Login required to started new threads

Login required to post replies

Power Meter question
Quote | Reply
I am training for my second long distance course, Challenge Roth. I have been spending more time on the indoor trainer and using virtual power for training and FTP tests. In the past I have not had much experience with training with power and my training plan has power ranges built in and I have really enjoyed this method the past few weeks.

I did my first outside ride this weekend and missed my power being available since I do not have a power meter...So I am in the market for a power meter but need some convincing.

I have my eye on 4iiii one sided crank arm which is a reasonable price (compared to some others), and I have done my research on one sided verse two sided.

I am wondering if this is a stretch for my training as I am definitely an amateur and can get by on not having the power. I have been riding for almost 4 years now.

But man I like that power when I train indoors, even if it is virtual.

Just need some encouragement to drop $300 on a power meter. How much more insightful is this tool for your bike riding tool kit ?

1-5 don't need it, just ride

5-10 don't be crazy, I love my power meter and it has changed my life

Thanks for the feedback.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
I started training with virtual power on a Kirt Kinetic Road Machine. I love it and made huge gains. I did my first 70.3 and wished I had power (I rode to HR and perceived effort). I bought a power meter before my fall half ironman, and loved racing with power as a guide. After a few years, I feel like a power meter is much more valuable for outdoor training than racing, but it is still valuable in races.

There are many debates in this forum of the value of single-sided PM versus a total power PM. You can search and read those. I would only get a single-sided PM that can be upgraded to dual-sided, because you may want a more accurate measure of power in the future.

The 4iiii is popular and pretty good. But... if you are not committed to a particular pedal, I highly recommend the Favero Assioma pedal-based PM. The single sided is $415, and you can upgrade to dual in the future. The major upside is that the product is awesome, and it is easy to move between bikes.

On your 1-10 scale, I would rate it an 8. I could race without it, but it would hurt me.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
10! Go for the 4iiii crank. Great product at great price!
Sam
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
IMO bad data is worse than no data, and one-sided PM's are just bad data. If you can only afford a one-sided PM I'd either wait until you can afford a dual-sided (or one that measures total power), or at least buy one that you can upgrade down the road. That said, to answer your question... 10 (but I'm a data geek). I can't imagine properly pacing a race without it. Of course, there are plenty of folks that do very well pacing by RPE or HR and are much faster than me. It all depends on your personality and how much you value hard data vs. feel.
Quote Reply
Re: Power Meter question [sgy] [ In reply to ]
Quote | Reply
sgy wrote:
10! Go for the 4iiii crank. Great product at great price!
Sam

^^^^^This!

I have a left-side 4iiii on one bike and a Stages on the other. The 4iiii is a better meter IMO.

Having power on your outdoor bike is not only helpful for training (for me not overdoing it on uphills and pushing the downhills a bit harder), it's super-helpful during an IM to be able to keep a steady power level and not overbike.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
Unless you are tied Speedplay pedals, get the single-sided Favero Assioma for about $400, and then upgrade to the dual for another $250 when you can. I bought the Assioma Duos last year as my third PM (after Quarq and Power 2 Max). The others were fine, but the Assiomas are truly amazing in that they just work every single time.

The rechargeable batteries last months, and I can swap them between bikes in a matter of seconds. They transmit in both BT and ant+. No issues with dropouts or water ingress through the battery door. No issues with accuracy on asymmetric crank spiders (new Shimano). In fact, the Assiomas are the one PM that you have a difficult time finding any negative comments/feedback about on the whole damn internet. Plus, at about $600 for the Assioma Duos, they are one of the least expensive dual-sided options available.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
I would rate between 8-10. I have 3 PM:
-Favero Assioma Uno on the Tri-/Roadbike
-4iiii left side on the MTB
-Power2Max Type S (dual side) on the cyclocross
I tested the Assioma together with the P2M at some rides and just recognised a max. difference of 3% (and that is close to the accuracy of the powermeter). So I think single side is good enough and there are huge gains by training/racing with powermeter.
Quote Reply
Re: Power Meter question [el gato] [ In reply to ]
Quote | Reply
el gato wrote:
IMO bad data is worse than no data, and one-sided PM's are just bad data. If you can only afford a one-sided PM I'd either wait until you can afford a dual-sided (or one that measures total power), or at least buy one that you can upgrade down the road. That said, to answer your question... 10 (but I'm a data geek). I can't imagine properly pacing a race without it. Of course, there are plenty of folks that do very well pacing by RPE or HR and are much faster than me. It all depends on your personality and how much you value hard data vs. feel.
I would agree with this.
Power figures extrapolated from single sided measurements are just estimates and may be very poor ones.
A true power meter must either measure both sides or the total. The likely error extrapolating from one leg is just too much of a compromise. I'd rather have HR and perception.

My suggestion would be something like a Power2max power meter which takes the total at the spider. Pretty easy to fit and not exorbitant if it's compatible with your existing cranks, which it may well be. This would be a lot more trustworthy than a single sided pedal or crank based meter. If you're only going to measure in one place, it should be a total power measurement. The downside is that it's not easily transferable between bikes like a pedal, but again, I'd rather have good data on one bike than bad data on two.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
I have had many power meters, started with Stages, then Quarq, then Favero Assioma

As others have said, Favero Assioma is by far the best as it just works, no faffing around, and the rechargable battery is brilliant.

