Gear Ratios

March 14, 2015 5:11 pm

Gearing on a bike might be a bit confusing to some since there are several things that affect how low the gearing is.  There are effectively four circles or gears involved:

  • The Crank Arm.  This is measured in mm, with a valued like 170 or 172.5
  • The Front Cassette, which is usually either a Triple which as 3 rings that have 53/39/30 teeth each, a Double which two rings with 53/39 teeth each or a Compact with 50/34 teeth each.
  • The Rear Cassette.  This also defines the number of speeds, usually either 10 or 11 speed and the smallest cassette is typically 11 or 12 teeth and the largest anywhere from 23 to 36 teeth.
  • The Tire Size.  For mountain bikes theses are either 26 in, 27.5 in or 29 in.  For road bikes these are typically 700c.  It is the outside circumference of the tire that is the factor so a fatter tire will have a larger circumference.

To get the lowest gear you would go with the largest crank, smallest front chaining, largest rear cassette cog and smallest tire.  A gear ratio is defined by the the ratio of the number of teeth (or circumference) between two gears but we effectively have 4 gears at work so to get a lower gear ration you go from a large gear driving a small gear, driving a large gear, driving a small gear.

On a bicycle it is a bit more complicated than if all these were simple gears, in which case the middle gears would be idler gears and not affect anything.  But the connection between the crank arm and the chain ring is direct coupled.  The crank arm acts as a lever and like any lever, the longer the lever the easier it is because the longer the crank arm, the more distance your foot moves on each rotation and more distance for the same rotation means less force, or effectively a lower gear.  Likewise the cassette is directly coupled to the rear tire.  As the tire size decreases, each rotation of the tire means moving less of a distance, which means less force is needed for each rotation of the tire.

When you move to a larger tire size (such as the 29ner mountain bike) the same crankset and rear cassette will have higher gear ratios (harder to pedal) than on a 26 in bike.

The crank arm length is picked based on the rider and the bike tires are what works on the bike.  So all that most riders can change is the chain rings size and the rear cassette range.

There are some online calculators you can use where you put in the crank size, tire size, front chain rings and rear cassettes and it will give you gear ratios.  A lower number means a lower gear (easier to pedal).  These will help you decide if you can switch to a Compact Crank instead of using a Triple Crank.

I was considering to buy a new bike for my wife but her current bike has a Triple Crankset with a11/34 cassette on the rear, which I am able to have her use by installing a mountain bike rear derailleur.  I was hoping to get a bike for her with electronic shifting but the lowest option would be a Compact crank set and a Ultegra long cage derailleur that will work with a 11/32 cassette.  With her current bike she rarely goes into the very lowest gear, but on some of the hills she goes in one gear down (30 tooth cog), so she is using a 30 tooth chain ring in the front and a 30 tooth cog  in the rear.  Plugging in the crank arm length (170 mm), tire size (700×25) that is a gear ratio of 2.1.  Now switching to a Compact crank and a 11/32 cassette, the lowest gear ratio is also 2.1.  So she is only giving up the last gear only although that last gear is relatively big jump.




A Slow Year

November 7, 2014 7:49 pm

Screen Shot 2014-11-07 at 8.43.33 PM

We are now down to about 7 weeks left in the year and I am way behind in my cycling miles compared with prior years.  Last year I exceeded 12,000 miles for the first time.  It started in May when we went on a European cruise.  Then we decided to move to Utah and it seemed harder to find time to bike much.  Now that we have settled down, I have been doing a bit better, but I don’t think I can even catch my prior worse year of 2011.  Weigh is up and mileage is down == slow rider.

Trek Domane Six Series

7:42 am

IMG_1284My Fourth Trek Road Bike

I have had a long experience with Trek bicycles. My first Trek, which was my second road bike, was a Trek 5200, which is still being using by one of my sons. In 2006 I decided to get a new bike, buying a Trek Madone 5.9 for around $4,600 new. That bike came with Dura Ace 7800 components and I thought it was a great bike. The frame later was replaced with the Madone 2009 6.9 series and then later I replaced the components with Dura Ace 7900, moving to a compact crank for the first time.

Which Trek Road Bike to Buy

Using a credit that Trek kindly gave me due to an issue with my other frame, I decided to buy a new bile.  Trek now offers three different road bikes, the Domane, the Madone and the Emonda.  Initially I was intrigued by the lightweight Emonda but I don’t do hill climb racing anymore and had some concern that the lightweight would come at the cost of reliability, considering I don’t get a new bike every year or two.  I had been riding a Madone for 8 years so that would be the safe bet but I don’t like how they moved the rear brake down by the chain stay, requiring using non standard brakes.  I have been intrigued by the Trek Domane with the ISO Speed link that decouples the top tube from the seat tube, with the intent of damping vibration.

