Silvercivic27

Gosh man, durianrider again? You guys are killing me.

Silvercivic27

I actually feel the same way.

bikepro

Obviously it's not meant to be read at one time, however, if you think you may need a PM, you should at least understand Functional Threshold Power and feel a need to determine your own. If this doesn't interest you, a PM is probably a waste of your money.

Silvercivic27

Presumably anyone who actually spends the money on this is at LEAST going to make it that far! That's like buying a heart rate monitor and not bothering to establish your zones. Who does that?

chaadster

I was gonna say, skip the book, get a coach, and get busy training with power.

TheLoneWolf

Never heard at power meters only until recently when joining this forum. It costs as much as a frick'n bike! Although quickly looking, I see there are power meters as low as $150. I wonder how accurate they are in general, also one brand vs another brand. As an average joe, 'wattage' seems kind of nebulous to me. Never heard of that back in the olden days of physical fitness training. That is something that is quantifiable and can be measured & accurately?

I would think physical fitness or getting better at it, involves developing a feel of one's performance. You're tuning in to your body. After awhile, isn't it somewhat intuitive? That Durianrider sure is pushing power meters. He says, he's got them on a few of his bikes $$$$. He also says the primary benefit of power meter, to help him focus on the pacing. Why wouldn't a heart rate monitor, a cyclometer with mph & pacing feature ... used together give similar data feedback? It sure would be a LOT cheaper than a power meter!

Silvercivic27

You hit the nail on the head there, because ultimately this is a question of cost. The fact of the matter is that if an SRM cost $50 like a heart rate monitor, "should I get a powermeter" wouldn't even be a question. Everyone who uses a HR monitor would have one because it IS a very useful piece of equipment. It is just not worth the cost to some people. Is it absolutely essential to be a good or successful rider? At the amateur level, no. Will it help make you a better cyclist faster if you use it for training? Yes.

In in terms of why it is useful to use with a power meter, many of the authors of these various books describe it in a way I don't totally agree with but it gets a point across that the data is different. They describe the HR monitor as measuring the "input" or the effect that a certain workload is having on the body, and the power meter as describing the "output" or the work that your body is actually doing. I suppose this is one way of thinking about it, but in my opinion, I also think of the HR monitor as measuring the effect that your leg work is having on the heart's response to the increased need for oxygen, but in a "delayed reaction" fashion because it takes a while for the heart to respond and recover. They are both very useful to have, and I would not say one is more useful than the other. The point is that they definitely measure different things, and when used together also with RPE, are the best training tools we can use to improve our cycling (along with GOOD analysis software like WKO (NOT strata premium), someone who is expert at interpreting that data and coming up with plans to correct deficiencies... A GOOD coach who knows what the hell they are doing, which is much more expensive than a powermeter, by the way, and you're NOT going to be able to pay for his services by simply patching all your tubes, OK, durianrider?!).

kingfishr

Cyclists pour tons of money into professional grade bicycles and components with minimal impact on one's performance. It's like if everyone would only buy Porsches, Mercedes, and BMW's and somehow believe that 65mph in a Porsche is faster than in a Honda. But a power meter properly used will tell you what you are capable of, when you are pushing to hard, when you need to push harder, and will help you better plan your training and cycling. Unfortunately it has very low bling factor. So it all depends on if you want to impress others or improve your cycling performance.

Silvercivic27

I disagree on a couple accounts. I have a BMW, and I threw the money away when I bought it, knowing full well that it would not get me to work or the supermarket any better than a Honda Civic would, but it takes me there in comfort, and it brings me joy. I paid the extra money for the happiness and the joy. There is value in that, and it was worth the money TO ME.

re: bling status, I also disagree. I think that if you were to roll up to your coffe shop ride with a SR11 SRM and a PC8, there is definitely some bling factor there...

and there are plenty of people out there who want the bling factor AND to improve their riding.

FLvector

If you're not focused and dedicated enough to set up your own training plans and stay with them, or willing to get a coach to guide you and analyze your data every week, then a power meter probably won't be a wise investment. If you do neither, it will just be a cool toy that gives you meaningless numbers that has little value to your daily rides. It all depends on your goals and how serious you pursue them.

datlas 

How else could you know that you REALLY dialed it up to 400W when you gave the guy who looks like Lance "the look" and droped the hamer because he didn't wave??

Homebrew01

If you're not "training", then a powermeter is just blinking numbers.
But it might be interesting to see numbers directly related to you, not influenced by weather, tire pressure, terrain, bike setup etc...
If you want, you can push yourself a bit in a more meaningful way, such as "Maybe I can finally hit 800 watts on this climb ..."

chaadster

I don't agree with this at all, because watts are very easy to understand; the numbers are not meaningless, but rather the most accurate and meaningful way we have of quantifying work. Therefore, even if you don't plan to train to a specific goal, the power numbers will still tell the truth about your effort, and whether you were going as hard or as easy as you thought (i.e. watts vs. RPE). Without power, you could come back from a ride thinking you had a good, hard ride, when in fact (due to exhaustion, nutrition, or whatever) your actual output was under what you normally do (perhaps despite a similar HR). Power would reveal that, and even without a plan, you could say, "Hey, that wasn't up to par; why?" and make adjustments from there.

