Quarq CinQo Saturn

So, I purchased an expensive power meter...

The flip side is that I can now use whatever wheels I want in races, and get power data with only an 87 gram weight penalty. That's quality.

If you want the full story, head to the Picasa Web Album. I took about 100 high-resolution photos of the installation process, and documented everything in great detail in the comments. I have photos of the packaging, the manual, everything you could want. Check it out!

Quick numbers:
FSA SL-K 39/53 172.5mm crankset with MegaExo BB: 851.3 grams.
SRAM S900 39/53 172.5mm crankset with Saturn and ceramic bearings: 938.9 grams.
Quarq CinQo Saturn crank spider: 154.7 grams.
SRAM S900 stock crank spider: 70.5 grams.

Head to the Slowtwitch.com Forums for great deals on fancy bike parts. That's how I was able to find a CinQo - there are not many out there!

Max Power!

Dieting and training are both going well. I've lost about five pounds since my last power-related posting of about a month ago, making me stronger. I also had an exceptional workout this morning, on account of my brand-new Kreitler 2.25" alloy roller drums. These are roughly 15-20% more resistive than my old 3" drums, so I'm able to push harder in a lower gear without spinning out. I can't wait to see how the new rollers push my training limits. I find that I'm most efficient around 88 RPM on the PowerCranks.

Most of the MIT Cycling team started with base training yesterday morning. I'm still in the middle of my cyclocross race season, so building the sustained power and maintaining my carefully calibrated routine of daily morning indoor workouts is my priority at the moment. Come January, I'll be doing longer roller workouts, perhaps double workouts to gain the correct number of hours, at a lower intensity. I just hope to avoid injury and burnout before the race season even begins!

Averaging over 400W today, this workout represents a massive gain of 14% of my power for an hour. Using a fan while riding, adjusting my saddle position to be higher and more forward, and eating and sleeping properly, all help greatly. My strength is still long-term power. Hopefully, some speed work closer to the start of the racing season will give me a sprint to back my staying power.

Today's morning weight: 176.6 lbs / 80.1 kg.

Time	Wattage	W/kg	Comments
5s	1147	14.31	Moderate (Cat 4)
30s	620	7.74
1m	526	6.56	Fair (Cat 5)
5m*	429	5.35	Very Good (Cat 2)
10m*	414	5.17
30m*	408	5.09
60m*	403	5.03	Excellent (Cat 1)
120m	277	3.46

* denotes power record set today.

Today's "all-out" workout was quite difficult for me, and approaching my limit. My average heart rate was 165, and my max heart rate was 180. As an aside, while I was sitting at my desk doing some preparation for the ride, I saw my heart rate creep down to 45, which means that my resting heart rate has gotten even lower. I'll need to measure that sometime soon.

Indoor Training

I've been quietly but consistently riding six days a week. Unless there is a race or a major event, my plan is as follows:

Mon, Wed, Fri - 60 min "easy" indoors on the rollers riding PowerCranks.
Tue, Thu - 60 min "hard" indoors on the rollers riding PowerCranks.
Sat - 120 min "moderate" indoors on the rollers riding PowerCranks.

It's not very glamorous or interesting, but it's dependable, and it's building a really strong base. At 181 lbs (82.2 kg), I have the following power profile. The "ratings" come from "Training and Racing with a Power Meter" by Allen and Coggan. (I set a new one hour personal record this morning!)

Time	Watts	W/kg	Comments
5s	1147	13.9	"Moderate" (e.g. cat 4)
30s	620	7.5
1m	526	6.4	"Fair" (e.g. cat 5)
5m	422	5.1	"Very good" (e.g. cat 2)
10m	398	4.8
30m	369	4.5
1h (FTP)	334	4.1	"Very good" (e.g. cat 2)
2h	277	3.4

What does this mean in real life? I recently did very well at the MIT team's Wachusett hill climb time trial, and did reasonably well in my first cyclocross race. I have some real long-term power, but need to work in my sprint if I want to compete at a national level this spring.

Aero or Power: Why Always The Choosing?

So, it looks like my "secret admirer" is nothing more than a sham. For shame.

I had a thought today: I really would have liked power telemetry from my Bear Mountain race this weekend (race report forthcoming). I didn't ride the PowerTap because it's mounted to an unimpressive rim, and this race was all about being aero. So I ask: why not rebuild my PowerTap into a Zipp rim?

This is the current project. I'd like to rebuild the PowerTap SL 2.4 into a Zipp 520 rim, the same rim as is used in the Zipp 808 wheelset. Since a PT is so damn heavy anyway, I don't mind making the wheel just a little heavier to gain more aero benefits. By going with the 80mm section, I'll have a fast wheel suitable for all but the steepest road races, and most any time trial or triathlon I attack. By going clincher, I'm able to keep this a training wheel, run heavy tires like the Continental GatorSkins on the rollers, and take the wheel on long rides where flats are the rule.

We'll see if this project comes to fruition. I may very well sell my FP60 rear wheel, as it would be made defunct by this upgrade.