Bike Geometry

I took a look at the sizing for my prior Madone and the Domane.


The Trek dealer helped me with a Trek Project One order where you can customize many options. I was only able to test a Domane a size too big for me before ordering and thought my traditional stem length of 70 mm might be too short.  The effective top tube of the H1 Madone is 53.9 cm and for the Domane it is 53.0 cm, so I went with a stem that was 10 cm longer.

Which Components

shimano-ultegra-di2-6870-11-speed-sti-lever-57 Once I decided on the Domane, the next decision was the drive train. I have been riding Dura Ace mechanical for many years and thought about that, but my younger brother suggested I try the electronic Di2. When I checked the Trek Project One pricing I was surprised that the Dura Ace Di2 was an additional $1,732 over the mechanical version so I looked at the Ultegra Di2 and found it to be actually $262 less expensive. That makes the price difference between Ultegra Di2 and Dura Ace Di2 to come close to $2,000. Considering I only spent $4,600 on my last new bike purchase, that seemed like a lot.

Since Di2 shifts so well, even with the Ultegra model, it came down to only an issue of weight for me. With a weight difference of only about one pound, I could not justify spending $2,000 so I decided to go with Ultegra Di2.  One other advantage is that Ultegra offers a medium rear cage so it can handle a 11/32 cassette.  It is not a range you usually need but I wanted that option.

Black on Black

Besides the drive train, Project One allows you to pick paint schemes, stems, saddles, wheels and even things like color of the cables.  I went with one of the four paint scheme options that does not add additional price and selected a matte black with ghost imaging lettering, which is quite similar to the Giant Anthem Advanced mountain bike I bought last year.  I never understood why cyclists who are not sponsored want to have big letters like “S-Works” on their bike.  They don’t drive around a car with big “Toyota” plastered on the side door.




Since I didn’t want everything black, I went with a white saddle and white handlebar tape.

Bike Fit

The Trek deal did a bike fit for me.  I had them lower the handle bar 10 mm by moving a space up above the steam.  It was just too relaxed of a fit for me.  I used that fit for the first couple of rides, then made some minor adjustments, moving the saddle back about 1/3 in and rotating the handlebars forward slightly (back to how it was delivered from Trek).  I was glad I got a longer stem.

IMG_1610I also found the handle bars much higher than on my Madone.  The Frame Stack on the Madone is 54.7 (H2) or 51.9 (H1).  For the Domane it is much higher at 56.1 cm.  I ended up moving 25 mm of spacers above the stem, which would give me a new stack height of 53.6.  That is still more relaxed that my old Madone, indicating I did indeed have more like a H1 fit before.   I now have a fit that I feel is even better for me than my prior Trek Madone, with a bit more relaxed fit and and room to adjust even more relaxed as I get older since I anticipate using this bike into my 70s .

Ride Quality

The bike came with 700×25 tires so I am not quite sure how much of the smoother ride is form the ISO Speed and how much from the wider tires but in any case I definitely notice a significant difference.  Some of this might also be due to the 3 cm longer wheelbase.  Once I get a new cassette for the Dura Ace 9000 wheels I bought last year, I do better comparison.  The geometry is also much better than my Madone, which was probably setup too aggressively for me.  Even though I have a longer stem, I can ride on the hoods for a long period of time, whereas before I found myself almost always riding on the tops, except if I were in a pace line, climbing or descending.

Electronic Shifting

I really like the electronic shifting.  On the other hand I heard that the Dura Ace 9000 mechanical shifts very well.  Frankly I think Shimano blew it when then went from the Dura Ace 7800 to the 7900 shifters because I found the front derailluer to be much harder to shift into the big change ring.  This was one reason why I wanted to go with Di2.  Also I am getting older and many older people prefer the Di2 as they might develop some mobility issue with their fingers.

Additional Changes

I Project One ordered the bike with the 11/32 cassette since I wanted to make sure I got the medium cage derailleur.  I don’t think I need that low of s gear since we have moved away from California and it’s steep hills. but but I wanted the option.  I put a Drua Ace 9000 11/28 11 sp cassette (Cost of $159 at Pro Bike Kit) on my existing Dura Ace 9000 wheels and am using currently.  At a 190 grams this new cassette is a big weight savings compared with the Ultegra 11/32 weighing 290 grams.

