IBike power meter thoughts?

[Jack Brunk]

Just put one on my Cervelo Soloist Superlight. I'm new to power training. What's your thoughts on the device?


Jack

[Z3c]

Jack,

I have got to tell you that I like the way you think and act(buy); I have been pondering one of these for some time. I look forward to hearing your thoughts and comments..

Scott

[toaster]

Not impressed.

Some of the reliability and repeatability depends on the solidness of the mounting and also of the amount of vibration, or lack of, from the road surface.

It's a great idea and introduces a cyclist to power training but seems like it will be problematic some of the time. I've seen how it measures power against the SRM and PowerTap in comparisons but I wonder what happens over a wide range of real world conditions.

Lastly, it is huge and doesn't look very good on the handlebars being so big, IMHO.


Power and heart rate monitors are tools and you still need a coach to make either work.

[zank]

From what I understand after talking to some coaches, it works resonably well for FTP and tempo intervals and below where you get into quasi steady state. It does not work well to record sprints. In sprint workouts, you are not looking at or using your PM anyway. It is only there to record your effort for review later. But it is nice to have the reliable and repeatable data that you get when doing sprints using an SRM or PT. I haven't heard how well it does for AT intervals (30 sec - 2 min) or VO2 Max intervals (3-8 minutes). It probably works well enough if the road surface doesn't change drastically.

I think one of two things will happen. You will either a) find training with a PM helps bring larger gains more efficiently and then want to upgrade to an SRM or b) find it novel but not change your training/riding habits and not need anything more accurate.

I agree with toaster about getting a coach. At the very, very least, pick up Allen and Coggan's book, Training and Racing with a Power Meter. I don't know whether or not the IBike is compatible with CyclingPeaks WKO+, but that software has made tracking my training and progress very easy. So I suggest looking into that as well.

Good luck! I am sure TT will chime in with some words of wisdom.

[jimcav]

when i was getting mine. I think argentius threw his away. i read several threads at rbr, and then the wattage forum at google. i did not want to pay for SRM, so got ergomo. really like it, also use cyling peaks software.
had them on 3 bikes for the price of one SRM pro. now have sold my ITA BB bikes so will be selling those ergomos and keeping my english BB version.
hope it works out for you. if nothing else, having a PM really helps you see how your perceived effort and cadence/gear plays into your performance.
Personally, i need to read more about the correct way to train with power--but have only been really trying it since late July. My AC separation in May sort of killed 2 months of training.

[Too Tall]

Yep, it uploads to Peaks software. Zank gave a good assessment of practical function. Bottom line, you get what you pay for. Our group was fortunate to have the inventor join us directly after he walked the early prototype around Interbike. We hammered on the unit and had a few beers...determined it works in a limited fashion for what we want to do. Might be a good call for someone who does lots of endurance riding? Not for an serious USCF type in my opinion. Stay tuned, there a two promising new Power Meters coming to market in the next yr. Don't hold out for a big price break...sad ain't it?

[zank]

TT, I don't mind paying if the technology is better. Are the new PMs in the SRM Pro range? Should I hold off on the SRM? Will I be able to use a Garmin 705? :banana:

[Too Tall]

Both of the pre-release PMs will prolly be in the same price range as ERGOMO. I still think that the orig. SRM is one of the best bargains dot period. When you consider that they rarely fail , getting the data is super easy and repairs are done by overnight mail to Colorado...just sayin....uh I mean ATMNSHO :cool: Unless I really missed the boat that new Garmin will receive ANT enabled PMs so it is not a PM. There has been some really cool work done over the last few yrs. to merge the cartographic data, fun stuff.

[zank]

Unless I really missed the boat that new Garmin will receive ANT enabled PMs so it is not a PM. There has been some really cool work done over the last few yrs. to merge the cartographic data, fun stuff.

You are correct. It is not a PM in and of itself, but it can receive data from ANT enabled PMs.

[J.Greene]

!

[ada@prorider.or]

What's your thoughts on the device?
Jack


it's a nice toy
nothing more :bike:

[MarinRider]

Jack,

Knowing your standard on things, you will probably not like the iBike. SRM remains the standard - consistent, easy to use, reliable, ect.

I really like the cannondale si Hollowcrank SRM units: light, stiff, super narrow q factor. You might not like Cannondale bikes, but the cannondale SRM cranks are worth "down-grading" your bike imo. I have a lead on a 54 cm Liquidgas team bike with record/SRM at a significant discount off MSRP if you are interested. PM me.

