Attempt #3 of the season at the Charlie Baker Time Trial. This week I added my race wheels in hopes of achieving Levi-like speeds. Actually 25+mph would be pretty cool too, as long as there’s improvement over the box rims. Conditions looked to be pretty ideal with the daily high temperature hitting 81°F, it was still 78°F at 6:30 PM. A gentle breeze out of the southwest seems to be perfect for this course.
I made a few more adjustments to my handlebars as well. I was a little hesitant because I wanted to quantify the savings of the race wheels, but I just don’t have enough time on the calendar. CTSR is only 10 days away at this point. During signups I got to meet my long time race report hero. The only aero gear he was running was inconspicuous clear packaging tape over his colorful road helmet. Nice. Looking forward to reading that report.
Just before the race I realized that my bike wasn’t shifting below the 14or 15T cog. Something must’ve gotten bumped when I was installing the disc cover. Instead of warming up properly, I spent most of the last 20 minutes before my start resetting my rear derailleur cable. It was completely random and lucky that I happened to have a 5mm hex wrench with me. I got it shifting pretty well and I was only missing the 11T. That’s not really something for a guy looking to average 25mph to worry about so I went on my way.
My plan for the race was to start easy, keep it steady, and avoid any efforts of threshold. It drives me nuts that my average power for 2 hour tempo rides on a road bike is within 5% of my average TT power. Lactic acid just destroys me and going too hard for the first 5 minutes really makes for a miserable ride, especially in the last 5-10 minutes of the race.
Keith does his countdown and off I go, starting real nice an easy at what feels like ~300W but is probably more like 400-500W. After getting up to speed I sit down and look at my Powertap to find that it’s off. Great. I turn it on and it reads 2000W. Awesome!
About 5 minutes in I had Nega Coach’s voice in my head saying that I shouldn’t be under stress in the first 3k. I thought I had started around 270W-280W average, but in review it was closer to 300W average. I was targeting 285W average, so I really wasn’t all that far off. Trouble was, I was hurting. My legs already felt heavy and my heart rate was at 186 bpm. Average heart rate has been around 180 bpm, but it was running high today and I’m not sure why. I knew it was going to be a painful route to the finish.
As I approached Carisle Center a cop cruiser pulled out right in front of me coming off of Rt. 225. He went through the rotary painfully slowly and slowed way down to make a left hand turn shortly after. I had to soft pedal at 150W for 25 seconds, and slam the brakes when he made his left hand turn. It was really difficult to find a rhythm after that.
Monument Road was torture and I was just holding on for dear life. I got over the triple rollers by Turning Mill Road and died a painful death. Heart rate hit 191 bpm and power dropped big time on the downhills. I saved just enough to get over the last hill without totally self destructing and pretty much coasted the rest of the way to the finish.
Official results aren’t up yet, and I’m missing the first 100 meters of data from the race, so I pieced together the first 100 meters from last week to get an idea of how I finished. My unofficial recorded time was 23:31, which is usually about 5 seconds less than the official time. Despite average power being a pitiful 266W (season low), that’s a new personal best for me by 20 or 30 seconds.
Power required to go 40 kph was 262W, which is an improvement in the right direction. Hopefully that’s due to the wheels and not the narrow handlebar position, because those are definitely getting moved out ASAP. I think that may have had a lot to do with my low power and high heart rate. It’s hard to tell if these position changes will have a negative effect on power output until you actually do a real TT effort.
The “POI” figure below compares my actual time to my theoretical time if my power was always exactly equal to my normalized power. This is the first time I’ve ever seen it above 1, so I think my pacing over the rollers is getting better.
Aerodynamically I think I’m pretty close to being as good as I can get without spending another $5k on equipment, but power output is still lacking. I’m getting a good idea of what works for me now, so hopefully next week will be a big improvement. One more chance before it counts.
Thursday, May 21, 2009
Charlie Baker Time Trial, 5/20/09
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13 comments:
Nice to meet you.
I had 294 average riding cannibal. They have me a 9 seconds ahead of you, and I think that all came from the start to Carlisle center. I had a pretty steady stream of traffic passing me on Concord Road and I'd say it was helpful.
What do you turn for cadence? I like to TT at 95 rpm. I think that helps stave off lactic acid, at least for me.
Also, can you pull an air density number for each of the past two weeks out of your data? I went almost 2 minutes faster than last week, with just 8 more watts. Wind? Air density? More cars to draft? Last week I did have a not tight LS jersey and leg warmers, probably the biggest factor.
How would you know your watts, Mr. "I'm waiting for PTs to be sold in candy machines at Star Market for 50 cents"?...
