Any Cruzbikers using Newton Power Meter?

[LarryOz]

I am in the market for a power meter.
I have read many reviews (there are sooooo many out there).
From my understanding, the Newton takes a whole different approach to measuring power.

From one review, I think this sums up the difference: ?In comparison to the more familiar direct-force power meters (DFPM) such as Powertap, Quarq and SRM, the iBike calculates power using known physical and environmental variables. These include mass (rider + bike + accessories), speed of the object (rider), wind speed, rolling resistance, gradient and the drag co-efficient of the rider. Add all of these together into the correct formula and you get power which, in this case, is the amount of energy needed to overcome the forces mentioned above.

the link, if you are interested in the whole thing:
?http://cyclingtips.com.au/2013/09/ibike-newton-power-meter-review/

Anyway, the review is almost a year old now, and I have not found a newer one yet.
I also called the folks at iBike, and there where hesitant to tell me whether the Newton would work or the sensors could even be mounted on the Crizbike. One thing they mentioned is that they thought the unit needed to mounted horizontally and that they where not sure it would work correctly mounted vertically (which would be required to see the display when riding a Silvio or Vendetta)

I only saw one other post (on Cruzbike) that seemed to mention the Newton device (back in Jan I think), which mentioned that Jim and Maria has secured one but have not tried it yet? (Jim, Maria - any test feedback?).

Thanks in advance,
Larry

 

[snilard]

I haven't any experience with

I haven't any experience with any power meter. But I would not trust power meter that uses indirect measurement. Especially on recumbent.
Air drag coefficient is different on recumbent. Newton is designed to measure direct air flow unaffected by any obstacles. But if You put it on Cruzbikes handlebar air flow will be affected by frame and also by your moving legs.
Weight is main power consumer on uphills. Imagine some really long ride. You are carrying something like 3l of water. Before lunch you are out of watter and really hungry. So you go to pub, eat big lunch drink same lemonade and refill your empty bottles. Now you are 4 kg heavier than before lunch.
Or you are on ride in some really tight cycling clothes. It start to rain and you dress some not so tight jacket. Change in aero drag will be really significant.
Some features of Newton seem really good but it is not guaranteed that it will work correctly on Cruzbike.

 

[LarryOz]

all very good points

Thanks for the feedback!
For the Newton, they (
ibike) do have a remotely mounted wind sensor that will help get the frame of the Cruzbike bike out of the equation.
All your other points are valid about taking on more weight, other parameters changing, etc.

I think for me, one of the main reasons for getting a power meter would be to be able to test different components in as static as environment as possible.
For instance different tires, or even wheel sets, or helmets:
Then,
Ride a route keeping as many variables constant as possible (clothing, water on board, tools, heart rate during ride, cadence if possible, etc). Then switch the component you want to test (tires) and attempt to repeat the same route. This might help identify which components are more aero (or efficient) than others.
I think the other main use would be during longer training rides and during events, where you would like to keep an eye on your power output over a long duration, to make sure you do not over do it and burn out. And I think for the most part, you can do this with a heart monitor once you know you levels and are comfortable with them.

I'm still not ready to drop $700 or more on any power meter at this point unless I am sure it would really help me.
I would almost rather save my money to upgrade to a Vendetta!

 

[snilard]

For component testing, this

For component testing, this power meter is unusable. It estimates your power output from entered (or company measured) aero drag and tires rolling resistance. So you have to know this coefficients at first and than it will show your power. But you cannot measure these coefficients. You have to use real power meter for comparison of components.

I also thing that it is also not good for long rides where a lot of things can change (tire pressure, clothes, weight). I use heart rate monitor for this purposes. It is not perfect (my HR is higher at morning and also after cafe) but it's much cheaper.

 

[LarryOz]

Thanks for all the insight Bob

All I need now is unlimited time and money! - and energy!
...
I actually purchased a PowerCal heart rate monitor about a month ago. I am using mapmyride primarily on my Android phone, and for some reason (probably my inability to totally understand how to work or set it up), I could not seem to get the power and heart rate stuff to work simultaneously. The place that I purchased the unit was not much help either. Since you have one, what head unit do you use to collect the data?

For me, I think I have pretty much narrowed down a sweet spot of my heart rate of 125-135 (or around there), that I feel I can maintain for a significant amount of time (for now - longest is 8 hours), assuming of course that I feed the engine. What I would like, and know would be interesting data is to be able to see comparisons between my heart rate over a certain fixed course and my power output. Of course hoping that with the right training that the power output would increase over time given a fixed heart rate.

You also mentioned the book: Training with Power. I have tried to google it, but do not see a book by that exact name. Who is the author?

Wow, so Gary thinks I mash the pedals. I thought I was always a spinner! haha. I can't really mash them too much, as I had major reconstructive surgery on my left knee 30 years ago followed up by a couple of minor surgeries later on. (I used to be a runner, but after that I tool up cycling because of the knee pain), so spinning is the only way for me really!
?Speaking of Gary - I am so fortunate to live so close to someone so knowledgeable about bicycles and how stuff works, and now of course Cruzbike expert! (Plus the owner of one of the coolest Vendetta's!) Last night he helped me get my FD working again after 3 bike shops told me that it was toast! Hopefully later this week we are going to install your 100mm chainstay extension and fix my BB binding issue (If you can believe it, it will hardly spin one rotation on its own with a good push!)