I have one Favero Uno and a Duo. I know that I ride with a 50:50 balance, so the Uno is perfectly adequate. However, if you do not know what your balance is then a 2 sided power meter is a good idea

A power meter is one of the most useful pieces of equipment, and is probably as valuable to your average age grouper as it is for a pro. Through training, practice and experience, I know that if I race at 80-82% Intenisty Factor (IF) for a HIM or 74-76% IF for an IM, then I will be in good shape for the run, in fact in a race, on my cycle computer, I only look at 3s Power, IF, distance and time, I find everything else is irrelevent.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
What you need to do is figure out what is the safest average power for you to stay at for the entire ride and still have a nice run. Let's say it's 220 watts. One of the numbers to watch is average watts for you current lap. Set your lap to renew every 20 minutes. If your average watts for one lap is 222, then make your next one 218. Next, monitor your HR so that the number is appropriate for your watts. If your HR starts getting pretty high for the watts, then you're getting dehydrated. If it's low for the watts, something is wrong with your fueling.

The first few hours will feel way too easy, but you'll be glad at the end. Enjoy!

When you do a hilly or windy course, you'd have to adjust your watts per 20 minutes somewhat to take that into account.

----------------------------------------------------------
Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
Another vote for the 4iii! I have the one-sided setup on my bike. It works great for what it is. I think the one sided setups are great for triathlon. This is my first and only power meter on my bike, and it is doing great so far.

- Jordan

My Strava
Quote Reply
Re: Power Meter question [ZenTriBrett] [ In reply to ]
Quote | Reply
ZenTriBrett wrote:
When you do a hilly or windy course, you'd have to adjust your watts per 20 minutes somewhat to take that into account.

Why? Watts is watts. You'll be slower on a hilly or windy course, but why would that affect your target power?
Quote Reply
Re: Power Meter question [el gato] [ In reply to ]
Quote | Reply
I would say for long course tri like an 8 or a 9 in terms of value.
Yes there is some thinking to adjusting watts on a hilly or windy course, because that means you are likely to be out there longer. 100% agree that watts are watts, but if you are planning to ride for 5 hours at 220 watts, riding for 5.5 hours at 220 watts will likely result in a worse run. (Higher TSS)
I vote for Power2max. They just work all the time, and they just came out with there own branded crank in collaboration with Rotor that is very reasonably priced.
Quote Reply
Re: Power Meter question [ZenTriBrett] [ In reply to ]
Quote | Reply
ZenTriBrett wrote:
When you do a hilly or windy course, you'd have to adjust your watts per 20 minutes somewhat to take that into account.

Sorry, this is misinformation. A hill or a headwind does not affect your power output. On the other hand, heat, fatigue, injury, or illness might.
Quote Reply
Re: Power Meter question [RichardL] [ In reply to ]
Quote | Reply
RichardL wrote:
ZenTriBrett wrote:
When you do a hilly or windy course, you'd have to adjust your watts per 20 minutes somewhat to take that into account.

Sorry, this is misinformation. A hill or a headwind does not affect your power output. On the other hand, heat, fatigue, injury, or illness might.

I'm thinking that he meant on a hill or headwind you'll be going a little harder than you should (or your target) and on the next 20 min lap you should adjust your power output to bring the average power back down.
Last edited by: jaretj: Feb 25, 20 9:50
Quote Reply
Re: Power Meter question [jaretj] [ In reply to ]
Quote | Reply
So, ignoring wind for a moment and talking only about hills... BestBikeSplit demonstrates that a totally flat power output (VI=1.00) is not the fastest way to race a course. However, this brings into play many other variables, like what is a good target VI, what's a good target max power (and for how long) above the goal average power, etc. I use BestBikeSplit to simulate courses for upcoming races. I model a race in BBS and load the profile in Zwift and ride it, then see how I feel when running afterward. I'll usually go through 3-4 revisions of the race plan, playing with target AP, IF, VI, max. power, etc. I'll then use that power plan on race day. Having done this a few times now, I can say that if you haven't done this sort of analysis before race day and you think you're going to just "go a little harder on the hills and compensate on the downhills" you'll almost certainly overcook the bike. In that case I'd recommend just holding a flat average power as best as you can.
Last edited by: el gato: Feb 25, 20 8:22
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
Thank you everyone! I have some more research to do apparently because I have no idea what a "spider" is...

Got some good information on some other brands to check out and I learned that there are upgrade options if you go single sided at first.

Thanks! Very informative.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
Spider connects the crank arms to the chainrings. A removable spider would allow you to possibly add a PM to your current crank. (IE P2M Quarq or SRM) by changing your current spider for one with a PM built in.
Good luck!
Quote Reply
Re: Power Meter question [el gato] [ In reply to ]
Quote | Reply
el gato wrote:
ZenTriBrett wrote:

When you do a hilly or windy course, you'd have to adjust your watts per 20 minutes somewhat to take that into account.


