Cycling Power Meters

tridying

looking for advise on power meters which is the best that dont cost a fortune i was looking at ibike..polar ... and the new vector on which is not on the market yet any advise please

Murph100

Forget the Polar, iBike etc. waste of money, you can pick up a second hand Powertap on ebay for the same cost.

Right now the only real players in town are SRM, Quarq and Powertap.

Metrigear Vector may or may not become a reality this year, so until its actually available, consider it vapourware, in fairness it sounds like the ideal solution.

Cheapest way to get a powermeter for the few months left in the year, is to rent a Powertap from these guys :

http://www.cyclepowermeters.com/

mloc123

The other problem with the metrigear is when it comes out you don't want to rush in and buy it, there will be teething issues. So in reality you are looking atlate 2011 or even 2012 before it is comparable to SRM, Powertap or Quarq.

If you have race wheels then crank based is your best option, if not then a powertap built in a wheel that could be used for training and racing. CRC have the Quarq for about €1700 at the moment and this is what I am looking at for next season.

IM0

tridying wrote: »

looking for advise on power meters which is the best that dont cost a fortune i was looking at ibike..polar ... and the new vector on which is not on the market yet any advise please

Ive had the Polar, and more recently the ibike, both are very accurate and consistent, just not as FOOL proof as the other well known ones. There are ways to use them which give propper CONSISTENT results...which is where its at

It might not work for you or others, but they CAN be nearly as good....in the right hands.

buzzingnoise

Have the ibike pro. Not great to be honest. It measures wind, incline, rolling resistance, cadence and road speed. From this it calculates Watts. That's not the same as measuring power directly from chain-sensor or bottom bracket like ergomo etc. The wind sensor port is open too and during the winter it let's water in. It is relatively consistent in the dry and on immaculate road surfaces but overall I couldn't really recommend it for Ireland tho.

Lumen

From what I've read from both Vector and Brim Brothers, pedal based powermeters are really hard to do.

Given the amount of R&D that's been sunk into them, I wouldn't expect them to be cheap.

I wouldn't be surprised if they end up costing around the same as the Quarq, but get marketed on the basis that you can swap them slightly more easily between any of your bikes.

The only way this stuff is going to end up cheap is if Shimano buy someone out and then bundle it with Di2. And then it still won't be cheap.

So for the time being it's still powertap, quarq and SRM for proven accuracy.

If I couldn't afford any of those I'd just use HR.

doozerie

This review of the SRM, Powertap, and Polar has a date of 2003 on it but with a "last updated" date of 2010. It's worth a read to get one person's perspective on how they compare and he goes into some detail on their respective strengths and weaknesses. I've not used a power meter but found the review informative.

IM0

doozerie wrote: »

This review of the SRM, Powertap, and Polar has a date of 2003 on it but with a "last updated" date of 2010.

+1 I saw this at some stage, cant remember if it was before or after buying the polar, I think after, but with what I got out of it I built on that and found where the strengths and weakness' are with it. I even went on to make my own gear chart based on what it was saying or how I started to think of why it worked and how can I get the most out of it.

Be sure in the right gear, it WILL be as accurate as the Powertap or SRM even, once you know how to use it

I also went on to check it against analyticcycling and it all stacked up just nicely, and didnt need one in each rear wheel like PT. If you already have the Polar HRM* its a bargain, if not just good value

*when I got it it was a wrist hrm with the S700 series of monitors as an option, now its still a Hrm but bike mounted like a computer and is a cleaner instal and maintenance.

Same goes for the ibike Pro, have one of them too, they work nicely again if you can get it to work for you

Ryaner

I liked my powertap so much, I went and bought two! Great training tool and highly recommended.
But it is a hard decision when you have multiple bikes. Currently I've only 2 (road) bikes and when I get my 3rd one, the wheels will be swapping between the different bikes. If you were someone who liked having skinny mountain wheels AND aero wheels for the flats, a crank based meter is probably going to be cheaper.

amjon.

