Wednesday, December 24, 2014

Touring average MPH versus rolling MPH

Since I started riding, I've kept stats on various aspects of my performance.  It started because I was training to complete a century, and the sessions each week with Team in Training got progressively longer, with suggested mid-week workouts to increase our fitness and strength.  So it was very natural to have that material as a record of my progress:  I put the miles and time on my calendar as a way of tracking progress toward the goal of completing the Tahoe Century in early June.

Of course, once I completed that event (somewhere, my time and average mph is recorded) I was hooked.  We did some additional riding on our way home from Tahoe - I think we climbed Conway Summit from Bridgeport (elevation is naturally written down somewhere in my early log book!) and on it went.

Some years, I have kept meticulous records of all my rides, as I am part of that group that rides often and long enough where it begins to be something of a binding topic of conversation:  "Are you going to hit 10,000 this year?" (Not me!  That's Jim James's goal!)  Other years, not so much.  Roger has all this on his computer because we use a Garmin when we ride and he downloads all the stats after we get home.  He usually asks, as we are approaching the end of a ride, "what's our average?"  And usually, I reply, "14.5 mph."  Or something very close to that.  While we are lately creeping up a bit, and yesterday came in with 15.4 mph, I'd say that tandem, pretty much any day of the week, is going to do the hills and valleys around here at just about 14 to 15 miles an hour.  Anyway, this all brings me to the question, "how fast do you have to go to complete PBP?"

I've done some noodling to figure out how we get through 1200 km in 90 hours.  Since my brain runs better on "English" than metric, I have translated the kilometers to miles.  1200 km = 744 miles.  When we did our bike tour up to Lake Tahoe and back, we rode over 1200 miles at an average of 12.5 miles an hour.  That was fully loaded, with 52,000 feet of climbing.  So I figure that is a safe value to use as our PBP average mph.  We can surely make that if all we are carrying is toiletries, tools and a couple changes of bike clothes.  (And the odds are that we can go faster, as our training rides here in Redlands show.  But more on that later.)

The wonderful thing about that particular rate of speed is that it requires you to spend just about 60 hours riding your bike, and leaves you 30 hours for resting.  Over the four day period, it seems pretty workable.  We would get 7 to 8 hours of rest each night, and we should still be able to come in under the 90 hour time limit.  That's what I am banking on.  I just don't see the point of riding through the darkness, and it really should not be necessary to do much of it.

Anyway, this is how I am trying to approach it:  ride a reasonable pace, stop every hour to stretch a few minutes, stay rolling for two-thirds of the day, and get off the bike altogether for the other third.  That seems doable to me.

When we were riding home yesterday (42 miles, 2200 feet of climbing, 15.4 average mph!) I started thinking about this plan.  I realized that calculating the miles we would cover each day based on an average mph like we usually calculate could put us in trouble.  That is, we have set the computer so that it stops recording when the bike is stopped.  We only count the time we are moving.  This is our "rolling mph" on a bike ride.  But obviously, we do stop.  We stop all the time.  We stop at traffic signals, we stop to take a break, we stop for water.  If we are touring, we will stop for meals.  So I realized that it's probably pretty important to get a sense of what our "touring mph" is.  That would be the average number of miles covered while you are out on the bike, including all your stops.  For instance, when did we make it back to the coffee shop yesterday?  Take the total time, divide by the miles.  That is the value that matters for this long-range cycling.

Of course, I was just thinking about this, and I didn't make note of the time.  But it's fairly consistent that our group will go out and do a 40 mile ride and be back by 11:15 or 11:30.  That would be around 13 miles an hour - good enough for my model.

To test my math, I took another look at my notes.  You have to be able to do 200 plus miles a day.  I've figured that would take 16 to 17 hours "on the bike" - which is the term I am using for that part of the day that we are dressed, rolling out, and not stopped to shower, change and sleep.  But that 200 miles, at our historical "rolling mph" of 14.5, will only require something under 14 hours of rolling time, the way we usually track it.  That will leave us with two hours for the stops, water breaks, refueling, etc - and result in the "touring average" of 12.5 miles per hour over the entire period.

Ya gotta love math!  There is just something so comforting about being able to calculate stuff, and know that your numbers do not lie.  I can sleep comfortably at night, knowing that we'll have time during the day to eat and rest a bit, as long as we continue to be able to ride 14.5 miles an hour - on average - while the wheels are turning.  And that doesn't seem too hard to imagine, at all!

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