<H1>Fixed Gears and Knee Health</H1><H3>By Charles Renner</H3><BLOCKQUOTE></BLOCKQUOTE><H2>How I came to ride a fixed gear.</H2><BLOCKQUOTE><U>Knee problems</U> (chondro-malacia patella) caused me to pretty much stop riding. This was hard. I do not like to drive and did not own a car until I was 25; this was a big hit. I bought a house 3 miles from work ? I figured that even dead I should be able to pedal that distance.

My doctor mentioned surgery but said something to the effect of "lots of people will want to operate, but if you can get along with it as it is, let it be. The surgery can only be done really well once, and the later you do it, generally, the better off you are". Two years later the house up the street was sold. I met my new neighbor, who did a several things for me that got me back on the bike. I have been able to avoid the surgery and my knees seem to be holding up well.

The first thing he did was ride with me. Turns out he used to race and coach. He felt like I still had some go in me. We did a 25-mile ride (I was in pain by the end) and told him so.

He smiled and said "Kid, come by the house next week".

1. He reset my bike to the proper size. - Handle bar location, etc. For people with knee damage, it is frequently better to have the seat a little higher than normal. This causes the maximum knee flex angle to be less, which sometimes helps.

2. Insisted that I go to <U>clipless pedals</U> and have what was called a "<U>Fit-Kit</U> " done to align the pedal <U>cleats</U> to the shoes. This was just when clipless pedals came out (late 80s). They did not have float and were very expensive. Of course, the alternative was the surgeon\'s knife; the pedals looked pretty cheap in that context. The idea behind cleat to shoe alignment is to have your foot / leg / hip in their natural position when on the bike. My right foot is pronated, so that is normal for me? The Fit-Kit was one method to measure this alignment. This was critically important when <U>SPD pedals</U> first came out because they had no float. Today, it is probably not as critical, as most clipless pedals have a lot of float, with the speedplay having the most.

After properly fitting me to my bike / pedals, my neighbor looked at me and smiled. "Kid, come by the house next week".

The next week he had two identical mountain bikes. He said let\'s race. I looked at him like he was crazy. My knees hurt, but I was 10 years younger and in better shape.

He insisted, I agreed, and then he laid down the rules: Put the bike in the lowest gear and leave it there. You are not to shift gears. Good luck.

It was only a short climb, but he knew I did not have chance. He was waiting for me at the top of the hill. Blew past me doing all of 5 mph. I have never seen anyone spin the pedals as fast as this guy.

He waited for me to catch my breath. He certainly was not breathing hard. "Look kid - if you want to win, you got to spin. Come by the house next week".

The next week he put on his <U>fixed gear</U> to teach me how to spin. To learn how to spin, a fixed gear bike is usually used. Almost all serious bicycle racers spend some time on a fixed gear. A fixed gear is like a track bike, no gears, no freewheel (no coasting - ever!!), no brakes, and paid up life insurance policy. The biggest difference between a fixed gear bike and a track bike is the gear ratios. Most track bikes are in the 52/13 range. They are built for pure speed. Fixed gears for street use are generally much lower. I am running 38/18 on mine (moving to 42/17). This is a low enough gear to keep from putting too much pressure on the bearing surfaces of the knees when starting off from a stoplight and for maintaining control going downhill. The other difference is most people put a front brake on them for emergency use. I have one on mine.

<BLOCKQUOTE>(That\'s a VERY low gear for fixed-gear use! --Sheldon Brown) </BLOCKQUOTE>My neighbor had researched bike knee injuries, and found that they were never noted until the <U>safety bike</U> emerged. The safety bike was the first bike that coasted and that had both the front and rear wheels the same size. The ordinary bikes of the time, "<U>Penny-Farthngs</U>" (large front tire, small back tire) had a direct drive, like a tricycle. You used your legs to stop the pedals from turning. It can be done. It is HARD at first. His theory was that this built up the opposite muscles around the knee, and that it was muscles that help hold the knee (patella) in proper alignment. My physical therapist friends have mentioned that the idea is plausible. Some runners will run backwards to try and accomplish the same thing.

You can read about <U>spinning</U> , but I\'ll give a quick mechanical example:

Light turns green. Rider A is in his highest gear. He VERY slows mash down on the pedals trying to get the bike to move. Every pound of force pushed down on the pedal is going through the bearing surfaces of his knee. That is a lot of unnecessary stress on the knee. This is what caused my knee problems in the first place.

Contrast: Light turns green. Rider B is in his lowest gear. He VERY easily spins the pedals - the pedals are moving fast, but the FORCE on the pedal is LOW. The force through his knee is LOW. He shifts the gears as he picks up speed. Rider A is way behind him.

I see this everyday - people standing up and mashing down on the pedals. You\'ll do this a little with a fixed gear too (can\'t shift) but you\'ll learn to start easy. You do not start your car off in 5th gear. You start in 1st and then shift. They put a transmission in cars for reason. If you shift too early, you\'ll actually hurt your engine. Given a choice between two gears to go up a hill, you\'ll get better gas mileage and longer engine life in the lower gear. The same is true for your knees on a bike. People get macho and say they are not going to shift going up a hill. Not a great idea in terms of how long it will take to get to the top of the hill or the stress that will be put on the knee. If you got\'em (gears), use them. If you don\'t, then you are on a fixed gear and hoefully you have the gearing set to your ability.

To read more about fixed gear bicycles:

<BLOCKQUOTE><U>http://sheldonbrown.com/harris/fixed.html</U> </BLOCKQUOTE>

Particularly:

<BLOCKQUOTE><U>http://sheldonbrown.com/fixed.html</U> </BLOCKQUOTE>

</BLOCKQUOTE><H2>A few warnings:</H2><UL><LI>Make sure your feet are firmly attached to the pedals!!! If your foot falls off, the pedal will come around and hit the back of your ankle. Not good.

- No shoe laces and no loose clothing. If ANYTHING gets caught in the chain, you will most likely pedal your head into the pavement. Frequently fatal. It is almost guaranteed that you will go down. I have never had it happen. Helmets anyone?

<LI>Pedal strike on the corners. I have found this not to be a big deal, but courtesy of rollers I have scary good balance. For someone not used to it, hitting the pedal can be pretty disconcerting. Shorter crank arms are probably a good idea ? they give more pedal to road clearance and they are a better for spinning.

</LI></UL><BLOCKQUOTE>Most people find that running is more physically demanding than bike riding. I agree, until you get on a fixed gear bike. On a fixed gear bike, you pedal up the hill, and work hard. You have no choice. On the downhill, you don\'t get to relax at all. You are still working. It is pretty brutal. Start out on flat land and do some slow upper and downers (speed up slowly, slow down slowly, without using the brake). Go slowly or you are very likely to be sore the next day.

Spinning is good fun, and it is what has allowed me to return to cycling to the point where I can pedal thousands of miles with ~50 pounds of gear on the bike. My knees take the load up and down the mountains without complaint thanks to my neighbor and the things that he did for me.

-- Charles Renner Folsom, Ca.

"Hey, kid, come by the house next week. We?ll work on your balance. Ever been on rollers?"




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