Monday, January 13, 2014

Cycling: Do more expensive wheels make you go faster?

Cycling: Do more expensive wheels make you go faster?

When its possible to spend huge amounts of cash on wheels, does it make any difference?

When I got my new bike it was supplied with dirt cheap Shimano Alex wheels. I'd already budgeted for better wheels, initially Mavic Krysiums, but when they were not available, Fulcrum Quattros.

Before I fitted the Fulcrums, I'd done 40 rides with no changes to the bike, so how did the first 40 on the Fulcrums compare?

Shimano Alex wheels - $100 (40 rides):
Av moving: 25.84
PWR Av: 168.53
HR Av: 118.75

Fulcrum Quattro wheels - cost $350 (40 rides):
Av moving: 26.24
PWR Av: 169.5
HR Av: 114.7

Average moving speed is up 1.5% from 25.84 to 26.24. Hmmm not much...

Power has gone up a mere .5%.

More interestingly the heart rate to produce that speed and power has gone down from 118.75 to 114.7, a decrease of 3.4%.

Maybe it stems from being a mainly social rider, the speed I ride requires a certain power, and the "benefit" I get is from a lower heart rate.

However.... it means really I get less benefit, so a double edge sword. Its ironic that improving your bike leads to a reduction in its benefit to you.

Time to get a single speed steelie ie a worse bike!

In the meantime, I decided to focus on working hard by trying to keep my heart rate up.

In the last 40 rides (same bike with the Fulcrums):

Av moving speed: 26.82 up 3.8%
Av power: 182.2 up 8.1%
Av heart rate: 120.9 up 1.8%

NB: heart rate from Garmin Edge, moving speed and power from Strava

Sunday, January 12, 2014

Cycling: SPDs vs Clips - which is better?

I'm sure its a question asked many times... As it happens I can do a small test.

When I first got my current bike I wore toe clips, and did 25 rides using them. Then, changing nothing else on the bike, I switched to Shimano SPDs. In that configuration I did 40 rides.

So the two configurations were the same, apart from the pedals.

Here's a table



Clips
SPDs
SPDs "better" ?
n
25
40

total distance km
902.76
1450.55

overall av move speed kph
25.84
25.84
0.01
stdev ride move speeds kph
2.38
2.71
0.32
watts / hr mean
1.45
1.46
0.01
average power
175.00
168.53
-6.48
average heart rate
121.92
118.75
-3.17

So how about do they make me faster? Well, taking the total distance ridden and dividing by the moving time, nope, almost no change.

Here's a frequency breakdown of the average moving speed of those rides, normalised to take account of different sample sizes.




Did they cause me to produce more power? Well in terms of watts / hr the answer is, again, no. Maybe this is a function of the kind of riding I did?

What about average power (as given to me by Strava) ? Actually average power went down - shouldn't it go up?

And finally, heart rate (as measured by the Garmin HRM) to produce that power and speed... well I guess good news is that it went down over 3 bpm, though that could be just ascribed to increasing fitness?