Spin and Coast

In my last post I mentioned a technique for going fast on flats with a single speed. The technique involved alternately spinning fast and coasting. I have now tried this technique several times and it does seem to work. Over a period of 1 to 2 minutes I can increase my average speed by 10% over a constant cadence. However this does require some training as after a minute I'm starting to slow due to fatigue. With some specific training I think I can extend my time to over 2 minutes with minimal fatigue. That should cover most fast flat sections in races around here.

I am also continuing to work on maintaining momentum in turns and climbs. There is a definite technique needed to ride a single speed fast. The bonus is that it will also help you ride a geared bike faster.

Mike

Eau Claire Sport Race: A Reality Check.

WORS #5: The Eau Claire Firecracker had it all: Rain, heat, sun, fast doubletrack, great technical singletrack, sand, mud, everything you want in a mountain bike race. A thunderstorm passed by from 7:00 until 9:00 am with the sport race starting at 11:30. The rain helped the sandy places but made the new singletrack slick and sloppy.

I started in the last wave male wave with riders 50 and over and the clydsdales. The women started 2 minutes behind us. The leadout was fast doubletrack for about a mile. I pedaled as fast as I could but was one of the last in the wave to reach the first singletrack. My 33x18 gear was prefect for the singletrack but too little for the fast doubletrack.

At the start of the singletrack I was last in the 60+ group of eight riders. I started catching riders in the singletrack and worked my way up to about 4th or 5th place after half of the first lap. At that point I was running with several riders that I usually finish with on my geared bike. However, I was gassed. In the end I finished in 6th. My fellow 60+ riders were shocked to see me on a singlespeed. I had a blast.

After the race I talked with Antony Dombromski who finished 3rd in singlespeed and 25/148 overall. he told me that the way to go fast on the doubletrack is to spin up to speed , then coast, recover and spin up again. I had just tried to spin fast for the entire lead out and that left me exhausted.

The overall winner of the sport race was Rodney Moon riding a singlespeed. Rodney finished over 2 minutes ahead of the second place rider. In the women's race Maria Statz was the overall winner. Brittany Nigh deserves special recognition from me. After leading her through some singletrack, she she said it helped following me. She then passed me in an open section and a big chunk of mud came off her rear tire and directly into my mouth.

Overall it was a great day of racing and riding the singlespeed was lots of fun. I have alot to learn about singlespeed technique but that is what makes it fun.

Mike

First Single Speed Race

This weekend is the WORS Eau Claire, Wisconsin race. It will be my first try racing a single speed. I will be entering my age group so I'll be riding against geared bikes.

I think I'm starting to understand what is needed gear wise for the best results. Eau Claire will be a challenge as it has a very fast, long lead out combined with lots of single track with some ups and downs but no real climbs. Gear selection will be very important.

The race is Sunday and I'll pre-ride Friday starting with a 33x18 gear. First, I want to be sure I can pull the hills. Then I want to be sure I can carry sufficient speed on the flats so that I'm not buried at the start. I really like the Eau Claire course and I think it is an excellent one to try with a single speed.

Let the insanity begin,

Mike

The Right Gear: Part Two

In my last post I thought a 33x19 gear might be the optimal gear for me at the Kettles. Today, I rode the 33x19 setup. My previous best time was 41:22 (41 minutes and 22 seconds) with a 34x19 gear. Today it was 40:10. Just the right gear lets you climb, accelerate and still have speed to cover the course in the least time. it pays to play around with various gears to find what is best for you. And just a slight change can make a difference.

Another aspect of single speeding is maintaining your momentum while minimizing your effort. With a little practice you can learn to take corners without losing much speed and to use just the effort needed to maintain your speed. Since each course is different the technique must be tweaked continually. The single speed really forces this on you as any loss of momentum is paid for with a lot of added effort.

Mike

The Right Gear Ratio

The past ten days have been busy. Last Friday I went to Mt. Morris to pre-ride the course for the WORS Subaru Cup. I was setup with a 32x19 gear. The gear turned out to be a little too tall for Mt. Morris as there are a number of short but steep climbs. Since I didn't have anything smaller, I switched to my 1x9 setup and did another lap. Interestingly the times were the same.

I planned to race the next day; unfortunately, I came down with a flu like illness Friday night so didn't race. By Tuesday of this week I was recovered enough to start riding again. On Thursday I went to the Kettles and rode Loop 3 with a 32x19 gear. My previous best time on this loop was 44:13 (44 minutes, 13 seconds) set two years ago with a geared bike. Thursday with the single speed I turned 42:04!

I felt like I could have used a taller gear as I was spinning out in several places. So today, Saturday, I returned with a 34x19 gear and my time was 41:22. However, I felt like the gearing was too much and that a 33x19 might be perfect. I plan to test that gear either tomorrow or Monday.

The challenge is to find the right combination of climbing power and speed. Each course presents its own challenges and that is what makes riding single speed so much fun.