Why? Watts is watts. You'll be slower on a hilly or windy course, but why would that affect your target power?


If it's safe to ride the same power on the entire descent, then, yes, hold steady.

If the descent is too steep and curvy to descend while maintaining your average target power without significant crash risk (like a 220w output on a 5% winding mountain descent), it might make sense to up the power a little on the climb since you will be doing less power on the descent.
Quote Reply
Re: Power Meter question [lightheir] [ In reply to ]
Quote | Reply
lightheir wrote:
el gato wrote:
ZenTriBrett wrote:

When you do a hilly or windy course, you'd have to adjust your watts per 20 minutes somewhat to take that into account.


Why? Watts is watts. You'll be slower on a hilly or windy course, but why would that affect your target power?


If it's safe to ride the same power on the entire descent, then, yes, hold steady.

If the descent is too steep and curvy to descend while maintaining your average target power without significant crash risk (like a 220w output on a 5% winding mountain descent), it might make sense to up the power a little on the climb since you will be doing less power on the descent.
In fact you should increase power on the climb and recover on the descent regardless. Likewise with headwind and tailwind. This is a more efficient use of the available resources. How much to push on the harder bits is a trickier question to answer.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
I will add that as helpful as powermeters are (particularly for indoor training!), don't forget that they are but one useful metric that in no way supplants the other usefuls ones, including RPE and even HR.

You can 'math out' your powermeter numbers all you want, but be prepared for race-day adjustments, often significant ones if you haven't recently raced the distance with the PM before (for real-life racing numbers.)

I learned this the hard way on my first two HIM outings with my PM.

The first course was particularly hilly and in retrospect had a significantly longer swim, and I was as well undertrained for the swim. Raced it at exactly my %FTP desired, not even off by a single watt on the average, off several repeated legit FTP tests prior to race, as well as good normalized/average power numbers from at least six prior 3 hr rides in the 2 months before race day. Thought I'd executed the bike well, took my nutrition, chased no fliers, then hit the run - which I was very well trained for, and my legs were dead. I had clearly overbiked it. Took me until mile 7 on the run before I got back to near 7 min/mile, which was super annoying.

Second one was Vineman in extreme 90F heat. I didn't really notice the heat much honestly on the bike, but in retrospect definitely should have not biked as aggressively as I did - I ate it on the run, finishing around the 50% AG mark, which is a huge underperformance to my typical run, even on a bad day.

The % numbers work well if you've tested in racelike conditions and also do NOT overswim (or be underprepared for the swim.)
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
I'm not even close to being a pro... so take it with a grain of salt.

After i started training with power i can't see myself going back. I've done some road races, TT's, OD and 70.3's with it.

For road racing it was pretty useless for me... maybe if you want to do some break-aways and know your 3-5 minute power it can be helpful... but I had enough trouble hanging on to the pack during the surges

For TT's and tri's it is an amazing tool... feels almost like cheating. If you know your numbers it is a great tool.

But the best part is it well help you with following a solid training schedule. Without a PM i don't think i would ever broke the 40km/hour with a 40k TT. Which might not be much for some of the folks here, but for me it was a huge milestone.

So i rate it a solid 9 out of 10.
Last edited by: IvarAlmere: Feb 26, 20 8:13
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
Amanda (that's you, right?),

PM is a great tool. That said, I raced pretty successfully for 30+ years before I got my first PM. The one thing that did was create a pretty good gauge of perceived exertion which is very valuable. In fact, I think the PM generation that has not developed perceived exertion are really limiting themselves. There is a fine balance between metrics and intuition in training and racing - you need to develop both.

Lots of folks I know "chase power" and I think that is dangerous. I tend to use power more as a feedback tool to confirm my perceived exertion and make sure my training is on track . . . I have found it particularly useful as I have aged and performance has declined. I also have a common psychological weakness in that I tend to way over bike climbs and end up burning matches; so, using the PM can can set in my mind an upper limit that I won't go over. I have found that very helpful.

Interestingly, last time i did Roth my PM died about 10 minutes into the bike. My perceived exertion was so good my bike split was exactly my pre-race target.

All that being said, I would not do serious training anymore without a 2 sided PM.

David
* Ironman for Life! (Blog) * IM Everyday Hero Video * Daggett Shuler Law *
Disclaimer: I have personal and professional relationships with many athletes, vendors, and organizations in the triathlon world.
Quote Reply
Re: Power Meter question [david] [ In reply to ]
Quote | Reply
Yes David, it is me!

Thanks for the input. I am inclined to not be too dependent on gadgets for that very reason. Anything can happen on race day....

I am not in a position to purchase a two-sided power meter... still contemplating what to do.

Thanks to all for your information and experience.
Quote Reply
Re: Power Meter question [AC_triwarrior] [ In reply to ]
Quote | Reply
One thing I found after going from using the estimated power to an actual power meter was that the estimated value was high.

It was a little bit of a let down when I started using the power meter. A few of the people I ride with had the same experience.
Quote Reply