Strength to Weight!

At 81-82 kg, I'm a little heavier than I'd like to be, but still not such a bad weight for bicycle racing. I'd like to be able to hold the "magic seven" of 7 W/kg this weekend at Bear Mountain. We'll see what happens.

As a numbers guy, I've been looking at my power curve lately. According to PowerAgent, this is what I'm capable of developing, in watts, for the corresponding time periods:

1144 W for 5 sec
620 W for 30 sec
526 W for 1 min
375 W for 5 min
358 W for 10 min
335 W for 30 min
316 W for 60 min
277 W for 120 min

This isn't bad, considering the minimal amount of structure to my training, but falls far short of most decent racing cyclists. PowerCranks have helped push this curve up. Notice that major dip around 5 minutes. Hm.

Solution to the PowerTap / Edge 705 Problem

You heard it here first! If somebody makes this and I don't get at least credit for the idea, I'll get lawsuit-happy!

So, here's the problem. I have a PowerTap SL 2.4, a damn fine piece of bicycle telemetry instrumentation. I also have a Garmin Edge 705, which ought to be quite a nice device, except for the fact that it can't read power data - at all - from my PowerTap!

In theory, this should not be a problem. Both of these devices communicate on the 2.4 GHz band and, with some cleverness and payment of royalty fees, I'm sure Garmin and Saris could happily negotiate either a software fix to the Edge 705 head unit, or a hardware change to the PowerTap itself. Rumor has it that this will happen this fall. I'm never one to believe rumor.

So, here's my idea. It's kludgy, and will take some work to implement, but I don't see why it's not possible. I'd like to build a wireless repeater device. Basically, this would function as a PowerTap head does, listening for the data from the PowerTap in real time. It would then masquerade as an ANT+Sport-compliant power device, and relay this information to the Edge 705! The device itself would be the size of a matchbook, run off a CR2032 battery, and probably have a little USB connector for programming the serial number of the PowerTap, or at the very least, a button and a red/green LED. It's a simple repeator-translator, nothing more, nothing less. It's a hack, partially technological, mostly political.

I was turning this idea over and over in my head, and thought to myself: is there any reason why this has to be restricted to the PowerTap SL 2.4 head? Why can't the regular ol' PowerTap SL do the same exact thing? Unlike the 2.4, which communicates directly with the head unit with a range of about three meters, the plain ol' SL communicates wirelessly with a smaller pickup, within a range of three inches, which then communicates via wire. Why not make a device that reads the SL data in real time, and also masquerades as a ANT+Sport power meter, for the benefit of the Edge 705? Not only that, but this device could also speak PowerTap, and basically upgrade a PowerTap SL to a PowerTap SL 2.4! You could even put a little magnetic pickup on the device, for regular old speed, and for kicks, give it the same shark-fin shape.

I tend to rant. I hope my proposal is clear. If not, perhaps ASCII art will work:

PowerTap SL 2.4 --(proprietary)--> PowerTap 2.4 head: this exists.
ANT+Sport device --(ANT+Sport)--> Edge 705: also exists - see the Quarq offering.

PowerTap SL 2.4 --(proprietary)--> Device --(ANT+Sport)--> Edge 705: my idea.
PowerTap SL --(short-range)--> Device --(ANT+Sport)--> Edge 705: also my idea.
PowerTap SL --(short range)--> Device --(proprietary)--> PowerTap 2.4 head: also my idea.

A single device can do all of this.

Definitions:
"Proprietary" - describes the 2.4 GHz protocol a PowerTap SL 2.4 uses to communicate with a head unit.
"short-range" - describes another proprietary protocol, of unknown frequency or characteristics, that a PowerTap SL uses to communicate with a wireless receiver, about three inches from the hub.
"ANT+Sport" - describes Garmin's wireless protocol.

I don't have any time to work on this in May, and I'll be on the road all summer. Perhaps I can work on this when I get back to MIT? The hardware should be trivial, I just need to be able to send/receive a 2.4 GHz signal. Any takers? Garmin or Saris, are you listening?

Power to Mass, that Grand Equalizer

One of my favorite aspects of bicycling is that it is relatively agnostic to a rider's absolute size. For many of the major skills, such as sprinting or climbing, what matters most is not necessarily a cyclist's peak power, but the cyclist's efficiency.

My favorite quantifiable unit here is power (in watts) to mass (in kilograms). When discussing climbing performance, this is the most important number, and one that you can measure directly with your favorite power meter. There are two obvious ways to increase performance here: gaining strength and losing weight.

What other sport can have both a 5'0", 100lb and a 6'8", 250lb individual competing for the same prize in the same event? It's amazing, if you ask me.

The equation is somewhat different on a flat time trial course. Here, since you only need to accelerate once (or twice if there is a turnaround), what matters most is your power to drag ratio. The "densest" cyclist, the most powerful cyclist with the least frontal and total area, will have the advantage here.

Today's ride was a nice example of this principle in practice. Since I lost 45 lbs, I've become a semi-decent climber. I really enjoy being able to climb so much faster than before.