I'd like to try this time trial thing one day. Did you see Cavendish and Hunter's times today in the Giro TT? That's how badly I time trial. Worse. When your muscles twitch only two ways (on or off), time trialing is not fun.
nice meeting you as well. like murat said... you have a power meter?? really?? i guess i don't see the "power meters owned: 0" anymore on your site...
i'm usually right around 90 exactly, but maybe slightly on the under side if anything. i often have breathing issues going much higher than that. maybe that is worth a shot.
i'll look up my air density numbers in the morning. 5/13 air density wasn't bad, but it was still slow for me. i think the wind was a little gusty because my model wasn't as accurate.
if you'd like to send me your power files (csv) for the races i'll run them and send you the summary pages. it only takes about 5 minutes each and it helps me get more data to improve the accuracy.
5/6- 1.202 kg/m^3
5/13- 1.207 kg/m^3
5/20- 1.171 kg/m^3
in the 24 minute range i figure each 1°F difference in temp is a difference of about 1 second on this course.
Thanks. Running some of this stuff through analyticcycling, I'm guesstimating .35 ish for my slow time, and .31 ish for my faster time. I'm not sure that the ls jersey and stuff alone could account for that. The wind was probably a bigger factor. The other thing that I did not think of was that on 5/13 my tailbone was hurting more and my posture on the bike probably suffered.
One reason I like to ride these cannibal is because that's the way you race normally. Master's races are always up the road. Everything I've read lately claims that riding the drops is the most aero, but on 5/20 I used the "pinkies on the hoods" technique on the downhills and it seemed faster. It makes it a bit easier to sit up on the nose of the saddle like a TT bike. I switched to from 44 to 42 cm bars this year too. Look at Cancellara. I think his bars are 40s. His seat is way higher than his bars too. At 50kph under the red kite every little bit helps.
.31 sounds too high to me for 294W avg and 23:30. i'll have to check my numbers with AC. i figure 0.31 is equivalent to 316W to go 40 kph at 70F/35F. you were over 40kph but under 316W. i'm using 0.0055 CR for rolling resistance, that could be the difference. using my inputs i'd guess you are more in the range of 0.285 which would be 289W to go 40kph. you must have some fast packaging tape.
i think i did around 285W average last year running cannibal and i was at 24:51 or so. that was a fast night with a skinsuit too. i run 44's on my road bike. i hate 40's, they just feel wrong. 42's are bad enough. i do have ~10cm of handlebar drop though. maybe in june i'll have to try some more cannibal runs.
i'd really like to see how fast i'd be with all the aero gear but with the comfort of my road bike. i've been questioning if the position change is worth the power drop and if the aero gear is driving the increase in speed. not enough time to test everything!
Sounds like you guys can nail my TT time to within 10 seconds if I share my 20 minute critical power and my weight with you. I don't even have to race!
Sweet.
not without a good handle of your aeroness!
I may not be doing this correctly. My caveman method was to go to analyticcyling and plug in the air density, 86 kg for bike and rider, slope of 0 (so weight is actually irrelevant), .005 for Crr, then .68 for frontal area (this is my estimate). My avg speed for 5/13 was 10.47 m/s. So then I manipulate the Drag coefficient number until it gave me 286 watts required. .52 ends up yielding 289, close enough. So .68 * .52 = .3536. Or is that not the correct way to do it? Using the same frontal number for 5/20, with the corresponding air density, and 11.1 m/s, to get 294 I have to set the Drag to .455, which multiplied by .68 is .3094.
Keep in mind .68 is a pure wild-assed guess. But my position, etc was equal each week, except for the clothing difference.
Jay, love the site. What do you use for a bottle/drinking system on your TT rig?
Thx rob!
I should've posted pictures as I did all this, but my home computers barely work these days. I don't have any water system at all on my TT bike. Usually I can get away with just carrying a single water bottle in my back pocket and refilling once an hour. Most rides on the TT bike stay close to home (or a course), and races are short (<30 minutes), so this seems to work. I did try a camelback once but that hurt my back. If I were doing longer TTs (30-60 minutes) I would probably spring for one of those aero bottles.
Yes I was eyeing those aero bottles also. Have you taken a look at the new Fitchburg TT course? Much flatter, I trained all winter for that hilly TT. It does have one little bump about 2min in that makes the “take it easy” early pacing tough for me to figure out.
i haven't seen it, but the elevation profile looks nice! i actually scheduled a vacation for over longsjo because i'm not a very big fan of the old courses. now they went and changed the 2 courses that i didn't care for! go figure. those early on bumps are tough though.
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