Sorry for the lack of posts, but I've been out of town. At the end of May I retired from teaching physics at the University of Wisconsin-Manitowoc. Then my wife and I went to Texas to pick up our travel trailer which we had left there in January. We took our time returing, stopping in Tulsa, Oklahoma for two weeks. Tulsa has a great bike trail system along the Arkansas river called the River Parks trail system. The trail is blacktop and is about 30 miles in length. Parts of it have separate paths for walkers and bikers.
One of the neatest things is that the trail goes past Turkey Mountain which has some of the best technical singletrack in Oklahoma. Probably a good 15-20 miles of trail. We always stay at Cherry Creek Mobile Home Park which has spots for RV's. The River Parks system passes right by the trailer park and Turkey Mountain is just 2 miles down the trail. You can't get better than that.
I tried some singlespeeding at Turkey Mountain but just didn't have the gearing. The trails are very technical, lots of rocks, and for me slow, so I went back to the 1x9 setup. I tried a 34x19 but that was just too tall. For me I think a 32x20 would work but didn't have one.
Now I'm back in Wisconsin. Two days ago I went to the Northern Kettles and rode with the 1x9 setup. I plan on going back tomorrow with that setup again then switch to a singlespeed setup this weekend. I want to get some base data as a 1x9 then compare performance to the singlespeed. I think at the Kettles the singlespeed will be faster.
Mike
Thursday, June 16, 2011
Monday, May 16, 2011
Single Speed vs Derailleur Friction
Today I did an experiment to measure just how much additional friction is in a Derailleur as opposed to a single speed setup. An easy test shows that the derailleur has more friction. Take the pedals and spin them backwards in each setup. What you will find is that when connected to a derailleur the pedals stop quickly. In my case in about 1/2 a turn. Whereas in the single speed setup the pedals move easily, in my case more one turn.
I wanted a more quantitative measure of the difference than just the above observation. So I attached a weight to the pedals and measured the amount of weight needed to take the pedals from horizontal to vertical in 1/2 a second. What I found was that the derailleur took 4 times as much weight. This means that the power output needed to just turn the pedals is 4 times more for the derailleur than in the single speed setup.
Next I tried to determine the actual power needed. This was a very crude estimate but I came up with 16 Watts for the derailleur verses 4 Watts for the single speed. The difference of 12 Watts is power that is not going to moving the bike but is needed to just overcome drive train friction.
At the Iola race an additional 12 Watts of power for me would have translated to reducing my race time by two and a half minutes. That would have moved me from fifth to third in my age group.
All these measurements were crude but show that friction is the real enemy and a simple configuration such as a single speed can help lower it by a significant amount.
I want to improve my measurements to get a better estimate of the difference in power so stay tuned.
Mike
I wanted a more quantitative measure of the difference than just the above observation. So I attached a weight to the pedals and measured the amount of weight needed to take the pedals from horizontal to vertical in 1/2 a second. What I found was that the derailleur took 4 times as much weight. This means that the power output needed to just turn the pedals is 4 times more for the derailleur than in the single speed setup.
Next I tried to determine the actual power needed. This was a very crude estimate but I came up with 16 Watts for the derailleur verses 4 Watts for the single speed. The difference of 12 Watts is power that is not going to moving the bike but is needed to just overcome drive train friction.
At the Iola race an additional 12 Watts of power for me would have translated to reducing my race time by two and a half minutes. That would have moved me from fifth to third in my age group.
All these measurements were crude but show that friction is the real enemy and a simple configuration such as a single speed can help lower it by a significant amount.
I want to improve my measurements to get a better estimate of the difference in power so stay tuned.
Mike
Sunday, May 8, 2011
A Recovery Week
This week has been a recovery week. I have had four hard training weeks in April and following the Iola race I was very tired. Also the semester is about to end and that means things are very busy at school, so this was an ideal time for a little rest. Tuesday I did a recovery ride and then again on Thursday with Monday, Wednesday and Friday off.
Saturday I did a very intense one and a half hour tempo/threshold ride on the road. Then today I went to the trails in the Northern Kettles for the first time this year. They are finally open. All the rides this week were with the 1x9 geared setup. My plan is to keep the 1x9 setup on for the coming week to get some baseline PowerTap data and then go back to the single speed setup next weekend. That way I should be able to compare geared to single speed performance under similiar conditioning.
One interesting thing I've noticed is that with the single speed setup The crank will easily spin backwards several times with an gentle push compared to only about a half turn when I have a deraillier setup. This shows that there is more friction in the geared configuration. I want to see if I can figure out a way using the PowerTap to measure just how much additional friction there is with the deraillier. I have an idea how to do this but we will just have to see if it works.
Back to harder training this week.