Otherwise, you can get Temple Cycles to build you a bike using the Cannondale BB standard.

Best.

[Jack Brunk]

it's a nice toy
nothing more :bike:
Cees,

Does it work as advertised? Is it somewhat accurate? Have you spent time playing with it? In your opinon does it come close to the SRM?

Thanks,

Jack

[jimcav]

spend some time searching roadbikereview or the google wattage forum. it is not a true power meter, but an estimator from all i have read on it. I went through the same decision process--wanted an SRM then saw the cost and went with Ergomo. Mine worked great, then a sensor went bad, GITA fixed it, not it works fine again. While waiting I picked up a spare on ebay--it also works fine. I find it very helpful tool to match effort and cadence to power, i like the altimeter function. I hear SRM is more accurate, but my ergomo seems very consistent unto itself, so feel i can readily judge my progress. I remember one of the Ibike gripes i read was that it estimates too many variables--so the number you get can be off. One thing Ergomo hsa shown me--no matter what I feel like, good, bad, hill, wind, etc--the power numbers are there--and sadly don't lie.
if most of your rides are on flat, windless terrain, the ibike may be a good estimator and give you good ride-to-ride feedback.

[ada@prorider.or]

Cees,

Does it work as advertised? Is it somewhat accurate? Have you spent time playing with it? In your opinon does it come close to the SRM?

Thanks,

Jack

simple test for ibike
put the bike on its handle bars
turn the wheel
look how the data change
that ´s ow you can see how it works
also if you start with 2 bottle full of water and empty it you got wrong date
well list goes on and on






its not accurate
its has bad software nowhere you can calc something accurate

its way of a srm

well most people use srm as a cycle computer ,hardly any one know how to use a power meter interped the date from it
its more used as look what i got.
if you ask some or they can calc there cda or devations of power they have no idea where you talk about so.
and lots of people do not even calibrate there srm right so...........
in that its a nice cyclo speedo meter

[1centaur]

"Does it work as advertised? Is it somewhat accurate?"

Yes, if your definition of "advertised" is the information you can glean from all the stuff jimcav mentioned, and yes, the online reviews that actually compare accuracy vs. the SRM are reflective of its accuracy - i.e., it's quite accurate and thus a real bargain as a power approximator. As beaten to death in this and every other forum over the last few months, if being within 10 watts of SRM power every moment of a ride is important to you, you're out of luck. If temporarily not knowing your power on a really bumpy section is important to you (a bizarre standard, IMO) then you are out of luck. No matter how many times actual users express satisfaction with a level of accuracy that has impressed various objective reviewers, others will express scorn and contempt for its imperfections. The bottom line is, the facts are well represented online after you have done some reading, but you'll have to wade through a lot of guffaws before you're done.

That said, it is more of a toy than the SRM; its software always seems a little bit "version 1.3" and I've had issues with it reading the signal when I stop for a few minutes and start up again. Ultimately, it did for me what I wanted, which was to tell me what kind of power I was putting out in various gears and in various terrains outside - my learning curve was very quick because its data was so consistent with what I learned from the Computrainer. After I knew what 400 outdoor watts felt like, and what average watts were for one of my 50 milers, there was not much point taking it along all the time just to see the same numbers because I wasn't about to ruin my rides with a structured power program. In your situation, as in mine, figuring out which bike to put it on was interesting and limiting - I would be happy to know casually what my watts were on any given ride or after a spontaneous surge but with the iBike I had to plan to ride that bike and do the coast down calibration. That kind of mild curiosity is not worth an SRM on every bike, though that would accomplish that goal.

BTW, follow the logic chain on the water bottle remark above - steel bikes that weigh 2 pounds more than CF bikes are just the same, the weight does not matter; the extra weight is just equal to a couple of water bottles, so who cares?; iBike's power reading will be different when your water bottles are empty vs. when they're full; that difference is meaningful; those 2 pounds are meaningful.

FWIW, the iBike says to enter a weight that reflects average water bottle weight over the course of the ride. OMG, that's so inaccurate, you'll never win the Tour!

[zank]

I think Cees' point about the bottles is not about the weight itself, but more about teh change in weight of the rider and bike during hte course of a ride. Since weight is an input into the iBike's calculations, the calcualted power will fluctuate depending on your rate of hydration, persperation and urination. But since the accuracy is low to begin with compared to an SRM, PT or Ergomo, it probably doesn't matter anyway.

