61 replies to this topic Post Order

[Windbreaker]

Watched SC last night and was a bit surprised by the punt for the iBike power sensor. At R4,500 + R800 for the cadence sensor it is not that far off the real McCoy in terms of cost (PT for those not in the know ).

 

I am very sceptical after my experience with the Polar - this has even more variables to

a) measure accurately

b) handle in the algorithms correctly

 

Has anyone tried it? McClean reckons that he is using it with his SRM and the results are "quite good". He was careful not to state any figures though. He also said it a "thing of the future". Decoded, does that mean that it still doesn't work in the present?

 

[Spinnekop]

TCS have one or two on their bikes, busy testing it.....

I am sure Crux will give some details once the results are out......

 

 

[AndreZA]

Measuring the wind speed does not make sense. Atleast that's the way I understood it.

[domenic]

I think he meant power training is the thing for the future.

[shammy_rash]

look at the link below: video clip on ibike

http://www.worldcycling.tv/content/streams/viewClip.do?collectionContainsId=1051&videoClipId=784&collectionName=Advertisers

[bruce]

The underlying principle is sound i.e. the force that you produce is equal to the forces being applied to you in the opposite direction.  So to ride at 32 km/h you must apply the same force that the wind resistance is applying to you, and the gravitational force if you are on a gradient.

I believe the problem lies is accurately measuring the forces that are being applied to you.  From an iBike perspective, many of these forces are predicited and not actually measured.  Same as the Polar - using chain speed and vibration, it predicts the tencion on the chain.

Some of the problems that I have heard regarding the iBike:
1. Does not behave well on rough roads where there is significant vibration.  Apparently the accelerometer goes into oscillation and spikes.
2. There are questions about it's performance in bunch riding.  Being mounted on the handle bars, it is assuming the wind speed it is reading is what is being applied to your entire body.  In bunch riding your chest shoulders and head will be encountering more wind resistance than your handlebars.

Not being able to use it indoors is a big problem for me (contrary to Owens theory).  Power based training requires sessions to be ridden at specific power levels and durations.  This is quite hard to do outdoors.  THen if you only use your power meter on certain rides, you are compromising it's value.

[Cruxpearl]

I mailed Hunter Allen from CyclingPeaks.com, author of the Power Training Bible "Training and Racing with a Power Meter" and asked him what his opinion of the iBike Power Meter was...

His Reply:

I have had an iBike for about 5 months now. It's pretty neat, I must say.  It's not measuring Strain, like SRM,etc. but darn if it's not damn close to my other power meters.  I am impressed.  Only time that messes it up is when you do the 'coast down' on a smooth road, but then ride on a bumpy road. Then the watts are messed up.  They have released new firmware that addresses this, so supposedly they have fixed this issue. I don't know, as I haven't had the time to test it myself. 

If there is anyone that can give an informed opinion on Power Meters, it has to be Hunter...

[Windbreaker]

 

Bottom line - it has serious flaws. Too many variables to deal with. I'd be pleasantly surprised if the iBike turns out to be as accurate as the Polar even, in which case I'd hold out hope that Polar would be able to get theirs right too.

 

 

[Windbreaker]

Quote

I mailed Hunter Allen from CyclingPeaks.com, author of the Power Training Bible "Training and Racing with a Power Meter" and asked him what his opinion of the iBike Power Meter was...

His Reply:

I have had an iBike for about 5 months now. It's pretty neat, I must say.  It's not measuring Strain, like SRM,etc. but darn if it's not damn close to my other power meters.  I am impressed.  Only time that messes it up is when you do the 'coast down' on a smooth road, but then ride on a bumpy road. Then the watts are messed up.  They have released new firmware that addresses this, so supposedly they have fixed this issue. I don't know, as I haven't had the time to test it myself. 

If there is anyone that can give an informed opinion on Power Meters, it has to be Hunter...

 

Good going Crux. Ask him for the raw data.

[Token]

I would be nice if it had a heart rate read out too

[Cruxpearl]

Quote

Bottom line - it has serious flaws. Too many variables to deal with. I'd be pleasantly surprised if the iBike turns out to be as accurate as the Polar even. 

The PowerMeters that Hunter Allen was comparing it to, and found it "damn close to my other power meters." was actually SRM & PowerTap... not to bad for a flawed little thingy with too many variables to deal with...

[Gumpole]

You would also have to keep an identical position on the bike. ie drop into a more aero position, same power ... you speed up and the sensor says you are producing more power.

Never mind measuring 'road quality'. I reckon that taking your HR and then guestimating the power used will be no more innacurate.

 

But I'll wait for the experts to give their verdicts.

[Cruxpearl]

I would venture a huge guess and say:

"Hunter Allen is probably THE EXPERT on Power Training"????

[bruce]

Take a look at the following:

http://www.cyclingfo...om/t341477.html

http://www.cyclingfo...om/t290593.html

Various views on the topic.

Personally, I think it works, not quite are accurate as the big 3 devices, but then you get what you pay for.  It just doesn't work for me with the indoor problem.

[bruce]

Quote

I would venture a huge guess and say:

"Hunter Allen is probably THE EXPERT on Power Training"????

Hunter is the owner of the CyclingPeaks software company.  Andrew Coggan is more THE EXPERT on Power Training.  Hunter does know a thing or two though .

[Dr. Seuss]

really don't know as much as bruce / bikemax on the subject,  but i have been doing a fair amount of reading on powermeters as i want to be well informed before i put my money down.

i really cant see how the iBike can be equal to the ergomo / srm / powertap.  there is just way to many variables to consider. 

what happens when you go on a long downhill for example? 

your normal polar HR monitor will still register your HR as high because of your heartrate lag after the big climb,  the ergomo / srm / powertap should not register any power because you are not doing any pedaling so you are in true fact not doing any work,  the iBike will for sure register some impressive power as you are now going @ 80 - 90 km/h!

i think that with the iBike you will only be toying with the idea of power training,  but with the others you will be doing it seriously.