I had Michelen Pro Race 4 700×23 tires on those Dura Ace wheels and it felt quite different than the Bontrager R4 tires that came with the bike and handling felt more like my Madone.  The R4 tires are also worthless since they are too thin for the area around here and I grew weary of flats.  I wanted some new 700×25 tires, but the Pro Race 4 Service course doesn’t come in that width so I ordered some Pro Race Endurance Course to replace the Bontrager tires on the Race X Lite wheels that came with the bike.

Other Weight Saving Options

I needed a cassette for my other wheels so that was an easy choice to save some weight.  I was wondering if I could replace any of the other components to get some weight savings.  My Dura Ace 9000 wheels are already very light so new wheels is not in the cards.   I did some research on Dura Ace Di2 vs. Ultegra Di2 component weights and there is no clear area where spending additional money will be worth it.  I did get a new DuraAce crank only because there did not look like sufficient clearance for a Stages Power meter.  That cost me $358 and when I weighed the Ultegra I took off and the new DuraAce I put on the difference was only 90 grams.  The wheels I got with the bike are Bontrager RXL, tubeless read.  However the skewers are RL, and weighed a total of 138 grams.  I bought some Enve titanium skewers that I weight at 55 grams, so that resulted in a weight savings of 83 grams, at a cost of only $44 and saved the same weight as switching to a DuraAce crankset.  Di2-Weight-Compare.xlsx

I weighed my new bike after installing the pedals and water bottle cages and my Dura Ace 9000 wheels and it came to 15.8 lbs.  My Madone was 15.3 lbs.  After changing the crankset and the skewers, the weight dropped to 15.6 lbs, almost the same as my Trek Madone with Dura Ace 7900 components.

I also have a Cycle Ops Powertap Pro wheelset I used for training on my Madone.  It was not 11 speed, but I found you can get a $99 freehub to convert to 11 sp so that is on order.  It was very easy to install but I still intend to order a Stages Power meter replacement left crank arm.

The other think I have ordered is tubeless tires and will give a report on those after I get them delivered and installed.

In the end I will have a bike that weights not much more than what I had before, fits me much better, has a smoother ride, and also sports electronic shifting, so I am happy with the changes.

Shimano Di2 – DuraAce 9070 vs Ultegra 6870 Weights

November 6, 2014 9:18 pm

During the process of buying a new bike, I decided to try electronic shifting this time. In the past I have always used Shimano Dura Ace mechanical components so I thought maybe I would order with Dura Ace Di2. However for the Trek Project One website, that change would cost nearly $2,000. With Di2, how much different could the shifting be? So it seemed that the only real gain you were getting was a weight saving. I decided I was not interesting in spending $2,000 to save one pound of weight. Someone then mentioned to me that half of that was the difference in the crankset. That got me curious so I did some research to find out where the weight differences were and how much each of those cost. Turns out upgrading the crankset would be poor investment. The prices are roughly what I could find buying the components online at discount and not the list price. You might find some prices even lower and can use that to make your own comparison. The weights were the best I could find, either on a vendor’s website or better if I could find some cyclist who actually weighed the component after they received it.  For another view, this website lists many of the weights but came up with some numbers that a bit difference but the delta weights are in the same ball park.  I didn’t try to figure out the difference in the wiring harness.  The battery is the same between the two.

The dollars per lb weight saved are assuming you have not already invested in the Ultegra component.  If you already have a new Ultegra 6800 crankset and are thinking to replace it with the Dura Ace 9000 to save some weight, it will cost you around $500 and you will only be saving about 60 grams.


New 27.5 Giant Anthem Advanced Mountain Bike

November 8, 2013 2:29 pm



I just took delivery of my new mountain bike.  I have been waiting for the 27.5 size to become more prevalent.  Being a short guy, I always felt the 29er’s  would be to much to handle for me while the 27.5 looked like it has much of the advantages of the 29er and less of the disadvantages.  I went with a Giant Anthem Advanced 1.  It has Shimano XT 2×10 components, which work great.



Course on Garmin 810 Without a Computer

October 31, 2013 8:29 am

We brought our bikes to Solvang, California, for a short vacation. I have done the double century ride here several times so I was thinking of just doing about 70 miles of that route today. However when we checked into the hotel they handed us a flyer from the local bicycle shop about the “Solvang Prelude”. Doing a search I saw that this cycling event was this weekend and included a metric century ride. Intrigued I found the route that someone had put on

The problem was I had only brought my iPad and left the computer back home. The Garmin Edge 810 does support Bluetooth so if I could get the course onto Garmin Connect, I could access it with the Garmin Connect iPhone app and send it to my 810. Initially I thought that would be easy but that was not the case.