I also agree with Cees that a lot of riders riding around on PMs are using it as a glorified cycle computer. I asked two guys on Sunday who both had PTs about their training. They both said they just do group rides most of the time and look at the data afterwards. They do very few power based workouts. What's the point?

[Simon Q]

I think Cees' point about the bottles is not about the weight itself, but more about teh change in weight of the rider and bike during hte course of a ride. Since weight is an input into the iBike's calculations, the calcualted power will fluctuate depending on your rate of hydration, persperation and urination. But since the accuracy is low to begin with compared to an SRM, PT or Ergomo, it probably doesn't matter anyway.

I also agree with Cees that a lot of riders riding around on PMs are using it as a glorified cycle computer. I asked two guys on Sunday who both had PTs about their training. They both said they just do group rides most of the time and look at the data afterwards. They do very few power based workouts. What's the point?

I may be off the mark here but to further Zank's last point it seems that unless you are going to use the PM to help with training or racing intensity zones any PM will effectively be a toy. To just see what you did after the ride is interesting but doesn't help heaps unless you have a structured program. With very limited training time I am by necesity quite stuctured with my riding and most workouts have planned intervals etc and as such I would love to have a PM, even an approximator, to provide feedback mid interval in addition to PE and HR. PM would be especially useful on undulating terrain or where you are riding in blustery conditions to ensure you are hiting the right intensity and to track progression over time for the same workout.

Anyway, thank for the thread and discussion as I am very interested in simple and cheaper PMs.

Ride magazine recently had a series where an exercise physiologist from the Australian Institute of Sport compared the performance of all the leading PMs including iBike. I will dig it out and see what was said.

And what about this one?

http://www.minoura.co.jp/flex-e.html

[Chris]

If that thing really works it is going to be bad azz.

[MarinRider]

I am not an expert by any means. However, I am sure that one can use PM effectively without knowing CDA, reynold's numbers, or how to solve Navier-Stokes (not possible in the classical sense BTW).

Here is a good example of PM usage posted by Andy H.:

http://www.scottthor.com/index.php?name=News&file=article&sid=213

In my experience, accuracy is critical if you want to train with a PM. A 5- minute-400-watts interval is (and feels) very different than a 5-minute-360-watts interval. If you just use one device, as long as that device is consistent and reliable from day-to-day, you can reasonably plan workouts round it. Consistency and reliablility are not my experince with Ergomo or Polar for doing interval workouts.

[1centaur]

cees' point was that weight=watts=relevance. My point was that so many say that minor weight differences do not matter, so do those few watts matter? It's inconsistent to say that weight does not matter on a bike and then complain about the iBike being inaccurate to that degree.

IMO, the iBike has been shown in multiple comparisons to be surprisingly accurate most of the time. You can do structured training around it if you wish, and you will gain most of the advantages of such structured training. Obsessing about a few watts difference vs. SRM in some but not all circumstances seems silly for MOST riders. Those complaining swear this is not the case for THEIR training purposes. The iBike is not for those people.

[Jack Brunk]

I took it on it's first ride today and it seemed to work very well. I used it in a variety of riding conditions and it was interesting to say the least. To bad it doesn't have a built in HR to run along with the numbers. I think I might get a couple of bike munts for my other bikes.

[myette10]

http://garmin.blogs.com/.shared/image.html?/photos/uncategorized/2007/08/29/edge705_2.jpg

should have got the wireless PT! damn!

[ada@prorider.or]

I took it on it's first ride today and it seemed to work very well.

well then it has served it goal
now only have to do is put it on each bike
download it on google and you can see 10 years what you did on what road
even make a video from it and attach it to the data

even better publish it on google so you can have kmz point for evry one to see

hence you then can even let calc your aerodynamic performance

or

just have fun on the bike and do not worry about numbers

[J.Greene]

I took it on it's first ride today and it seemed to work very well. I used it in a variety of riding conditions and it was interesting to say the least. To bad it doesn't have a built in HR to run along with the numbers. I think I might get a couple of bike munts for my other bikes.

Jack,

Ride this awhile. If your gonna get addicted to data, get addicted to the srm.

btw, what are you gonna do with the info gleaned?

JG

[nicrump]

I took it on it's first ride today and it seemed to work very well. I used it in a variety of riding conditions and it was interesting to say the least. To bad it doesn't have a built in HR to run along with the numbers. I think I might get a couple of bike munts for my other bikes.


any update here Jack?