Next weekend there is a WORS race at Eau Claire, Wisconsin and that course should be a good one for my first single speed race. As I have stated before, I will just ride my regular age group but use a single speed. Eau Claire will be interesting as there are no big climbs and there are some fast sections of double track so gearing will be critical.

Mike

Comparison: Singlespeed vs Geared

Last week I had ridden the singletrack at the Northern Kettles using a 9 speed (1x9) setup. Yesterday, I switched to a singlespeed setup using a 34x19 gear. I wanted to get a good comparison between the geared setup and the singlespeed. I also had data from last August when I had set my fastest times ever over the same trails.

The bottom line is that I was faster with the singlespeed. However, just being faster doesn't mean alot as course conditions can affect times dramatically. So I also compared the power readings from my PowerTap. Over the same trails, I averaged about 10 Watts more power with the singlespeed than with the geared bike. This is approximately the amount of power needed to pull the chain through the derailleur as measured on my bike about a month ago. I had measured 12 Watts as the power needed to pull the chain through the derailleur.

Because the power needed to pull the chain through the derailleur is not power that reaches the rear hub the PowerTap does not measure it as part of the power data. The PowerTap only measures power to the hub. If you can eliminate losses before the hub, then the power will pass on to the hub and be recorded by the PowerTap. In otherwords, that power is now available to move the bike instead of just pull the chain through the derailleur. More power should translate to quicker times and more speed.

When all the frictional losses are considered on a bike, a 1% increase in Power should translate to about 0.5% increase in speed. My overall power increase with the singlespeed was 8% while my speed increase was 4%. Excellent agreement.

Of course this is just one example and relates to just this course. The Kettles trails do not have big climbs although there are many very short uphill parts. I plan to do some more runs at the Kettles and try other areas also. I also want to try with a slight gearing change as I think I can do better with a 33x19 instead of the 34x19 gear.

As I collect more data I will give you more specifics.

Mike

I'm Back

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

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

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

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

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

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

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

What's All This White Stuff?

April 19th and it is snowing! I was hoping the trails might open this coming weekend; but, today it has snowed several inches and more is expected tonight. That means my first off road ride will probably be the pre-ride for the Iola race the following weekend.

My main concern is gearing. Since I don't have any experience choosing cogs for a race, it would have been nice to be able to ride some trails to get an idea about gear ratios. So what is my plan? Use a 52x11 gear and a cadence of 80, then all I have to do is miss the trees to win. What could possibly go wrong with that plan?

The really nice thing about single speeding is that you always have a good excuse. Humilliating defeat? "Well, I was on a single speed". Huge win? "And I was on a single speed". You always look good no matter what the outcome. No front, rear, middle suspension, 68 speed, $10,000 carbon marvel can do that for you.

Looking for the Sun,

Mike

Headwinds are Good.

If you want to feel like Superman then ride with a good tailwind. You cruise along at a high speed with little effort. It is quiet and comfortable. So what could possibly be good about a headwind? Headwinds offer a constant resistance to your efforts especially on flats or slight downhills. These are places where you tend to "spin out" on a single speed. Right now I am running a 33x16 gear until the trails open so I spin out around 22 mph.

Today the wind was from the northwest at about 25 mph. It was in the lower 40's and sunny. There is a bike path between my home in New Holstein and the city of Kiel to the southeast. The path is about 2.5 miles in length, lightly used and fairly flat. It starts just a block from my door so I use it for interval training and for getting to various routes on the other side of Kiel. Today I rode easy, with a high cadence, downwind to the end of the path and then returned into the wind as hard as I could. The strong headwind kept my speed down around 11 mph so the return trips took about 10 minutes. Then I returned to Kiel with a high cadence and repeated the hard effort five times.

A great training ride that combined fast pedaling with hard efforts thanks to a good headwind.

Mike

Is a Single Speed Slower?

Each year I try to compare my training with where I was at the same time last year. In the past, I have used such things as time over a certain route or average speed for the same route. However, these are not a very good indicators as they are highly dependent on weather conditions.

Last year I purchased a CycleOps PowerTap hub for my MTB and now I can compare power over a ride, course, or part of a course such as a certain climb or sprint. So when I switched to a single speed I was very curious if the single speed was slower than a geared bike under various conditions.

So far I have only been able to compare various road rides, as here in Wisconsin the ground has not completely thawed and dried and so the trails are not yet open. Right now I am using a 2:1 gear ratio that seems to work well on the short but moderately steep hills in the area. This ratio gives me a top speed of about 20-21 mph before I "spin out" on flats and downhills.

So what is my overall finding so far? On the average I'm slightly faster on my single speed compared to my geared bike rides from last year. The average power output is slightly higher. That may mean I'm just in better condition than last year at this time, but it is interesting.

One worry I had about the single speed was in climbing, but when I compared specific climbs to the geared bike I have found that I'm just as fast on the single speed and have a similar power output. How about sprints? In a short sprint, 10 seconds, it appears that I am slightly faster on the single speed. On longer sprints I am slightly slower as I spin out after 10 seconds or so. It is encouraging and leads me to think I can compete with the geared bikes in my age group.