I'd say second hand powetap or SRM from ebay is the way to go. You can pick up SRM's from about 700-800 or Powertaps from about 500

http://cgi.ebay.co.uk/2010-CycleOps-Power-Powertap-Comp-32H-Shimano-/130410872746?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item1e5d17ffaa#ht_3589wt_770

amjon.

me@ucd wrote: »

+1 I saw this at some stage, cant remember if it was before or after buying the polar, I think after, but with what I got out of it I built on that and found where the strengths and weakness' are with it. I even went on to make my own gear chart based on what it was saying or how I started to think of why it worked and how can I get the most out of it.

Be sure in the right gear, it WILL be as accurate as the Powertap or SRM even, once you know how to use it

I also went on to check it against analyticcycling and it all stacked up just nicely, and didnt need one in each rear wheel like PT. If you already have the Polar HRM* its a bargain, if not just good value

*when I got it it was a wrist hrm with the S700 series of monitors as an option, now its still a Hrm but bike mounted like a computer and is a cleaner instal and maintenance.

Same goes for the ibike Pro, have one of them too, they work nicely again if you can get it to work for you

Seeing as this is Ireland there is a good chance you'll be wanting to use your power meter on the turbo/rollers over the winter. You can forget that if you buy one of these. Would be interesting though to go on a spin with ones of these along with a Powertap and check out the discrepancy.

learn

Murph100 wrote: »

Forget the Polar, iBike etc. waste of money, you can pick up a second hand Powertap on ebay for the same cost.

Right now the only real players in town are SRM, Quarq and Powertap.

Metrigear Vector may or may not become a reality this year, so until its actually available, consider it vapourware, in fairness it sounds like the ideal solution.

The ideal solution for what? How will it improve a rider's cycling beyond that of the best powermeters mentioned above.

Lumen

learn wrote: »

The ideal solution for what? How will it improve a rider's cycling beyond that of the best powermeters mentioned above.

Maximum compatibility. There is no current single system which suits all bikes, drivetrains and wheels.

ktz84

Lumen wrote: »

Maximum compatibility. There is no current single system which suits all bikes, drivetrains and wheels.

And there still will not be as I can't use certain pedal systems because I can't unclip outwards. Yeah more compatibility but not maximum

tunney

learn wrote: »

The ideal solution for what? How will it improve a rider's cycling beyond that of the best powermeters mentioned above.

Everything. Per second power readings the WHOLE pedal stroke. Not sure 4-8 samples per stroke ala SRM and Quarg.

And its not vapourware - its the look/polar power meter being released at Interbike this year.

tunney

ktz84 wrote: »

And there still will not be as I can't use certain pedal systems because I can't unclip outwards. Yeah more compatibility but not maximum

Thats more a case of YOUR compatibility. Not that of the PM

billy.fish

amjon. wrote: »

Seeing as this is Ireland there is a good chance you'll be wanting to use your power meter on the turbo/rollers over the winter. You can forget that if you buy one of these. Would be interesting though to go on a spin with ones of these along with a Powertap and check out the discrepancy.

Its a consistant 9%

Many studies done on it. The polar is fine, just not for turbo or MTB.

tunney

billy.fish wrote: »

Its a consistant 9%

Many studies done on it. The polar is fine, just not for turbo or MTB.

And what about the restriction in terms of chainline?
What about moving bikes?
What about the fact that the head units cannot be used for power without HR?

billy.fish

tunney wrote: »

And what about the restriction in terms of chainline?
What about moving bikes?
What about the fact that the head units cannot be used for power without HR?

No restriction from chain line, once it crosses the sensor its fine.
Its not designed to be moved same as 95% of SRMs
Its designed for one head unit same as your SRM, and you can use it without HR.

Don't be stupid Tunney.