[Jack Brunk]

any update here Jack?
No not really. Just doing some light base work on your awesome frame. I'll start using it seriously next month. My only real update is the Lew wheels are rock solid now. Ive got 1500 miles on the set and they are fast and stiff.

[Fixed]

well then it has served it goal
now only have to do is put it on each bike
download it on google and you can see 10 years what you did on what road
even make a video from it and attach it to the data

even better publish it on google so you can have kmz point for evry one to see

hence you then can even let calc your aerodynamic performance

or

just have fun on the bike and do not worry about numbers
i ride for fun i think we all do that (or most) i can't afford numbers... if i could i'd buy some numbers

[Climb01742]

jack, one other option for you might be to see if one of your fav wheel companies -- lew? -- would build you a rear wheel with a PT wireless hub. the way you move between bikes. SRM makes no sense. but a wireless PT wheel that you dig, that could be swapped between bikes, might be an option.

[Mud]

I took it on it's first ride today and it seemed to work very well. I used it in a variety of riding conditions and it was interesting to say the least. To bad it doesn't have a built in HR to run along with the numbers. I think I might get a couple of bike munts for my other bikes.

Not a believer in calculated stuff. This is one of my favorite rants. Any toy that calculates without a true measuring tool is still a toy. SRM, PowerTap, Computrainer actually measure.

[coopdog]

Not a believer in calculated stuff. This is one of my favorite rants. Any toy that calculates without a true measuring tool is still a toy. SRM, PowerTap, Computrainer actually measure.


And what do they actually measure that iBike does not? How is a strain guage any more "true" than an anemommeter?

[Mud]

And what do they actually measure that iBike does not? How is a strain guage any more "true" than an anemommeter?

I have seen all the stuff-PowerTap, SRM, IBike etc. It would seem that what is needed is consistancy under a wide variety of conditions. Things that have to calculate power rather than measure it are never going to be as accurate. A wind measuring device is still calculating and interpreting while others measure force at the crank or at the rear wheel.

I am not a scientist but I also think I have some common sense as to what to believe. I read my Garmin (or prior to that a Polar) and get these fantastic calorie readings. They are calculated on some formula that involves speed, HR, whatever. I wish it were true. Hagen Dazz here I come. :banana:

As I said, you can believe what you want.

[coopdog]

My point is that watts is a unit of power. A strain guage like in SRMs or PTs measures force. The ibike measures force too. For every action (such as the force on the crank meaured by SRM) there is an equal and opposite reaction (such as the incline, wind, etc measured by iBike). All powermeters extrapolate watts from a measurement of force. I'm not saying one is better than the other. I would agree that the SRMs/PTs seem to be a simpler path to calculating power.

We can also agree that consistecy is the key to powermeters. Consistency and accuracy are two different things.

[Squint]

iBike apologists like to argue semantics in that neither SRM or PT measure power either.

That argument can be sidestepped by considering how direct the measurement is rather whether it is direct or not.

Theoretically, you could measure power by measuring the change in the Earth's rotation due to a rider's pedaling action.

iBike works...in theory.

In theory, Communism works...in theory.

[Squint]

We can also agree that consistecy is the key to powermeters. Consistency and accuracy are two different things.

The myth of a cheap, inaccurate, yet precise powermeter is busted:

"Second, while accuracy and precision are in theory two different things, in reality they often are not, at least when it comes to electronic instrumentation. That is, a well-designed and well-manufactured product will tend to be both accurate and precise, whereas one that is poorly-designed and/or poorly-manufactured will tend to be neither."

(Andrew Coggan)

[Mud]

in drag racing. Engines were dyno'd, measurements taken but all that really matters is what gets to the ground. Watch a 10,000 hp "car" go up in smoke. The engine puts out the power, you get the readings but what does it mean?

I like the Computrainer because it measures at the rear wheel. PowerTap is the same more or less. There is another that measures at the BB but the position of the wire determines accuracy. We just keep moving the wire until the customer is happy. It is his gadget.

The other reason I like measurement at the rear wheel is the chain. The chain has 100 or so moving parts, more than anything else on the bike. Certainly there is power loss through the chain.

Again, I am not a scientist by any stretch but it is not logical that a meter that depends on being level, a riders weight and age, and other variables is going to be more accurate and consistant than something that measures regardless of the size, ability, etc, etc of the rider.