Drew Eckhardt 

No. It's impractical or not possible to differentiate between "feels hard because it is," "feels hard when you're not exerting yourself enough because you're fatigued, but can dig deeper," " and "feels hard like previous efforts, but you can no longer work enough to benefit and should stop so you're fresher tomorrow."

Heart rate lags power output, drifts upwards over sustained steady state efforts, and varies independently of effort due to factors like heat, hydration, and minor health issues.

Even "dead flat" ground on "calm days" has enough variation in elevation and wind to significantly impact power output needed for a given speed. 5% too hard is the difference between what you can manage for 20 minutes not 60 or 10 minutes not 20. 5% too easy may not adequately stress the systems of interest.

Power also makes it easier to arrive at a pace. Want to ride 4 hours "fast"? CP240 is often 55-65% of CP60. 1.5 hours? CP90 is around 90%. That works regardless of terrain.

"Flat" interval with "no" wind. Note lagging heart rate and significant speed variations:


Riding on a hot day. Note heart rate increasing significantly relative to power:

intransit1217

I just discovered that I can't access the info in my garmin 500 without jumping through 15 additional techno-apps and third party programs.

Clearly a pm is NOT for me.

Drew Eckhardt 

RChung came up with the virtual elevation method for estimating Crr and CdA and otherwise knows a lot about about power meters and training with them.

I agree with his comment - you don't need to read 200 pages to calibrate your fitness (estimate FTP, calculate Critical Power, or use Carmichael's 8 minute protocol), define zones, track training stress, pick a pace, or apply his virtual elevation model.

Training and Racing with a Power Meter is overly verbose.

Heathpack 

I hear what you're saying, and I suppose even without a training plan if you're paying attention, you might get something out of a power meter. But I'm mostly with @FLvector, most of the utility of a power meter is for training purposes.

For example, I use power numbers to hit specific targets during interval workouts. Of course you can do intervals randomly without a training plan but intervals by their very nature are typically used to achieve specific purposes, they work best if theres a "big picture" training plan.

I use power data to some extent on a road ride, but mostly to make sure I'm riding at the intensity my coach has prescribed. You don't get much out of it without knowledge of your FTP. Which means testing or at least including rides periodically that substitute for a test. You also need to factor in all the variables that affect power output- ambient temp, hydration, nutrition, altitude, fatigue on the ride, cumulative fatigue from recent rides vs rest, goals of the ride. It's not just about outputting maximal power on every ride, it's about outputting appropriate power on that day's ride to meet the goals of the ride. It's not even 100% about tracking all this in your software program, because some factors that affect power output (like ambient T and altitude) are not accounted for at all by these programs, you have to factor that in on your own.

So I guess when I think of a power meter and what I get out of it, the maximal effect comes with how it influences/defines my overall training plan and how it is an important language that my coach & I use for communication. Which is not to say that there's no utility for a power meter outside of this context, just that you'll get way less out of it. IMO a power meter is pretty essential for the coached cyclist with a formal training plan. Whether this is self-coached vs hired coach. But for the non-training cyclist, it's very much optional and a matter of whether the cost is a factor for you or not. You will see some numbers which you may understand to varying degrees, depending on how fully you choose to educate yourself. If you're not interested in training, you might be better off spending the power meter budget elsewhere on the bike.

FYI, I got my power meter before I had my coach and when I had a sort-of self-coached training plan. I got it upon recommendation of a BF friend who knew exactly where I'd go with it. But I was pretty serious about my cycling all along, not exactly an "average enthusiast," he was correct in his prediction that a power meter would lead to coaching and an overall better training plan and that all of that would suit me to a "T". He was 100% right, I love training and my coach and power data, it way enhances my enjoyment of cycling 100%. So I'm not saying OP shouldn't get a power meter. Just when I think of "average enthusiast" I don't think of people like me who just keep pushing and training and getting up at 4am to do two hour trainer workouts and frequently can't ride with who they want to because that ride would not meet the day's training objective . I think of the guy who rides a few times a week on a 20-30 mile group ride and really wants to just ride with friends and maybe get better over time. That person can immensely enjoy cycling without a power meter being a vital part of the picture.

gregf83 

If you were a runner before a cyclist and you used a watch to measure pace, you'll probably enjoy using a powermeter as it is roughly the equivalent to a watch for running in terms of objectively measuring performance.

kingfishr

Actually the point I was trying to make is that no one questions that amount of money we spend on the bikes or cars, which are more extravagant then we "need", but a power meter is questioned as being frivelous. Maybe it's like buying the BMW and skipping the ABS brakes...
My power meter has to be the single best investment I have made to improve my cycling period...

Hbrown

Non scientific explanation of why you need a power meter.

They work! Would you want a car without a speedometer or tachometer?

No? What if you knew the horspower of the engine and the rpm of the engine. Would you need a speedometer.

