will take several rides before this problem is totally corrected. However, within the lab setting, we were able to identify the problem, teach correct technique and she was able to perceive what good technique is suppose to feel like. Amazing stuff.

Dartfish is a reality

Dartfish is a premier video management software suite. It has the ability to import, analyze and compare video. Go to www.dartfish.com to take a look.

With Dartfish, I have the ability to stop or slow video and use that information to educate and train riders to improve technique.

Video will be incorporated into almost every session. For bike fit, I will take before and after clips. Primarily it will be used to teach pedaling technique. Sometimes, it's difficult for a rider to understand how their body is moving on the bike. Video capture makes it very clear.

I look forward to serving each of you with this technology.