But then again, I thought the altitude readings on my Garmin were OK util I was set straight here. Maybe I am still wrong but it would be really tough to convince me. :crap:

[coopdog]

I didn't realize Andrew Coggan was the last word on physics. I've never heard of him. Nevertheless, there is a big differnce in accuracy and precision. As it relates to cycling, is it more important to compare your power results to those of others or yourself? I would say it is more important to compare your current effort against your former efforts thus making precision more important than accuracy. I don't care how many watts Lance pulled on Whatever Mountain (accuracy). What is important is how many I pulled on it last month (precision).

Back to my original point. You may hate the iBike. That's fine. I don't own one and don't want one. But the original poster, Mud I think it was, implied SRMs "measure" watts which is simply untrue. There are forces acting against you as you propel yourself down the road (ibike) and there is the force you generate to 'overcome' those forces (SRM).

Yes, I'll say it again. I agree. SRM's and PT's appear to be the more elegant and thus more precise solution.

Cheers. :beer:

[Squint]

I don't hate the iBike. I don't like what some people and iBike's marketing claim it can do (which are false claims). The fact is that it is neither accurate nor precise.

Theoretically, accuracy and precision can be completely unrelated. Theoretically, the iBike can work. Theoretically, a broken clock can be right.

But enough people have used the iBike in the real world to know that it doesn't live up to the hype.

[Mud]

Back to my original point. You may hate the iBike. That's fine. I don't own one and don't want one. But the original poster, Mud I think it was, implied SRMs "measure" watts which is simply untrue. There are forces acting against you as you propel yourself down the road (ibike) and there is the force you generate to 'overcome' those forces (SRM).

Yes, I'll say it again. I agree. SRM's and PT's appear to be the more elegant and thus more precise solution.

Cheers. :beer:[/QUOTE]

I just offered my 2 cents. Instead of watts maybe horsepower which we can convert to watts if that makes everyone happy. Again, think it through. Racers rely on stiffness of the frame to transmit all their energy into forward motion. All the energy is supposed to wind up at the rear wheel and on the ground. The more you get to the rear wheel the faster you go. On a car that is the most meaningful measure-HP at the rear wheel. A bike is no different.

I think we have killed this thread.

[ergott]

It would seem to make the most sense that if you want to know the power a rider puts out, you would want to measure that force closest to the power output which is the legs (both legs). As stated before, the best reason for knowing power is for training purposes. If you start measuring this force further and further from the rider's interface, accuracy is lost. Accuracy is always lost when other factors enter the equation such as weight, atm. pressure, and wind speed.

[nicrump]

eff it. a thread of pure conjecture.

i think i will risk $ on an ibike and take my buddy’s offer on a 60 day SRM loaner. run em simultaneously and see how the data stacks up after a month or two.

[Fat Robert]

eff it. a thread of pure conjecture.

i think i will risk $ on an ibike and take my buddy’s offer on a 60 day SRM loaner. run em simultaneously and see how the data stacks up after a month or two.


those crazy aussies at Ride magazine already did it, bro.

save yourself the dough and just have fun with a borrowed srm

[nicrump]

those crazy aussies at Ride magazine already did it, bro.

save yourself the dough and just have fun with a borrowed srm

link?

[Fat Robert]

i don't know if they have it online.

there's a hard copy in my bathroom, if you'd like...i could mail it to ya.

i played with an ibike and was impressed at what they were able to achieve, but not impressed with it as a good training tool. it gves you "ballpark" wattages and kjoules. if you are a recreational cyclist who is not doing structured training, its a neat adjunct to a cycle computer. it gives you a general idea of what you are doing.

the point of power-based training is to be able to look at differences as small as 10 watts, and make evaluations from accurate and precise data. the ibike doesn't do that for you. for the ibike, it makes no difference whether you did that 20-minute interval in the drops or on the tops, over gravel or on smooth pavement. it draws on what environmental data it collects, and your coast down calibration, to give you a "ballpark.

if "ballpark" is all you want, great. ibike gives you a 400 dollar toy to play with. however, if all you want is a "ballpark," i would question why you are using a powermeter to monitor "training" with anyway, because its not giving you data worthy of consideration.

put the 400 bucks towards a more accurate powermeter. or just ride for fun.

[nicrump]

http://forums.roadbikereview.com/showthread.php?t=75950

[Too Tall]

I'm so glad not to have a dog in this fight.

Anywho can't you blame this on Jack Brunk instead? It would be a more productive use of time, power and efficiencies ;)