Efficiency Losses on the Bike

paralysis by analysis

dude, stop thinking and just train.

factors that can impact pace:  clothing, your position that day, tire pressure, wind, air temperature, humidity, moisture level on the road, how your power was applied

there are just too many variables to figure that out with one test.  if you kept a journal of these conditions clothing selection etc, then maybe you can look at a good larger data set. i.e. minimum 10 rides

Interesting findings.  Thanks for sharing.    

I don't have a power meter so the only way I can measure effort on the bike is with my heart rate monitor.  I have found results with the HR monitor that were counter intuitive.  In training I cycle three days a week.  Two shorter rides on week days and a longer ride on Saturday.  On one short short ride I rode fairly hard with a 127 BPM average HR.  Two days later I was feeling worn out and took the ride on the same route very easy with a 114 BPM average HR.  The 127 HR day I however had a 19.0 MPH average speed and the 114 HR day I had an 18.75 MPH average on the same route.  

Another ride on that route a few weeks later had a MPH average of 19.5 BPM at a 123 average HR.  That seemed to be my most efficient way to ride the route.

I did a long ride on a Saturday that was two loops of the morning route which also showed interesting results.  The first loop I had a 17.0 MPH average with a 170 BPM Heart rate (No Idea how I was able to get the heart rate that high), the second loop I was tired and just focusing on staying relaxed and keeping the cadence up and my average speed was 17.5 MPH at a 130 BPM HR. 

So when I try to muscle my way through a work out it increases my HR and it increased my speed too for a short time but I get fatigued and my average speed over the whole ride ends up being slower.  When I ride conservatively my HR stays lower and my average speed over the length of the ride is higher. I am still learning the sport of cycling and will be experimenting with a lot of things this spring.

Note:  I bike in the same set of cloths about every ride.  I record faster times with my tire pressure at 80 PSI than I do with tire pressure at 110 PSI, but that may have to do with the roughness of the road I am riding on and on race day when I am not on my country road optimal tire pressures may be different.  At any rate the tire pressure only factors about 0.1-.2 MPH in what I see so I just set it at 90-100 PSI and don't worry about it.

:-) good post!

After I raced Galveston 70.3 last year, Marc looked at my bike data and said "you're less aero than I am", which was funny because I'm a fairly small girl and should be decently aero.  Like he said, I did a lot of testing up and down a three mile stretch of road.  I have a list of how many minutes various things will save me over the course of a HIM bike split at my power (i.e. not something useless like how much time this would save me at 30mph).  A couple minutes here and a couple minutes there really add up. 

I can't tell you how many people told me "you can't aero test on the road" or "you need a wind tunnel to do that", but in the end, it didn't matter.  The testing was good training itself (I did all of it at projected HIM power), so even if it didn't give useful data, it was still good training.  And if you don't think aero testing on the road is worthwhile, tell that to my bike split

The training helped quite a bit.  You could have gotten the data, without the training, in a wind tunnel.  I understand your point and I'm sure you learned a ton about what is aero for you....but I spend a lot of time around folks who can put up the fastest bike splits at many races, and they don't spend any time, to speak of, working on what is aero for them.  So tell that to their bike splits.   

Yeah, and he rode 2500 more miles that year so there is that.....and it was the ONLY time he ever beat him so there is that too.   LMAO

You guys love the N=1 when you think it makes your point.....can't stand it otherwise.

I don't blame you. 

Look, there is NO WAY anyone who puts in 750 more miles of training, trying to test what is more aero or not, on the road, with ever changing conditions, can say for sure if it was the extra training or the new clothes that made the biggest difference.  That's just silliness.

Since you've had at length discussions about training methods with everyone who has responded here so far you know they value power output, so confused about what you're trying to say here?

you can grossly make aero adjustments in this way, with many repeated trials.  However, a 5 degree change in wind direction impacts yaw angles, completely throwing off any aero "data" you think you've collected.  minute adjustments are essentially untestable in this fashion without advanced, precise, equipment.

No, it takes BS to get the bullcrap out of what you post and get to the meat of it.  You started by saying that you knew a person who's good bike split was because of the 750 miles of aero training/testing she did and then ended up cyber sourcing Chung and Francioni as if they had anything to do with the original 750 miles of training/testing leading to an improvement.  No.

OK, you can work on your power and aeroness at the same time, that's not exactly a revelation.....just don't try to tell me that you can say which of those values is worth more under any condition in any race.....THAT'S where the real BS is!