Monday, June 29, 2009

Post-crash 1 month

Between crash recovery and the heat, my power is still way down. I finally took the time to see just how pathetic things have been of late. Below is a plot of normalized power. Across the board I'm down about 20% compared to the best values over the last 10 months. I'm also down 10-20% compared to the month before the crash. My month prior is showing a little dip in power, perhaps due to the onset of the summer time heat.

The good news is I'm back to doing threshold work and I'm just about pain free. The bad news is I've got a long way to go before my power is back where it should be. I'm thinking I'll be able to make some good gains this week and pop that bottom curve up quite a bit. We shall see...

Thursday, June 25, 2009

Back in the saddle again...

Slowly getting back into riding after 2+ weeks off the bike due to my crash. Fitness has gone to pot and it's gotten a LOT hotter since the crash. A double whammy. Trying to come back in 100+ degree heat is not easy. Per my plan, I came back on regular cranks. I had a major groin injury where sometimes it would hurt to simply apply significant pressure on the pedals. By riding regular cranks I could help the weak leg around if need be.

That said, today (25 June) was my first ride on PCs in nearly a month. 2 1/2 weeks down, a week and a half of regular cranks, and now the Powercranks. So common wisdom would tell you I'd be detrained, right? I mean 2.5 weeks of zero exercise and 4 weeks total of no PC riding. Nope. Legs were perfectly coordinated and absolutely no fatigue in a 90 minute ride this afternoon. Fortunately storms pushed through to drop the temps down to a manageable level or else I wouldn't have lasted 90 minutes. Not for lack of PC fitness but heat related fatigue. I'll say that 90 minutes with no issues is proof positive of PC adaptation, but I know there are some out there who won't have any of it.

Not riding PCs for the last week+ was the right move, and at the same time I confirmed that I was again reminded how PC riding is not the same thing as one-legged drills on fixed cranks. On the way home as I rolled up to my house I was doing some single leg spinning with the PCs. Instantly when I started on the injured leg (about 95% recovered thankfully) I got instant pain. I'd just ridden 90 minutes pain free and the first stroke one-legged sent me cringing. It just goes to show that completely different motions are involved when pedaling with one leg versus pedaling with two legs, even when the cranks are decoupled.

But physics aside, it's coming to the end of the PC use. According to my records, next week will have been one year since I received them in the mail. The data I've collected has shown some things, and it will be compiled and put into one last PC report for the world to see.

Stay tuned

Sunday, June 7, 2009

Crash Recovery

It's been a rough week. The crash I had last Saturday did a lot more damage than I expected. Sunday I just hung out at home, barely able to move at times. Sleeping was a pain. Monday and Tuesday I stayed home from work for fear of moving around too much. Tuesday afternoon I "manned up" and went out for a ride. What a mistake that was. I was barely able to get my leg over the top tube before the ride. The ride itself was incredibly painful. I'd get a pain on the inside of my thigh that would shoot down to the outside of my knee, almost like my sciatic nerve was getting twinged. I could manage only 30 minutes of riding at a whopping 90 W. And that was pushing it! I guess I have to reset my functional threshold down a good 50-60%...

Wednesday was the first day to go back to work, which I did on crutches. I could not walk more than a hundred yards or so before the pain really set in. Plus it saved me from having to look like an animal when I walked. My wife was affectionately calling me "Cornelius" as I walked with an ape-like gait. Thanks.

Thursday was another day at home, too sore from moving around too much Wednesday. By Friday I was starting to feel better, though I still walked like an inhabitant of Planet of the Apes, but of the same kind as Charlton Heston or Mark Wahlberg...

Was forbidden from riding over the weekend, but by Sunday night I'm thinking I may try to sneak in a ride early this week. I still can't walk perfectly, and if I lay on my side I can not perform a side leg lift of my left leg. It's going to take some time to recover from this crash.

On the plus side, I made a freaking good chocolate sorbetto. Whenever I'm in Turin I go to Grom Gelateria (best gelato in the world IMO). The have a ciocolato extra noir sorbetto that knocks your socks off. I pretty much recreated it Sunday. The stuff is deadly.

