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Discussion Starter · #21 · (Edited)
Attempt #2

24:55 with a camelback loaded with a lead weight and some water to get to 165 pounds exactly. That's -1.11% (in seconds) off my Trial #0 time. I'd call that a dead heat. It's 4.9% slower than Trial #1.

The segment times on Strava show that I had a consistently slower pace up the climb. until the last segment where I tied my Attempt #0 time.

The sensations I had were that I had much more fatigue in the last 3+ minutes of the climb and I thought I was going slower. The bottom 2/3's of the climb I felt I was going to set a good time regardless of the extra weight.

Very interesting that I felt like I could ride a bigger gear just fine on everything but the last 3 minutes, and yet was going slower.

No unusual wind conditions. Trail was slightly damp. I don't ride it any differently when it is dry, which is most of the year.

http://www.analyticcycling.com/ForcesLessWeight_Page.html suggests that I would have been 21.67 seconds faster without the extra 5 lbs.
 

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Discussion Starter · #22 ·
at 5 pounds loss dont think youve lost anything this could easily be water weight
That's a half-gallon of water! (1.89... Liters)

Look at it another way, my weight would fluctuate +/- several pounds if it were water weight. It doesn't. Maybe I'm unique, but I don't think so.
 

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Discussion Starter · #23 · (Edited)
Adding weight that isnt body mass wont have an affect on power output. Therefore its obvious that carrying 5 extra pounds will slow you down.
You are missing the point. There is no question Watts figures into a performance. XC racing is not a dynamometer test. So, the test is designed like a part of an XC race, the hill climb.
 

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Discussion Starter · #25 ·
Someone could collect the data, perform statistical analysis, develop confidence intervals, and all that good stuff. And when he is done, it will be almost as good as what WR304 posted.
Thank you Bill!

The testing will provide some validation for the analytic cycling formula. Especially if more than one person contributed data using my procedure.

The goal being to get a better sense of the role gross weight plays on performance over a set course INCLUDING increased performance through the training effect.

I want to find out if it's good enough science More participants would help answer that question.
 

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Discussion Starter · #27 ·
Attempt #3

Attempt #3 Time 25:09 Weight 165 lbs. (mountain bike) Within 1% of my other 165 lb. ride time.

I'm throwing a wrench into the works here because I used my *much* heavier full suspension mountain bike. I weighed things out and loaded enough water to get to 165 lbs. cranks are 2.5mm longer on the mountain bike.

On the way up I felt I was riding faster. I think some of it is I have lower gears available and used them to suffer less, but go slower.

Weather was not a factor.

Still, super-close to my other 165 lb. ride time. Next test will be done on my 'cross bike. I've lost a little more weight too, so I'll use water to get to 160 lbs.
 

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XCdude
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San diego has many

Where do you find a hill that takes you freakin' 30 minutes to climb??? : p
I have one by my house that it takes at least 1 hour if you are in shape. 6 miles and 3000 feet.:thumbsup:
 

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or, you can just look at the fastest cyclists in the world. all of the ones who race outside tend to range from skinny to really skinny. its not scientific, but i doubt its coincidence.
I agree, during peak season, all road, XC, CX riders have about 3-6% body fat. I don't know any non-athletes who have such low % naturally.
 

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Maybe we could design a randomized control trial and aggregate our results determine if changes in body+bike weight significantly affect the amount of time it takes to complete a particular climb. If we really want to answer this question with any statistical power, we would probably need >16 or so subjects who would each do the following.

1. I create a randomized list detailing the order in which each climb would be completed
2. Each subject completes 4 time-trial climbs (unobstructed climb of your choice ~ 10 min in length that you can complete @ a speed of ~8-15 mph) under the following conditions (randomized). Do not train within 48 hours of test. Record body weight and bike weight.
a. Control 1 (no added weight)
b. Control 2 (no added weight)
c. Additional 15 lb weight
d. Additional 15 lb weight
3. Repeat test using same order of conditions to which you were randomized approximately 48 hours - 7 days later. Resume moderate training between first and second tests, but do not train within 48 hours of second test, and make no modifications to bike. Ensure same tire pressure during first and second testing sessions.

There are other factors to possibly control (weather, stress, etc). If we could eliminate all other confounders, then we might be able to answer "how much variability exists from test-to-test within a testing session (i.e. how similar are times for control 1 and control 2)?", "How reliable is this method at measuring the amount of time it takes to complete a controlled climb (i.e. is the avg of control 1 and 2 on testing session 1 equal to the average of control 1 and 2 on testing session 2)?", and finally "what is the effect of weight loss, or addition, on the length of time it takes to complete a controlled climb"?

anyone interested? as you might guess, I'm a nerd, and I conduct research for a living.
 

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Discussion Starter · #33 ·
Maybe we could design a randomized control trial and aggregate our results determine if changes in body+bike weight significantly affect the amount of time it takes to complete a particular climb.
This is great! Far better than my hack at it. I'll modify the first post and make it reflect your suggestions. Anyone that wants to can then just add their trial information.
 

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At the bottom is the randomization list, and immediately below is the legend.

1 = control trial 1
2 = control trial 2
3 = weighted trial 1
4 = weighted trial 2

If you decide to participate, reply to the thread telling everyone which letter (i.e. randomization) you are, so that each subsequent participant can select the next letter on the list. We don't want to further bias this study by letting people select their own random order in which they complete the time trials. Post the following results if/when you complete both testing sessions.