On the iPad I went to the course on RideWithGPS and tried to do an export but it only opened the GPX text file in the browser. There was no way on the iPad, which lacks a file system, to make this work. So using two iPads I looked at the course on one and manually started to create the course inside Garmin Connect on the other one. Half done the Safari browser crashed, losing all my work. I tried again from the start and again after a lot of work a crash. Frustrated I tried Chrome on the iPad and it crashed.

Then I remembered I had Parallel Connect so I could access my computer at home remotely using my iPad. Doing that I opened up Firefox and then repeated the export and saved the route as a GPX file on the desktop of my Mac at home. Then I opened in the browser Garmin Connect, selected courses and the to create a new course. Then I realized it does not support any GPX import. I knew I could create a course from an activity so again accessing my home computer I tried to upload the GPX file to Garmin Connect but that failed. I tried using a TCX export and that also failed.

Frustrate, I then opened the website GPSGypsies, where I was able to convert the GPX file into a Garmin file. They had several options for the output file format.

I tried the two Garmin file options and each failed. I then tried the GPX course file and it failed. Finally I tried the Garmin GPX Track file. That file uploaded to Garmin Connect where I was able to use the activity to create a course.

Then it was back to my iPhone using the Garmin Connect app, and clicked to send to the 810. A frustrating experience but I finally found it to work. The lesson I have learned is the the iPad is high limited and I would be Bette off with a MacBook Air to have a real computer with a USB port.

Clubs on Strava

October 21, 2013 10:00 am
Clubs on Strava

Strava is a great website that uses your GPS based device, including Garmin sports devices and smartphones, to track all of your cycling and running.  It is constantly adding new features for both their free and premium memberships.  For some time you have been able to join a club on Strava.  These clubs have been usually created based on an actual bicycle club, but others are based around something else in common.  I belong to four different bicycle clubs and have therefore joined all of them on Strava.  I also joined other clubs or groups.  You have always been able to compare yourself to others who have aligned themselves with that club on Strava but they now have added a new Leader board feature.   Some clubs have extensive statistics, but only for club rides.  Many of us don’t just ride with one club so I much prefer Strava where it counts all my rides, including when I ride by myself.  Here are the leader boards for the four bicycle clubs I belong to plus two other groups.

1. Almaden Cycle Touring Club (ACTC)

  • Has 133 Strava members.
  • The dashboard for last week looks like this:


2.  San Joe Bicycle Club (SJBC)

  • Has 194 Strava members.
  • The dashboard for last week looks like this:


3. Western Wheelers

  • Has 75 Strava members.
  • The dashboard for last week looks like this:


4. Utah Velo Club

  • Has 44 Strava members.
  • The dashboard for last week looks like this:


5. Low-key Hill

  • Has 148 Strava members.
  • The dashboard for last week looks like this:


6. Randonneurs at Large

  • Has 75 Strava members.
  • The dashboard for last week looks like this:


7. Furnace Creek 508 Veterans

  • Has 20 Strava members.
  • The dashboard for last week looks like this:



Strava Vuelta Skelta Challenge

September 17, 2013 9:38 am
Strava Vuelta Skelta Challenge

I finished the 15 day Strava Eurosport Veulta Skelta challenge.  This challenge was to climb 7,135 meters in 15 days, starting September 1, 2013.  I finished by reaching move than double the challenge amount.  Although that only was 273rd position on the entire leader-board of nearly 10,000 participants, I had the most for all the people I follow and also for my age group.  That is rare for any Strava Challenge since I follow some cyclists who do a lot of biking and many are training for the upcoming Furnace Creek 508.




Cycling Ultimate Interval Training

May 29, 2013 7:49 am
Cycling Ultimate Interval Training

Since there was not nearly as much study on interval training for the bike as there has been with running, I adapted my running training over to the bike.  For marathon training I found mile repeats and half mile repeats to be a good workout, while doing 400 meter repeats for a short race.  So on the bike I used 7 minute or 3.5 minute intervals followed by half that time for a rest interval, and would repeat 4 times.   Many cyclists use a much short interval length.  Of course the length of the interval, it’s intensity, and the rest interval, will all be a factor on what aspect you are trying to improve.  Some research suggests an Ultimate Interval length based off your T-Max.

Before I get into the details, let me first make a case of why you should have a power meter to do this, although at the end I do offer some suggestions for those who do not have a power meter.