Mike
Saturday I did a very intense one and a half hour tempo/threshold ride on the road. Then today I went to the trails in the Northern Kettles for the first time this year. They are finally open. All the rides this week were with the 1x9 geared setup. My plan is to keep the 1x9 setup on for the coming week to get some baseline PowerTap data and then go back to the single speed setup next weekend. That way I should be able to compare geared to single speed performance under similiar conditioning.
One interesting thing I've noticed is that with the single speed setup The crank will easily spin backwards several times with an gentle push compared to only about a half turn when I have a deraillier setup. This shows that there is more friction in the geared configuration. I want to see if I can figure out a way using the PowerTap to measure just how much additional friction there is with the deraillier. I have an idea how to do this but we will just have to see if it works.
Back to harder training this week.
Mike
Tuesday, May 3, 2011
The Iola Race
Saturday I drove to Iola to pre-ride the course. I started with a 34x18 gear which was too big. I could not climb any of the four major climbs on the course. So I changed to a 34x19 gear. This made the climbing better but I could only do 1 of 4 climbs. Then I went to a 33x19 combination. This achieved 2 of 4 climbs. By that time I was too tired to try another lap.
Saturday evening, when I was back home, I changed to a 32x19 gear. Then Sunday morning I decided to just put my 1x9 geared setup back on the bike for the race. I felt that I needed some off-road single speed time before trying to race. Single speeding is more than just a bike, there is a definite technique to successful riding.
At the start of the race I was positioned at the front of my wave. The race started very fast and by the first climb I was in the middle of the wave. However, I started passing riders even on the first climb. At Iola you pass through the ski bowl twice each lap. The second pass consist of a fast descent followed by a quick, steep uphill. It is essential to hit the bottom of the hill as fast as you can to make good time to the top. On the first lap I descended at 31 mph. However, when I reached the bottom of the climb the course was filled with walking riders and no way around them. I had to skid to a halt and run my bike up the hill. After that the course was clear for the rest of the race and it was a "go as fast as you can" for the race.
At the end I finished 5th out of 9 in my age group (60+). I was 4 minutes from the winner of the age group. Each lap was faster than the previous lap which is a good sign. It was a good time and it was great to see everyone after a long winter. The one sad note was that the fastest rider in the 60+ age group, Wayne Fish, passed away over the winter. Wayne was a real competitor. I never beat him but always looked forward to trying to close the time gap each race. Wayne will be missed.
As to the single speed, I plan to get some off-road training rides in now that the trails are open and hopefully be really to try a race on the single speed next time.
Mike
Saturday evening, when I was back home, I changed to a 32x19 gear. Then Sunday morning I decided to just put my 1x9 geared setup back on the bike for the race. I felt that I needed some off-road single speed time before trying to race. Single speeding is more than just a bike, there is a definite technique to successful riding.
At the start of the race I was positioned at the front of my wave. The race started very fast and by the first climb I was in the middle of the wave. However, I started passing riders even on the first climb. At Iola you pass through the ski bowl twice each lap. The second pass consist of a fast descent followed by a quick, steep uphill. It is essential to hit the bottom of the hill as fast as you can to make good time to the top. On the first lap I descended at 31 mph. However, when I reached the bottom of the climb the course was filled with walking riders and no way around them. I had to skid to a halt and run my bike up the hill. After that the course was clear for the rest of the race and it was a "go as fast as you can" for the race.
At the end I finished 5th out of 9 in my age group (60+). I was 4 minutes from the winner of the age group. Each lap was faster than the previous lap which is a good sign. It was a good time and it was great to see everyone after a long winter. The one sad note was that the fastest rider in the 60+ age group, Wayne Fish, passed away over the winter. Wayne was a real competitor. I never beat him but always looked forward to trying to close the time gap each race. Wayne will be missed.
As to the single speed, I plan to get some off-road training rides in now that the trails are open and hopefully be really to try a race on the single speed next time.
Mike
Friday, April 29, 2011
It's Here
The first race is this weekend at Iola, Wisconsin. The weather this spring can be summed up in one word: WET. Fortunately, the Iola course is very sandy and so water usually helps this course.
I feel that I have prepared about as well as I could given the weather. The one thing I have not been able to do is ride off road with the single speed. So tomorrow I'm going over to Iola to pre-ride the course with a guess as to gearing. Many people have recommended I start with a 2 to 1 ratio. I'll be close to that using a 34x18 combination. Since my bike is a 29er that combination works out to be a little taller than a 2 to 1 on a 26 inch bike.
I had the PowerTap record from the Iola race last year and I think that the 34x18 gear should work on that course. The pre-ride should give me a good indication if I'm right and, if not, I can change the gearing before the race Sunday.
Mike
I feel that I have prepared about as well as I could given the weather. The one thing I have not been able to do is ride off road with the single speed. So tomorrow I'm going over to Iola to pre-ride the course with a guess as to gearing. Many people have recommended I start with a 2 to 1 ratio. I'll be close to that using a 34x18 combination. Since my bike is a 29er that combination works out to be a little taller than a 2 to 1 on a 26 inch bike.