P.S. When you get a free long weekend, come down here and ride the mountains with Gary and Larry!

 

[ratz]

Use.....

Ok for a head unit recording program I'm partial to Wahoo's Fitness App. It supports just about every sensor on the market; and it uploads to all the major services. That gets you service agnostic setup. Cyclemeter is better but there are millions of settings in that program; fiddle factor is too high for me, because I'd HAVE to use them. The powercal presents as both an ANT+ Heart Rate monitor and a PowerMeter; you have to connect both.

If you are doing power training you'll want a premium subscription to one of Strava, Ride with GPS, or Training Peaks. Strava has the most polish and the social part, the ride planning and training is coming along. Ride with GPS is technically better and deeper, the interface is cluttered but it's improving all the time. I sometimes think the recumbent community should make a mass migration to RWGPS and take our social part with us. I might draft a few people to give that ago. Training peaks excels at planing your training and nutrition and analyzing your results. Their old version has a cluggy interface and the beta interface, is ummmm weird. But for structured training it's the best. You can hire a coach on TP that will a be able to work with you in the software and monitor you progress and set your plans.

Sorry about the book. It's the bible; here's the link
http://www.amazon.com/Training-Racing-Power-Meter-Hunter/dp/1934030554/ref=pd_bxgy_b_img_y

?Warning, it's basically a text book; everyone I know that's read it had to read it twice to fully put it all together. Once you get it; it's not hard.

Eric gets full credit for the StagePower meter lead. I was just starting to get into power when I crashed years back; and The stages made it much more cost effective to get back into it. Warning though if you go with Stages they custom make them; and it takes about 6 weeks to arrive if they are low on the model you want. I wanted a 165mm Rival and it took 8 weeks.

 

[ratz]

I looked at ti

I've watched the newton for a while. It needs un-obstructed air; just really no place on the Vendetta and Silvio or any other recumbent for that matter that seemed like a good place to mount it even with the remote sensor. Being a math nerd I think it's a cool product; but not for me.

For the money; the StagesPower Meter or Vector Pedals are you best bet. Stages firmware in now darn impressive and the units are very accurate if you don't care about things like left and right contribution. You can move them between bikes quickly; and for a non pro-training they provide a lot of data.

If you only care about 5minute average and above; then the PowerCal heart rate monitor is a great intro to training with power and it's 99$; that lessor solution less you compare rides after the fact and remove the wind and road conditions from your comparison; it's of limited use while you ride because it reads spikey and high. To use it real time; you need to run it side by side with a normal power meter and learn how it reads by comparison. I can use mine now and have a fairly good idea what's going on; but it's still not the same.

Now Larry from what Gary says; I'm pretty sure your power meter will have one steady reading... "Ouch, don't pedal so hard"


Now all of that said; if you aren't going to use RWGPS, Strava or TrainingPeaks. And you are not going to read the book Training with Power, then save your money and buy better wheels. Power meters require a long term commitment; lots of historical data -or- execution of specific test rides in order to get the data you need to use them. The only FREE info they give you is FORM/FATIGUE moitoring very useful; but that's expensive if that's all you use. They are a multiyear awesome tool, you don't just throw them on the bike and go. My standard recommendation is put it on the bike and ride for a month; gather the data; and don't even look at it; While that's happening read the book. After a month you'll have the bare minimum for going forward.

All this is also enhance with the new power trainers for off season. The Wahoo being the current king; with power base ride replays.... I'm sure it's only going to get better.

 

[snilard]

I use Cyclemeter on my iPhone

I use Cyclemeter on my iPhone for monitoring all my rides. If just want to record my HR, I am using Polar H7 Bluetooth smart HR strap and record HR to Cyclemeter and Polar Flow in iPhone. When I am for HR training or for log ride with HR limit I am using Polar RS800CX wrist unit and some Polar HR strap. RS800 is much better than iPhone for limiting HR. It can beep when you are out of limits and you can just watch display. On iPhone I rode with screen off, It can talk to you but is has some delay and turning screen on for each limit break drains battery a lot.

 

[Eric Winn]

I have the Joe Friel

I have the Joe Friel book.

-Eric

 

[ratz]

How did ...

How did I miss that one; I have a the 2nd edition of his training guide, dead tree version. How's that one eric; easy to read?

 

[Eric Winn]

Yup, Joe Friel's Power Meter

Yup, Joe Friel's Power Meter Handbook seems to be pretty decent. I need to read it again and start following the advice. I've been in "just ride with the pm" mode to see what kind of data I get so I can understand the book better.

That Amazon link has the click to view content where you can see enough to get a good idea what the book is like.

I bought this one based on seeing it referenced in some BROL posts.

One of Friel's blog posts about workout nutrition also came up that I found interesting. Here is another good one: Quick Guide to Training With Heart Rate, Power and Pace

-Eric