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Problem Scenario
I bike a lot and have wondered which gear was the best to bike in if you could only use one gear.

Broad Question
What gear is the most efficient on a bike?

Specific Question
Does the gear on a bike effect the rider's efficiency?

Hypothesis
It is hypothesized that gear 5 will be the most efficient.

Graph of Hypothesis
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Independent Variable:
Bike Gear

Dependent Variable:
Efficiency (Heart Rate and Time)

Variables That Need To Be Controlled:
Rest time, place of experimenting, and the bike used

Vocabulary List That Needs Explanation
Efficiency, accomplishment of or ability to accomplish a job with a minimum expenditure of time and effort. Abstract, a summary of text, scientific article, document, speech, etc. Derailleur, a gear-shifting mechanism on a bicycle that shifts the drive chain from one sprocket to another.

General Plan
I'll set up my bike on a trainer, the rider will where a heart rate monitor. Then I will bike a certain distance on the trainer. I will have 4 riders bike the distance on each of the nine gears. Then I will compare average heart rate and time of lap.

Potential Problems And Solutions
The derailleur breaks; bring a multi-tool.

Safety Or Environmental Concerns
Falling off the bike

Experimental Design
(add the correct headings from the experimental design page before beginning)

Resources and Budget Table
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Data Table
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Time Line
End of March: Done with Experimenting April Break: Done with typing up conclusions Early May: Done with putting the poster together

Background Research
There are many things that can effect how efficient a rider rides. Their heart rate plays an important part, the lower heart rate the better. The techniques you use when you ride can have an effect as well. Gearing on a bicycle has a lot to do with how hard you pedal. Many things go into how you ride.

Heart rate is different for everyone. Many things can effect a person's heart rate; one is your age. You have a faster heart rate when you are younger because your body is growing. If you are an athlete your heart rate is slower because your heart is stronger. The stronger your heart is the less it has to work in physical activity, making it more **efficient**.

Exercise physiologists identify and analyze your form when you do a physical activity. They attach sensors to you so they can analyze the way you ride a bike for example. Then they can explain to you how to ride a bike more **efficiently**. Many professional cyclists do so they can ride as efficiently as possible in long races like the Tour de France.

Bicycle gearing is the speed the rider's legs turn compared to how fast the wheel turns. Older bikes have one gear where as modern bikes have gears that change in the front and back of the bike. These are called multi-speed bicycles. Multi-speed bicycles allow you to ride more comfortably and **efficiently**. The more teeth on a gear the less force you have to put out to make the wheel turn. Less teeth means that you have to put out more force.

All of these things can have an effect. If you want to ride more efficiently you should try to get a lower heart rate. You should also figure out the optimal way to ride a bike. Lastly, and one of the most important things is to ride in the right gear. How efficiently you ride a bike can mean the difference from winning and losing a race.

Detailed Procedure
1. Make sure tires are full of air 2. Hook bike computer sensors to back wheel 3. Attach back wheel of bike to the trainer so you don't go any where 4. Have rider 1 put on heart rate monitor 5. Put bike in gear 1 6. Rider 1 rides for 3/4 a mile on trainer 7. Write down average heart rate and time of lap for that gear 8. Reset bike computer 9. Wait for rider to return to a resting heart rate 10. Repeat steps 5-8 for gears 2-9 11. Repeat steps 5-9 for riders 2-4

All Raw Data
See data table above

Graphs


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Data Analysis
The results show that gear 9 had the lowest amount of heart beats and as the gear got lower the amount of heart beats increased making it less efficient. The time of laps significantly decreased as the gear increased. Gear 1 averaged over 6 minutes in time of lap and gear 9 was under 3 minutes. The average heart rate had a little increase as the gear increased. Gear 1 was just under 140 bpm and gear 9 was just under 160 bpm.

Conclusion
The most efficient gear on a 9 speed bike is gear number 9, because it had the least number of heart beats. The least efficient is gear 1, because it had the most heart beats. This rejects my hypothesis which predicts gear 5 to be the most efficient.

Discussion
As the gear increases the number of heart beats decreases. The less amount of heart beats the laps takes the more efficient it is. There is a very strong relationship between the gear and the time of laps. The r squared value is 0.9247 because the points are very close to the line of best fit. The gear and average heart rate have a less of a relationship than the gear and time of laps. The r squared value is 0.6267 because the points are more spread out than on the Time of Laps graph. The relationship between the gear and efficiency is very strong. It is a bar graph so there is no r squared value, but as the gear increases the total number of heat beats decreases. Which makes gear 9 the most efficient. I was able to answer my question; the gear does affect the rider's efficiency. My hypothesis was off. I predicted gear 5 to be the most efficient, when the answer was actually gear 9. There could be potential flaws in my data because the rider's could have exercised earlier in the day before they did the experiment or they could have tried harder on some gears. This data could be helpful to bike riders. If you were at a bike race and your derailleur broke you may have to choose which gear you ride on and change to that gear by hand. You'd have to know which gear is the most efficient to ride on, if you choose gear 3 your time would be effected. I could improve upon this by finding a way to tilt the trainer so there would be inclines and declines. A future question may be, does wheel size effect the speed at which you can ride? Bike riders will have an easier time riding if they know which gear they should ride in.

Benefit to Community and/or Science
This data could be helpful to bike riders. If you were at a bike race and your derailleur broke you may have to choose which gear you ride on and change to that gear by hand. You'd have to know which gear is the most efficient to ride on, if you choose gear 3 your time would be effected. This could help professional cyclists with races when they are on flat ground. They would want to go as fast as possible without exerting too much energy. Regular people may just want to know if they were to go out and ride. You would know which gear to ride in whether you wanted to be efficient or just cruise along.

Abstract
My specific question was does the gear on a bike affect the rider's efficiency? I hypothesized that gear 5 would be the most efficient. The background research showed how exercise physiologist have been analyzing the way people ride bikes to help them ride more efficiently. Each rider wore a heart rate monitor, the bike was attached to a trainer. They had to ride 3/4 of a mile in each gear. As the gear increased the efficiency (total number of heart beats) decreased. The most efficient gear on a 9 speed bike is gear 9. The least efficient is gear 1. This data could be helpful to bike riders. If you were at a bike race and your derailleur broke you may have to choose which gear you ride on and change to that gear by hand. You'd have to know which gear is the most efficient to ride on if you choose gear 3 your time would be effected.