In a couple of weeks the trails should be open and I can test the single speed on single track, so keep checking back.

Mike

Aligning the Rear Cog with the Chain Ring.

In yesterday's post I wrote that you can align the rear cog and the chain ring by sighting down the two sprockets before you put the on the chain. This will get you close to alignment. Once you have an approximate alignment you can easily fine tune it using the following technique.

Put the chain on the bike and spin the crank several times. Then notice the position of the two sprockets teeth in the chain. If the chain ring and the cog are properly aligned then their teeth should be in the middle of the chain. If the teeth on the cog are on one side of the chain and the teeth of the chain ring are on the other side of the chain then the sprockets are misaligned. If this is the case, slip the rear cog over in the direction that would move it's teeth to the center of the chain. This is very easy using spacers on the freewheel.

Now spin the chain a few times and recheck the location of the teeth. Keep moving the rear cog until the chain is always centered on both sprockets after spinning the crank. Now you have alignment. Remember that a well aligned chain has the least amount of friction so spend a little time to get this right. Good alignment also minimizes the chances of a chain derailing.

Good Luck,

Mike

Building the Bike

Three years ago I wanted a 29er (29" wheels) and decided to buy a Specialized Stumpjumper Comp 29er. After riding the bike for awhile, I felt like I didn't really need all 27 speeds so I removed two of the front chain rings leaving just the middle ring. This resulted in the bike having only 9 speeds. For two seasons I raced the 1x9 setup sucessfully in the WORS series. Then last year I started experimenting on training rides using only one gear. I found that I was just as fast as when using the 9 speed setup. So this spring I decided to turn the bike into a true single speed.

The first problem is dropouts, those slots that the rear axial fits into, are usually vertical and so you can not adjust the chair tension by moving the rear wheel forward or rearward. However on the Comp 29er the dropouts , although vertical, are adjustable so you can slide them to adjust the chair tension. This made the conversion easy.

I bought a conversion kit for the rear wheel that consisted of a set of spacers, a lock ring and a cog that replaced the 9 speed cog. I also bought a new chain opting for a single speed chain which is wider, stronger and has less side flex than a 9 speed chain. Then I bought a single speed 34 tooth chain ring for the front that had no pins or ramps, devices that aid the deraillier in changing from one ring to another. Finally, I purchased a chain guide for the front ring from Mountain Racing Products (MRP) to help insure that the chain did not derail. The total cost was about $150.

The conversion took about 45 minutes to complete. The two things you must be careful of are: First, the rear cog should be directly in line with the chain ring. This can be accomplished by carefully sighting down the cog and the chain ring and adjusting the various spacers provided in the conversion kit. Second, you must adjust the chain tension so that the chain is not loose and flopping around and not so tight as to put the wheel in a bind. This will take a few minutes of experimenting but is fairly easy.

Now the bike is ready and the fun begins.

Mike

The Hardest Training Ride

This afternoon I did my hardest training ride, The dreaded "recovery ride". A recovery ride sounds easy: Ride for 30 minutes to 1 hour at a very easy pace, no sprints, no climbs, don't go fast, just enjoy the ride, smell the roses. The goal is to give your legs a break and time to rebuild from previous hard rides such as intervals, climbing repeats, speed tests, and races.

This past weekend I did hill repeats on Saturday and a 2+ hour ride at a fast pace on Sunday so it was time for some recovery. What makes the recovery ride so hard is that after about 15 minutes you start to feel very good and so you want to go faster and harder. However, it is very important that you continue to go easy so that your muscles are not taxed in the least. This way your muscles can repair tissue and build new tissue, getting stronger. Self discipline is the order of the day. Tonight I feel very good and I'm looking forward to a harder effort tomorrow.

Good riding,

Mike

The Background and this Blog

For the past 7 years I've been riding in the Wisconsin Off Road Series (WORS)mountain bike races. I compete in the 60+ age group as I am now 67. Last year I was getting burned out and after the first race of the season I decided to take a year off. This year I'm back and re-energized but also I want to do something a little different.

Last week I converted my geared 29er to a fully rigid single speed bike. That means it has only one gear and no suspension. Most mountain bikes have 27 gears and at least suspension forks if not full suspension front and rear. My bike is a 2008 Specialized hard tail Stumpjumper 29er which I previously had setup as a fully rigid 1x9. The front wheel is an American Classic and the rear wheel has a cycleOps PowerTap hub. As a single speed, race ready, the bike weighs 20.8 pounds. The original bike with suspension forks and 27 gears weighed over 27 pounds.

My plan is to compete in my regular age group, Sport 60+, with my fellow 60+ riders riding their geared bikes against my single speed. So will I look like an idiot or can I make my buddies question the money they spent on high tech gears and suspension?

Sound insane? It probably is. I plan frequent updates about training and single speeding. The first WORS race is May 1st at Iola, Wisconsin with lots of short, steep climbs each lap.

Stay tuned,

Mike