Use a Power Meter

With running, it is easy to see your progress by watching your pace for the interval splits.  But with a bike, your speed is dependent on much more than just how much effort your are putting in.  I tried to use a repeatable, mostly circular course to cancel out the effects of wind and incline.  I figured if I averaged my speed during all the intervals that would be an indication of my fitness.  However since I started to train with a power meter, I see that my prior approach is not sufficient.  Take a look at this graph of four workouts done this year, the last few using a Power Meter.  If I based my estimate only on speed I would have thought I had declined during the last interval workout, but I actually improved by looking at the average power of the intervals.


The Ultimate Interval

Now that I have the advantage of using a Power Meter, I can change the interval approach and not try to just do the same course and interval length.  Some studies point to what is referred to as T-Max interval as the basis for the ultimate interval.  See this article in Bicycling Magazine.

Find Your T-Max

1. First you need to determine your Peak Power Output (PPO) by starting out cycling at 100 watts, increasing your power by 30 watts every minute until you reach exhaustion.  You can go by your own feeling on what that point is, or some use a benchmark as when your cadence drops below 60 rpm.

2. Rest for one or two days, then after a warmup, start your timer and ride at your previously determined PPO until you can no longer sustain that power level.   The amount of time you were able to hold your PPO is your T-Max.  For most people that is around four to six minutes.

3. For the Ultimate Interval, use 60% of your T-Max for the interval length and twice that for the rest interval.  So if you were able to hold your PPO for 6 minutes, you would use an interval length of 3.5 minutes followed by a rest interval of 7 minutes.  This is the opposite of what I have been doing.

4. When doing the intervals take your power to your PPO and hold it there for the interval length (60% of your T-Max), then rest for twice the length, letting your heart rate decline down to about 60% of your maximum heart rate.

5. Start out with two to three intervals, doing two sessions a week.  Try to build up to six to eight sets twice a week, with at least two days of spinning or rest between.

 No Power Meter?

Without a Power Meter you will need to just use a nominal interval length, in the range of 2.5 to 3.5 minutes and a rest interval twice as long.   When doing the intervals take your heart rate to 95-100 percent of your maximum heart rate.  The recovery period should be at 60% of your maximum heart rate.  My maximum heart rate is 176 so for the interval I would try to get over 167 bpm and for the rest interval I would be at 105 bpm, which is pretty much how I have been doing intervals.


Strava Suffer Score

May 21, 2013 8:48 pm

The original entry was published on September 1, 2012.  Since then, Strava has made it possible for Premium members to change their heart rate zones.  I have updated this post accordingly.

One of the features of a premium account on Strava is the so called Suffer Score that it will compute for you after each run or ride.  It will only be able to calculate this if you are recording your heart rate because it uses the heart rate compared with your heart rate zones to calculate the suffer score.  For a detailed analysis of what goes into this see Strava Suffer Score decoded, a post written by a friend Dan Connelley.

Heart Rate Zones

Strava now allows Premium members the ability to edit your heart rate zones.  If you accept the defaults that Strava offers, your Suffer Factor might be misleading.  I have done a lot of research on how different coaches recommend setting heart rate zones but no one would put an anaerobic zone starting at 169+ for a maximum heart rate of 175.  Besides, I know that is not the case for me.  Instead of changed the heart rate zones so Zone 5 now starts at 163 not 169.  See my article that compares several methods.  Note once you change your zones in Strava, it will use on a going forward basis and will not change your prior suffer scores.

High Suffer Score Could Mean Poor Condition

I suppose that there there is a correlation between suffer score on Strava and how much you suffered on a ride.  But that does not mean a higher suffer score correlates with better performance in terms of speed/distance.  This was apparent on today’s ride, which had a suffer score of 360.  I sorted my activities in Strava over the past 3 years by suffer score and looked at all of them over 400.


I think the ride where I suffered the most was the on on 7/7/10, but it has the lowest suffer score on this chart.  But then that was done before I was able to change my heart rate zones.  For the two recent double centuries, the one on Knoxville cause me far more suffering that the one for Solvang, but the suffer scores are not that much different.

The suffer score seems to be heavily weighted toward long duration but for some individuals a long ride does not mean suffering, especially if done at a moderate pace.  I therefore consider suffer score just a fun thing to look at and probably a motivator for many people so overall I think it is a good thing.  Strava might consider to look at some other measurement score that could help us with our training, but that might require a power meter which most users do not have.

For those who have a power meter, Strava now offers several new tools to look at, including Training Load and a Fitness and Freshness page.  Once you start to accumulate data from a power meter you will be able to better understand your rides, far more than the Suffer Score will provide.