The question was about consistency. If you want to get finniky, its more consistent than an SRM that was kept in a nice warm hous, zero'd e and then taken out for a spin in the middle of January in the cold. #sarcasm

Cause we all know most people leave there SRM/Powertap/Quarq out side for 40mins to make sure the strain gauges get to the same temp as ambient temp for riding in. #sarcasm

Lumen

tunney wrote: »

Everything. Per second power readings the WHOLE pedal stroke. Not sure 4-8 samples per stroke ala SRM and Quarg.

It's complicated though. What is being measured - torque or productive torque?

Ideally you want three power meters, one in the hub and one in each pedal. Then you can produce efficiency numbers in the head unit.

That would be cool.

Got any more info on the polar/look solution?

ktz84

tunney wrote: »

Thats more a case of YOUR compatibility. Not that of the PM

And I'm not an integral part of the power generating process and there was me thinking I was the most important

When you only generate 240 watts over an hour just getting one that would lie. Though the powertap I have has died 3 times already so perhaps it's just not used to such patheticness

Lumen

billy.fish wrote: »

Cause we all know most people leave there SRM/Powertap/Quarq out side for 40mins to make sure the strain gauges get to the same temp as ambient temp for riding in. #sarcasm

Calibration is easy with the Quarq. You do a manual calibration at the start of the ride, then pedal backwards a few times if conditions change.

Are you arguing that an inaccurate power meter is as good as a badly-calibrated accurate power meter?

billy.fish

ktz84 wrote: »

And I'm not an integral part of the power generating process and there was me thinking I was the most important

When you only generate 240 watts over an hour just getting one that would lie. Though the powertap I have has died 3 times already so perhaps it's just not used to such patheticness

I'm hoping thats an average value...cause if you can only produce 240W over a 60 minute period as an absolute value..then yes..yes you are pathetic

billy.fish

Lumen wrote: »

Calibration is easy with the Quarq. You do a manual calibration at the start of the ride, then pedal backwards a few times if conditions change.

Are you arguing that an inaccurate power meter is as good as a badly-calibrated accurate power meter?

Where did i say inaccurate? Variability is the difference between inaccuracy and accuracy.

The polar is CONSISTENTLY off compared to another PM. So it always reads higher/lower.

So yes, i would say that a consistent error is better than an error that will change depending on changes in ambient temp.

I however am one of those anal people who will leave my bike outdoors for 40mins before i go for a ride so that my PM is correct, as is Tunney!

tunney

billy.fish wrote: »

No restriction from chain line, once it crosses the sensor its fine.

I've read on wattage that there are issues with certain chainline setups.

billy.fish wrote: »

Its not designed to be moved same as 95% of SRMs
Its designed for one head unit same as your SRM, and you can use it without HR.

Again on wattage but I bow to your nerdiness

billy.fish wrote: »

Don't be stupid Tunney.

I thought you knew me better than to say something like that? I can't help it

billy.fish wrote: »

The question was about consistency. If you want to get finniky, its more consistent than an SRM that was kept in a nice warm hous, zero'd e and then taken out for a spin in the middle of January in the cold. #sarcasm

Why would anyone do that though? Oh wait..........

billy.fish wrote: »

Cause we all know most people leave there SRM/Powertap/Quarq out side for 40mins to make sure the strain gauges get to the same temp as ambient temp for riding in. #sarcasm

I do. well 30.

Lumen wrote: »

It's complicated though. What is being measured - torque or productive torque?

Ideally you want three power meters, one in the hub and one in each pedal. Then you can produce efficiency numbers in the head unit.

That would be cool.

Alot of real estate required.

Lumen wrote: »

Got any more info on the polar/look solution?