Tuesday, June 2, 2009

More lube data (actually part 1...)

I recently completed a set of tests to see if there was a difference in lubricants. The lubricants tested included lubricants directly marketed to the cycling market (e.g., Pedros or Pro Link) as well as general household products (WD-40, 3-in-1). A leap of faith is taken in terms of this testing in that it is assumed that the materials sliding against each other don’t matter to the degree as the lubricant. A 440C ball was slid against an Inconel sample on a pin-on-disk tribometer. Dry sliding tests were performed to establish a baseline (dry friction above 0.60). A wear track was developed, and this wear track was used for all tests rather than starting a new track. This was done to keep the effect of roughness in the testing. After a lubricated test, the Inconel sample was cleaned and stripped of the lubricant. A dry run-in test was performed to verify the cleaned sample was free of lubricant and that the dry sliding friction was at least the initial dry value (i.e., over 0.60). Contact force was set at 5 N. Tests were run wet, immediately after application of the lubricant.

The results, quite frankly, surprised me. One of the products was a wax lube. I certainly expected it to degrade quickly, and my expectations were certainly met. But there were a few other surprises as seen in the graph.

A few results stand out. Quite obvious is the increase in friction with KryTech Wax. But surprising is the poor performance of Pedros lube. It performs on level with the wax, and this is a rather popular lube. Obviously not a good one for chains. Another surprise was that as the test went on, Purple Extreme, my current lube of choice, degraded as well. Yet 3 lubes performed very well, either continuing to decrease with time or holding steady. Pro-Link, another popular chain lube, performed best of the bicycle oriented lubes. However, the biggest shock is the performance of household products. 3-in-1 Oil, a household oil, performed well, but not well enough to a product known more as a solvent than a lubricant. That’s right, good old WD-40 performed the best of all. I was completely shocked by this result. Prior to breakdown of the lubricants, some friction values can be predicted, shown in the Table below.

The table confirms what the plot shows; WD-40 and 3-in-1 are the leaders in low friction as well as consistency (as indicated by the low standard deviation). The expected range in the table represents 3-sigma values. Admittedly the low values, particularly for Pedros and Purple Extreme, are suspect. In reality you likely would not achieve friction that low.

So what oil is the best for performance? Well, that depends. Practical experience with WD-40 is that it tends to wear off quickly, but this may be more a function of the aerosol product rather than using the same formula in liquid bottle form. Pro-Link performed well overall, but the cost compared to the household products may not be justified. Nonetheless, just looking at the raw data, you could certainly say the order of preference for lube would be WD-40, 3-in-1, Pro-Link, Purple Extreme, Pedros, and KryTech Wax.

One shortcoming of the test was running the tests in the wet state. In the future I plan to apply the lubricant, leave it for a time, wipe off excess lube, and then perform the test. This is more directly applicable to the typical application for cycling.

Characterization of various liquid lubricants in sliding conditions

  • Test conditions – 5 N mass, 8 cm/sec slide rate for short-term tests, 10 cm/sec slide rate for long-term tests
  • Ball specimen – 6mm 440C
  • Disk specimen – Inconel
  • Lubricants – WD-40, 3-in-1 household oil, Pro Link chain lubricant, Purple Extreme chain lubricant, Pedros Extra Dry All-Purpose Lube

Tribological testing was performed of various commercial lubricants to determine their effectiveness at lowering sliding friction in a standard pin-on-disk test machine. Testing consisted of first characterizing the dry sliding friction between 440C and Inconel, which is shown in Figure 1. Wear quickly develops and sliding friction converges to a value of approximately 0.8. After testing, a wear track was evident in the test specimen.

Figure 1. Sample friction time history of 440C on Inconel with no lubrication.

The wear track developed in the dry sliding test was used for each short-term wet test. Prior to applying a lubricant, a short test was performed to verify friction was on the order of 0.7 to 0.8. Then, a liberal amount of lubricant was added to the Inconel surface in the wear track. The specimen was cleaned, using methyl ethyl ketone and isopropyl alcohol, between tests. Figure 2 shows the performance of various lubricants.