Age
Sex
Body Weight
Bike Weight
trial # (1,2,3,4) + time taken to complete the climb
method you used to add 15 lb weight (e.g. backpack, pannier, got really fat really quickly, etc)
any additional info you believe is relevant

I'll aggregate the results and run the stats to evaluate our results (descriptive stats, (3,1) ICCs, paired t-tests, and the like).

a: 2, 4, 1, 3
b:1, 4, 2, 3
c: 3, 2, 1, 4
d: 2, 4, 1, 3
e: 2, 1, 4, 3
f: 2, 3, 1, 4
g: 4, 2, 1, 3
h: 2, 4, 3, 1
i: 3, 4, 1, 2
j: 2, 3, 1, 4
k: 4, 1, 2, 3
l: 4, 2, 3, 1
m: 3, 4, 2, 1
n: 4, 3, 1, 2
o: 2, 1, 3, 4
p: 2, 4, 1, 3
q: 2, 1, 3, 4
r: 2, 1, 3, 4
s: 1, 3, 4, 2
t: 4, 1, 3, 2
 

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Discussion Starter · #35 · (Edited)
Attempt #4

This time on the same bike as most of the other attempts. I've lost some more weight, so I added weight to get body weight back to 160lbs.

My riding volume has gone up slightly to about 3 hours with gym time declining.

I set a personal best on the first 20 minutes of the climb knocking 30 seconds off my old time. But faded badly in the last 3 minutes giving all of it up. I felt the sensations go away.... Grrrr!

Still looking for more volunteers! Help us find out if it's possible to isolate the effect of weight gain/loss in mountain biking.
 

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mnoutain bkie rdier
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At the bottom is the randomization list, and immediately below is the legend.

1 = control trial 1
2 = control trial 2
3 = weighted trial 1
4 = weighted trial 2

If you decide to participate, reply to the thread telling everyone which letter (i.e. randomization) you are, so that each subsequent participant can select the next letter on the list. We don't want to further bias this study by letting people select their own random order in which they complete the time trials. Post the following results if/when you complete both testing sessions.

Age
Sex
Body Weight
Bike Weight
trial # (1,2,3,4) + time taken to complete the climb
method you used to add 15 lb weight (e.g. backpack, pannier, got really fat really quickly, etc)
any additional info you believe is relevant

I'll aggregate the results and run the stats to evaluate our results (descriptive stats, (3,1) ICCs, paired t-tests, and the like).

a: 2, 4, 1, 3
b:1, 4, 2, 3
c: 3, 2, 1, 4
d: 2, 4, 1, 3
e: 2, 1, 4, 3
f: 2, 3, 1, 4
g: 4, 2, 1, 3
h: 2, 4, 3, 1
i: 3, 4, 1, 2
j: 2, 3, 1, 4
k: 4, 1, 2, 3
l: 4, 2, 3, 1
m: 3, 4, 2, 1
n: 4, 3, 1, 2
o: 2, 1, 3, 4
p: 2, 4, 1, 3
q: 2, 1, 3, 4
r: 2, 1, 3, 4
s: 1, 3, 4, 2
t: 4, 1, 3, 2
I feel like I am back in college. Make it go away! Make it stop...haha. Nice work so far:p
 

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Discussion Starter · #37 · (Edited)
Attempt #5: End of Trial Ver 0.5

I did the climb about how I *thought* last week should go. I did the whole climb in 23:35. I was slower on the bottom segments by 10 seconds. Some of this was due to traffic. But made it all up and more on the last 1/4.

This effort had some fundamental problems.

-Gusty wind and significant heat on the top half of the climb. Nothing special about the wind, but when it gusted, it was pretty much a headwind. Both conditions were not present in the other efforts.

-It hasn't been 7 days since the last trial. The *slight* improvements are too small for attempting to capture the training effect and weight combination.

This is going to be my last attempt for a good while. The SoCal heat is coming and my schedule does not permit early rides.

-The heat brings out the casual users and one broke up my rhythm today. Why they come out when it is much warmer and thus harder is the subject for another thread.

While I put in a 100% effort, I am ready to do other rides with the little ride time I have.

I'm going to look at the results and think about what they say about weight loss/gain in another post.
 

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Sorry to hear about those annoying setbacks. It does bring up an interesting point though. While the addition or subtraction of weight to the rider or the bike (in weight gain/loss or heavy bike components vs light components) might have a small influence on the time it takes to complete a climb, other factors like wind, temp, and other riders probably cause more variance in one's climb time than the addition or loss of weight. For a mountain biker who's looking to shave a few minutes off of his or her race time is probably better off getting to the single track first, or picking good lines, or running the proper tire and pressure than trying to lose a couple of pounds in bike weight.
 

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Discussion Starter · #39 · (Edited)
Conclusions

For a mountain biker who's looking to shave a few minutes off of his or her race time is probably better off getting to the single track first.
Agreed. The fundamental thing to getting into a better selection for the first course feature that creates the funnel is power. I think we agree that descending skill is the other factor that would most affect one's finishing rank. Neither one is related to gram shaving!

If I assume races usually finish with clusters of riders. ex. First group, gap of 1 minute or more, Second group, another gap, third group. The best losing a kilo (not grams) does is slightly alter your place in your cluster.

My trials suggest most rider resources should be spent developing power instead of investing in gram shaving. As a consequence one could spend $2000 on a bike and be race-ready. ex. JHK would blow by me on a $2000 bike as quickly as he would on his mega-bucks bike.

Comments welcome...

I'm going to do the test again using your test method later this year once the worst of the SoCal heat is over. Thanks for your help.
 

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OK,
So the moral to the story is......................

Fat ain't Fast.
 
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