Fraid not

ktz84

billy.fish wrote: »

I'm hoping thats an average value...cause if you can only produce 240W over a 60 minute period as an absolute value..then yes..yes you are pathetic

It's my average over the hour, IOW my FTP and it's still pathetic. Better than it was in February when I started at 195 watts if you could even imagine how pathetic that was. I'd have grannys passing me at will

billy.fish

tunney wrote: »

Alot of real estate required.
Fraid not

That PT looks familiar.....oh wait its mine

billy.fish

ktz84 wrote: »

It's my average over the hour, IOW my FTP and it's still pathetic. Better than it was in February when I started at 195 watts if you could even imagine how pathetic that was. I'd have grannys passing me at will

All about power to weight. W/kg. Pure average wattage not _that_ important

50kg guy doing 240W = 4.8w.kg-1
90kg guy doing 310W = 3.4W.kg-1

I'd rather be the tup guy...unless it was windy....or flat

tunney

billy.fish wrote: »

All about power to weight. W/kg. Pure average wattage not _that_ important

50kg guy doing 240W = 4.8w.kg-1
90kg guy doing 310W = 3.4W.kg-1

I'd rather be the tup guy...unless it was windy....or flat

What about someone like yourself?
90kg guy doing 240W = sloW.kg-1

billy.fish

tunney wrote: »

What about someone like yourself?
90kg guy doing 240W = sloW.kg-1

Ahh Tummey San, how you jest

82kg at 310W FTP at the moment (327W np for 20mins)

So 3.7W.kg-1. Totally agree i'm off pace at the moment. But then again i have been eating allot of cake so off my normal 77kg race weight (4w.kg-1).

Its ok, i can take my absolute Vo2 and wave it in your face little lung man. Not that absolute vo2 correlates to events much over 20mins....but we wont talk about that now will we....

*flicks through Tunneys numbers* I could post these anywhere you know Where is BC's email at.....

mloc123

billy.fish wrote: »

Ahh Tummey San, how you jest

82kg at 310W FTP at the moment (327W np for 20mins)

So 3.7W.kg-1. Totally agree i'm off pace at the moment. But then again i have been eating allot of cake so off my normal 77kg race weight (4w.kg-1).

Its ok, i can take my absolute Vo2 and wave it in your face little lung man. Not that absolute vo2 correlates to events much over 20mins....but we wont talk about that now will we....

*flicks through Tunneys numbers* I could post these anywhere you know Where is BC's email at.....

Lads, get a room

tunney

billy.fish wrote: »

Ahh Tummey San, how you jest

82kg at 310W FTP at the moment (327W np for 20mins)

You sure you calibrated it?

billy.fish wrote: »

So 3.7W.kg-1. Totally agree i'm off pace at the moment. But then again i have been eating allot of cake so off my normal 77kg race weight (4w.kg-1).

Whats that - your right leg?

billy.fish wrote: »

Its ok, i can take my absolute Vo2 and wave it in your face little lung man. Not that absolute vo2 correlates to events much over 20mins....but we wont talk about that now will we....

Wow - if only you'd ever beaten me. Or had a faster bike split Or out drank me.

billy.fish wrote: »

*flicks through Tunneys numbers* I could post these anywhere you know Where is BC's email at.....

They're *last* years numbers. Divide by 2 for this year

Lumen

billy.fish wrote: »

Tummey

:rofl:

Isn't Austria the IM for fatties? The climbers do France.

tunney

Lumen wrote: »

:rofl:

Isn't Austria the IM for fatties? The climbers do France.

Funny but not original. Credit goes to Peter Kerns for the name "Dave Tummy". If I ever meet him and he calls me "Dave Tunney" I know I'm at racing weight.

IM Austria is fine for fatties as long as they put a compact and a 27 on.

ktz84

billy.fish wrote: »

All about power to weight. W/kg. Pure average wattage not _that_ important

50kg guy doing 240W = 4.8w.kg-1
90kg guy doing 310W = 3.4W.kg-1

I'd rather be the tup guy...unless it was windy....or flat

I'm worse than both those guys

74kg. 3.2w/kg and where I ride it's all about w/kg as there is nothing but hills

billy.fish

mloc123 wrote: »

Lads, get a room

We did but there was an unfortunate indecent with a body fat callipers that we don't talk about any more....

Diarmuid

funniest 410 thread in a while