I had the PowerTap record from the Iola race last year and I think that the 34x18 gear should work on that course. The pre-ride should give me a good indication if I'm right and, if not, I can change the gearing before the race Sunday.
Mike
Sunday, April 24, 2011
A Good Endurance Ride
The weather this spring has been cold and wet; not a good combination for badly needed endurance training. When it is cold out, in the 30's or 20's, I do more short intense rides such as intervals or short tempo rides. That way I stay warmer and don't feel the cold as much. But getting ready for the race season means you need to do some endurance work, in fact you need quite a bit. The heart of a cross country race is endurance.
In April the weather has been terrible and I've only had a few good endurance rides. I think of a good endurance ride as one that is more than an hour and a half in length. This weekend the weather improved with the temperature in the upper 40's Saturday and in the upper 50's today.
Saturday I managed to do an hour and forty minutes at a good pace through some hills. Then today I was able to do a two and a half hour ride on one of my hill courses called Crystal Lake. The course leads south from New Holstein, through the Village of Elkhart Lake, then around Crystal Lake and returns to New Holstein. The total length is 36 miles.
Last year at this time I did this course on my geared bike, so I was able to compare the PowerTap records of the two rides. There are some lengthy flat sections between the hill sections, so overall I would think that a geared bike would be faster. Surprise, today's ride was just as fast as last years ride. On closer analysis, I found that on the flats I was faster on the geared bike, but in the hills I was faster on the single speed. One of the hills is long and very steep at the top. On that hill I was about 5% faster on my single speed. On the other hills I was as much as 10 to 15 percent faster.
I can't explain why I seem to be able to climb better with the single speed, but that is what the data is saying. I have found this to be true on other rides too.
One week to go to the first race.
Mike
In April the weather has been terrible and I've only had a few good endurance rides. I think of a good endurance ride as one that is more than an hour and a half in length. This weekend the weather improved with the temperature in the upper 40's Saturday and in the upper 50's today.
Saturday I managed to do an hour and forty minutes at a good pace through some hills. Then today I was able to do a two and a half hour ride on one of my hill courses called Crystal Lake. The course leads south from New Holstein, through the Village of Elkhart Lake, then around Crystal Lake and returns to New Holstein. The total length is 36 miles.
Last year at this time I did this course on my geared bike, so I was able to compare the PowerTap records of the two rides. There are some lengthy flat sections between the hill sections, so overall I would think that a geared bike would be faster. Surprise, today's ride was just as fast as last years ride. On closer analysis, I found that on the flats I was faster on the geared bike, but in the hills I was faster on the single speed. One of the hills is long and very steep at the top. On that hill I was about 5% faster on my single speed. On the other hills I was as much as 10 to 15 percent faster.
I can't explain why I seem to be able to climb better with the single speed, but that is what the data is saying. I have found this to be true on other rides too.
One week to go to the first race.
Mike
Friday, April 22, 2011
Correlations
Because of my teaching schedule, I usually take Wednesdays off. So this Wednesday I didn't ride and then returned to training very rested on Thursday. I managed two rides on Thursday, first about an hour doing hill repeats and then later an hour and fifteen minutes at a fast, steady, but comfortable pace. The day off made me feel great and both rides were strong ones.
This got me to thinking. If one day off results in really good training rides then what if I took 6 months off? Maybe I could win "The Tour". Then I remembered back when I was a college Junior at Oklahoma State University. That fall semester a friend and I took a beer break each night at 9:00 pm. We each consumed one beer. At that time in Oklahoma beer had an alcohol content of 3.2%. At the end of the semester I earned a 3.2 grade point average. The correlation was obvious.
The next semester in a earnest attempt to improve my academic standing, I tried a bolder approach. At the end of the semester I fully expected a 76 grade point average. Sure enough the correlation was perfect. I made a 0.76 average. I spent the next four years in the Navy. I then returned and repeated that semester drinking only water, no salt please.
I think the only things I'll be taking off are Wednesdays and derailleurs.
Mike
This got me to thinking. If one day off results in really good training rides then what if I took 6 months off? Maybe I could win "The Tour". Then I remembered back when I was a college Junior at Oklahoma State University. That fall semester a friend and I took a beer break each night at 9:00 pm. We each consumed one beer. At that time in Oklahoma beer had an alcohol content of 3.2%. At the end of the semester I earned a 3.2 grade point average. The correlation was obvious.
The next semester in a earnest attempt to improve my academic standing, I tried a bolder approach. At the end of the semester I fully expected a 76 grade point average. Sure enough the correlation was perfect. I made a 0.76 average. I spent the next four years in the Navy. I then returned and repeated that semester drinking only water, no salt please.
I think the only things I'll be taking off are Wednesdays and derailleurs.
Mike
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