Averages and deviations for the data shown in Figure 2 were computed for the various lubricants. “Best performance” ranges were used. For example, for Purple Extreme, data prior to a decrease in performance was used. Thus, the values represent the most ideal friction coefficients.

  • Pedros – s=0.1381, m=0.0163
  • Purple Extreme – s =0.1119, m =0.0140
  • 3-in-1 – s =0.1028, m =0.0017
  • WD-40 – s =0.0961, m =0.0007
  • Pro-Link – s =0.1106, m =0.0015

Figure 2. Short term testing of various lubes.

Since the above tests were performed with fairly liberal applications of lubricant, selected lubricants were retested with longer term testing and an application that would be typical of bicycle chain maintenance procedures (applying lubricant, allowing time to “seep in” and lightly wiping surface with shop rag). New wear surfaces were used for each test. The specimen was cleaned prior to the next lubricant test. Figures 3 and 4 show the performance of the lubricants tested (Figure 4 magnifies the initial stages). It can be seen from these figures that WD-40 and Purple Extreme quickly broke down and high sliding friction ensued. Figure 5 shows the performance of 3-in-1 oil, which suffered to breakdown and provided a consistent low sliding friction coefficient. It should be noted that in the 3-in-1 test, the slider slid over 9 km relative to the specimen in the same wear track (r=12.18 mm).

Figure 3. Long-term testing of some lubricants.

Figure 4. Enhanced view of long-term test.

Figure 5. Performance of 3-in-1 oil.

Monday, June 1, 2009

Hitting the deck :(

Week started off well. My new approach of "flying blind" when using the PCs has been great. Not being focused on time and power has made riding the PCs fun again. What hasn't been fun, however, is the air quality. Summer hasn't officially started yet, but the Houston air quality is in the crapper. There were multiple ozone warnings last week, and I was certainly feeling the effects of ozone on a couple of workouts. I had to limit my intensity and volume because of it - better to sacrifice some workout time rather than damage a lung. Unfortunately I live south of Houston, and the ozone here always seems to be the highest in the area. There was no coastal breeze to speak of, so the bad air just sat over the area. My throat was hurting and I just couldn't breathe like I wanted.

I did set up the PC bike with clip-on aerobars, and I quickly got adapted to them. I was spinning away with zero difficulty when down on the bars. I'd get off the bars because of discomfort in my forearms (not the best quality clip-ons/elbow pads) rather than any leg issues. Plan was to ride like this for a week and then transition the PCs to my spare TT bike.

But things all changed Saturday. On the group ride we had a few "b-teamers". I have no problem with slower riders as long as they don't cause trouble. On the second half of the ride, my pals were going for a sprint zone. I decided to take the throttle off and just relax a few minutes before we hit a "cobbled" section of 3 miles (I love to drill it there). There were 5 of us in a moderate 24 mph paceline, with me 5th wheel. Wheel #3 swerves (he said #1 and #2 swerved for no reason and he had to swerve to avoid hitting #2) and wheel #4 touches wheel. Wheel #4 goes down and I've got a bike on the ground to the left and front of me and a ride on the ground to the front and right of me. With nowhere to go I t-bone the rider at crash. The good news is that even though I landed hard on my left hip, which I broke in 2002, there was no subsequent fracture. The bad news is I'm REALLY sore several days after the wreck. I had to use crutches Saturday afternoon, but by Sunday I was able to walk on my own. I think I've got a bruised/fractured rib, but the rest is all just minor road rash and a lot of sore/strained muscles. Because of the road rash on my left elbow and forearm, there's no way I'll be using aerobars until the scabs go away.

It's my first crash in a few years, and crashes suck. They suck even more when you're an innocent victim. Lesson learned - don't let those with less fitness get in front of you. These guys were probably tired (we drilled it the first half) and had half their wits about them. I'll just make sure to drop them early next time and not be Mr. Nice Guy.

I'm hoping to get a light spin Monday evening or Tuesday at the latest. The wife isn't too pleased with the crash. I got the third degree when I got home Saturday...

PC time this week - 4 hours 10 minutes
PC time to date - 213 hours 45 minutes