Friday, August 16, 2013

Weight in Seconds

Sitting at the computer, still icing my FUBAR wrist, I started thinking about how I no longer perceive the weight of cycling related items in terms of pounds or grams. I see them in seconds, on Mt Washington. This came about when I was forced to add bar-ends to my MTB handlebar to accommodate my injured wrist. How much is this 70 gram addition going to cost me on Saturday?  I "re-calibrated" my gram scale to display in seconds to see what some common items cost me on the Rock Pile.

Let's assume my target finishing time is 65 minutes. That's 3900 seconds. Let's also assume that my total weight - bike, body, kit - is 178 lbs, or 80,725 grams. Thus each gram contributes 3900/80725 = 0.0483sec/g cost to my climbing time. For small variations, say less than 10% around this nominal, these assumptions hold up quite well in reality.

So given a gram can make 48.3ms difference in my finishing time, let's look at a few items. First, the bar ends. You can see my scale says they weigh 3.4 seconds. Trivial, you may say, given the climb will take more than a thousand times longer than that. I set a pretty high bar for myself this year, so every second gets scrutinized. Given my current situation with a fractured wrist, a tiny increase in weight that lets me be more comfortable on the bike and maximizes my output power will more than pay for itself.

I fretted over whether to run a GPS. As they say, if you can't Strava it, it didn't happen. I always like backup too, Ascutney hillclimb case in point. The timing mats never picked up my tag. Do I want to add another 3.1 seconds to my time by mounting a GPS? If I had a light enough power meter, I'd definitely do this. The GPS by itself isn't going to give me any useful real-time info. Still on the fence with this one.

I've been trying to eat clean all week. You never want to diet, as in try to lose weight leading into important event, but when you back way off on training volume, it is east to overeat and gain a little body fat if you are not careful. I did eat a donut this week. Icecream sandwich too. Doh! So much for eating clean. Let's assume 100% of this 380 calorie donut is absorbed, are excess and converted to fat. This would add only 2.4 seconds to my time. Was it worth it? Absolutely!

Now lets look at the kit. Helmets are mandatory. There is little variability in high-end, modern helmets. They all get tested to same standard and have about the same amount of Styrofoam in them. What does this bucket cost? Surprisingly, quite a bit at 16.9 seconds. But what it protects is priceless.

How about shoes? These are lightweight road racing shoes with Speedplay cleats. They entail a much bigger hit at 31.6 seconds. I bet most riders don't think about this. They's spend $10 per gram shaving weight off their bike, but they could probably spend far less shaving weight off their shoes/cleat/pedal system. This has me wondering if there is some super light platform out there where you could ride in minimalist running racing flats and save a pound.

So what does a kit weigh? I put everything into a nearly weightless bag. This includes shoes, helmet, bibs, jersey, gloves and sweat band. It weighs 69.6 seconds. Not as much as I thought, actually. The majority of it is in the shoes and helmet. Many don't wear gloves, but I like the added security of grip I get, as I tend to sweat profusely.

So there you have some measures for thought. Looks like a stellar day on tap for the climb Saturday, cool with relatively calm winds. I'm rooting for Cameron, who I suspect will be going for the course record. Hope he's recovered from his phenomenal finish at Leadville last weekend.


Anonymous said...

Do you make sure to take a big dump before the race? How many seconds is that worth?

DaveP said...

Mmmmmmmmmmmmmm....donuts. Yum, yum.

Good luck, HJ.

Hill Junkie said...

I weighed in pre- and post-dump one time just to satisfy my morbid curiosity. That one was worth about 40-45 seconds! Typical I think is more in the 20 second range. Every bike racer knows how important this is!

dkpisko said...

Good luck!