RChung

One of the things that can be hard to understand is conserving your energy for most of the time and then spending it at the best time is faster. That's especially true when racing, but still applies even if you're not.

surak

OP has a Kickr, so training indoors is always an option to make the power go up. Pacing outside with a PM doesn't mean s/he goes slower over a whole ride or even a climb, in fact it can make all the difference in the world if s/he's between blowing up and being able to finish a ride, with her/his friends also benefiting from not having to slow way down or wait progressively longer at each regroup. Not every ride has to be a training ride.

Plus Assiomas are well under $1k now, so they aren't that bad of a deal.

Seattle Forrest

​​​​​​This is what it boils down to.

chicagogal

I never said that every ride has to be a training ride. I said that a PM is a training tool. Thank you for explaining to me how to pace a group ride. I have only been riding/racing at a high level for 15 years, so I still have a lot to learn.

surak

I'm sorry you think I was trying to explain group ride pacing to you, rather than to the OP. I was merely pointing out that a PM can be used to do more than push over one's limits. In fact, as many posters have already affirmed, it can be used for exactly what the OP wants to do. I quoted your post because I disagree with your narrow perspective on what a PM can be used for.

RChung

The PM isn't just a training tool, or needn't be. It's true that most riders use it just as they would a HRM but there are things that you can do with a PM you can't do with a HRM.

And, despite riding/racing at a high level for 15 years, it appears you didn't know that, so I guess you still do have things to learn. You're welcome.

colnago62

gregf83 

Unfortunately, riders with power meters have figured out that the benefits of staying with pack on a steep climb is not a big enough advantage to justify going into the 'red zone'. Consequently you'll see Froome and others let an attack go while they continue to hold a steady power/pace that they know the others can't exceed over a longer period. So the choice of 'getting dropped' is often the right one.

chicagogal

gregf83 

I meant 'unfortunate' for the fans as it makes for duller racing.

Seattle Forrest

​​​​​​There are two ways to go faster on a bike. One is to make more power, as you say. The other is to need less power. A PM can help you on either front.

With a speed sensor, a power meter, and software, you have a portable wind tunnel. @RChung invented a very clever method of getting to your cda with speed and power data. He shared the (surprising to me) finding that leaving the last 3/4 inch of your jersey unzipped costs 10w at TT speeds. Since learning that fact, I always make sure mine is fully zipped when I care about time. A power meter making me faster, without any training whatsoever. Same goes for your position on the bike which is obviously the big one.

And for people who have to work to reach or maintain a healthy weight, the ability to know how many calories you're burning can help you make it up hills in a timely manner. Seriously, an HRM can be off by hundreds of percent on this.

Finally, you don't have to spend $1k to have as power meter. They can be had for $400 and prices are still falling.

So, I disagree that they're only useful for training.

jadocs

......So in summary OP, yes a PM is very useful

chicagogal

chicagogal

Atlas Shrugged

I have been using a power meter for years, starting with a PowerTap and now on my 2nd Power2Max. I don't race or even take any events I participate in seriously as far as time is concerned. I love having a power meter as its more information to help make my rides interesting and enjoyable. I live in a mountainous area and enjoy longer distance endurance style efforts so pacing and data help hold things together for me. Also besides the usual information, the ratio of power to heart rate is something I take seriously as a gauge of my fitness as well as health. Like all information, it is a personal preference and none of it is necessary or ranked as more essential than the other whether its heart rate, speed, average speed, distance, time, total elevation, rate of climb, # of shifts, ect....

RChung

I don't think I said 3/4". I think I said a couple of inches. I don't remember exactly how far down the zipper was, but probably something like the width of two or possibly three fingers. Not much, but on me 3/4" is one finger's width. I suspect it was because when the zipper isn't all the way up I get wrinkles in the fabric around the collar and a bit around the top of the shoulder -- it wasn't like the jersey was so loose around my neck that there was an air scoop. Wrinkles are really slow. I was at a wind tunnel recently, and the topic of clothing came up so I mentioned this to the guys there. They confirmed that they'd seen about the same size effect in the tunnel, which was nice.

Dheis

For a completely different reason - As a bikepacker, I push a lot of air when loaded up. I've made some fairings and packs to help with aerodynamics but have no way to gage the effectiveness of different designs. Power meters would solve that problem but they're tooooo expensive.

RChung

If you absolutely can't afford a power meter and you absolutely must know there do exist protocols that can help you estimate aero drag without a power meter (but they can be a big hassle, which is why most people don't do them).

Dheis

OBoile

I don't race, but I love my PM. I like seeing the numbers, plus, despite not racing, I am training to be faster, so it's nice to see concrete changes in my performance.

RChung

The general method is discussed on pp 106-108 here, but there are some spreadsheets and sites on the intertoobs that implement it. It's kid of tedious to get it right, and I have a power meter, so I've only done it without a power meter a couple of times, just to prove that it works.

Dheis

RChung

In the case of a power meter, you get both speed and power, and you can both roll down the hill and ride back up it -- so, yeah, the power meter is easier. In the case without a power meter, you're coasting so the power is zero -- but it means that CdA (and Crr) estimates are based only on your speed. That's a heavy burden to bear so you really need the speed to be measured accurately and precisely, and you need there not to be any unmeasured disturbances, like wind or passing traffic or usage of your brakes. Sometimes you can find a sheltered hill where there's no wind, and you can avoid using your brakes (except at the end of the test segment) but, in general, GPS speed isn't going to be accurate or precise enough for this: you're going to need a cheap speed sensor and you'll have to measure wheel rollout carefully. Then, the thing about this protocol is that you will want to take a couple of runs where you start off slowly, and other runs where you take a running start and start the test segment at a fairly good speed. It's the difference between slow speed and fast speed that gives you "independence" in the equations. There are three unknowns (CdA, Crr, and slope) so you're going to need at least three independent equations to solve for these three unknowns, so you'll need to make at least three runs at different initial speeds.

Dheis

john m flores 

Me too and there's something liberating about being old and slow.