YES. Why? Just think of your output as fuel, say you only had ten gallons and had to go 120 miles. How do you make it the distance?

You watch your speedometer, in this case Wattage, shown by your power meter. Bare with me. I will explain. If I know my car gets 12 miles to the gallon at 60mph, then I can Make it there in 2 hours and use all 10 gallons of fuel. Understand ?

Now if I can sustain 180 watts for 1 hour with relative ease. that tells me a lot! No matter what gear I am in, I can keep 180 watts for an hour. Now I find my cruising gear. With this gear, I can now keep 22mph for 1 hour on my bike. (Wind comes in later). My heart rate at 180 watts is 133bpm, my speed is 22mph and my cadence is 90rpm.

Now this is why the people that race use power meters. They know at what wattage (output) they can sustain, and by looking at wattage numbers, know what , in theory is left in the tank. Makes for one very boring race! Everyone riding at their sustained wattage numbers for most of the race, and then boom!

Lets empty the tank at the end! I now know, because of my power meter, I can sustain 400 watts for 30 min, with my heart rate at 170bpm, so I open up towards the end of the ride! But wait! My maximum heart rate is 200 bpm and at this level I can keep 800 watts for 2 minutes. Now for the sprint! My power meter tells me that for 30 seconds I can do over 1000 watts. Boring race. Exciting end!

Training with a power meter is just another tool in your arsenal. Used with the others makes for a complete toolbox. No good on its own, but with the others devistating!

Just try not to snicker when someone says to you " I had a good workout on the trainer today" " I averaged almost a 100 watts for the whole 30 minutes"!

After you get a power meter, this will be the funniest thing you will ever hear !

gregf83 

I think you might want to check the calibration on your powermeter. Those numbers seem a little low for a race.

FLvector

The metrics generated from a PM initially may have very little value to someone such as the OP who admits that he's an average cyclist who wants to learn more about training and fitness. Especially if he plans to just use the PM to evaluate his actual output in relation to HR (or average speed) of his last ride as you suggest; not money well spent. However, as I said before, if his goal is to train for certain events, or just get faster for his everyday riding, it could be a great tool. If he takes the time and dedication to learn the software and what all the metrics mean, determine his FTP, etc., etc., then it could be a valuable investment. Seems like a lot of money, time and energy just to tell you that your numbers weren't up to par on a group ride. And to get them back up to par, what adjusts do you plan to make? Training plan and intervals which is were this began.

TheLoneWolf

Okay, I quickly searched net and apparently the power meter/wattage measurement principle has been around awhile. I did not know that ... HOWEVER ... or a BIG BUT! -- What about Power Meters from different manufacturers/companies? Will a Hub type Power Meter show EXACTLY the SAME numbers as a Crank Sensor power meter?? Speedometer, heart rate, cadence, mph, altimeter, temperature ... are objective numbers/data, but to me, a PM seems to be subjective-theoretical & variable. I suppose out of curiosity, I should read one of those books about wattage power meter theory but I'm pretty sure my eyes will glaze over!

If I used power meter brand A for so many years then later, got a new bike but decided to use a different power meter brand B on the new bike, will my wattage results read different compared to the other power meter? If so ... then all my metrics results from previous power meter will not be the same and I would have to start over to re-establish new numbers/metrics from power meter B. I can understand if you stayed with one company's brand of power meter and those numbers/data would be consistent.

I know, the rationalization for those who would spend big $$$ for PM, but still, me as an average joe ... $700. to $900. just for this .... ouch!

https://chainreactionblogs.com/diary/...ges_arrive.jpg

At first, I thought the PM came with the computer unit head unit but it does not! I only got a simple cateye on my bike and I can see it can make riding more fun & interesting with the feedback info. I suppose, those higher end cycling computer units with gps & other feedback info, and also, if you included power meter sensor/unit, this takes it to more extreme level. I am not criticizing use of the PM. and only looking at this as a general cycling enthusiast.

gregf83 

It's relatively straightforward to check the accuracy of most powermeters by hanging a known weight off the crank and measuring the torque applied. Some can be adjusted, others you can just be aware that it might be reading higher or lower than spec. Most are accurate to around 1-3%.

Heathpack 

Haha, I'll let you know. I have two Stages power meters right now and an SRM on the way. I should be able to ride with both simultaneously for a little while in which case I will let you know what the FTP adjustment will need to be SRM vs Stages.

Otherwise, I would fully expect that I'd need to ride a new test with the new power meter, because I would assume they will not produce exactly the same numbers. Maybe they will, I honestly don't know. However, this will in no way invalidate any of my previous data.
Is just going to be recorded differently in the future. Nor is it a big deal to ride a new FTP test. It takes 40 minutes and it's something you need to do every few months anyway. Logistically riding a new test may not work immediately with my training plan, I'm prepping for a couple of events right now. But June 7, I will probably ride a 20k TT, it would not surprise me if this is what my coach uses for my test.

Yes, it is expensive to have a PM and the associated head unit. That's the point. It's variably worth it depending on what you're doing.