Why are power meters so bloody expensive???
Discussion
What is the justification for power meters costing more than a nice mid-range road bike? There don't seem to be any particularly expensive bits in them?
Just out of interest, would it be possible to calculate power from other data? For example, if I know my speed, cadence, angle of ascent, my weight and that of the bike, what else is missing? I suppose you'd need to find a way to estimate drag factors?
Just out of interest, would it be possible to calculate power from other data? For example, if I know my speed, cadence, angle of ascent, my weight and that of the bike, what else is missing? I suppose you'd need to find a way to estimate drag factors?
Kermit power said:
Just out of interest, would it be possible to calculate power from other data? For example, if I know my speed, cadence, angle of ascent, my weight and that of the bike, what else is missing? I suppose you'd need to find a way to estimate drag factors?
Yes, there are a few on the web and the biggest problem I found was obtaining values for drag factors. But again, someone else has sorted them out as well 
You don't need cadence, just weight/angle of ascent and drag from the bike, tyres and wind. As you'd expect, friction from the bike isn't very much it's your position & wind speed which are the big factors on the flat. The weight of you and the bike only come into it once you start climbing.
Here's one for example http://bikecalculator.com/
(and yes, if they were cheaper I'd have one as well. But I'd probably find it upsetting.....)
Get Karter said:
Bike 'computers' cost a fortune when they first came out in the late 80s. Now they give them away.
HRMs cost a fortune when they came out (early 90s?). Now the basic ones are dirt cheap.
Wait 5 or so years and power meters will do the same.
Yeah but power meters as got spensive scientifics innit, innit?HRMs cost a fortune when they came out (early 90s?). Now the basic ones are dirt cheap.
Wait 5 or so years and power meters will do the same.
Kermit power said:
What is the justification for power meters costing more than a nice mid-range road bike? There don't seem to be any particularly expensive bits in them?
Just out of interest, would it be possible to calculate power from other data? For example, if I know my speed, cadence, angle of ascent, my weight and that of the bike, what else is missing? I suppose you'd need to find a way to estimate drag factors?
There's a lot of R&D that goes into making sure that they are accurate 100% of the time. I guess making a power meter that worked for a couple of miles at a constant output might not be so tricky...Just out of interest, would it be possible to calculate power from other data? For example, if I know my speed, cadence, angle of ascent, my weight and that of the bike, what else is missing? I suppose you'd need to find a way to estimate drag factors?
There is an alternative: google iBike. But it is best called a power estimator, rather than a power meter. If you want to use a power meter properly (and you'll most likely need a coach to set you some specific exercises) you need to be able to measure your power output to within a few %. Otherwise there is zero value in a session in which you are trying to maintain 110% of your previous output for the same exercise. iBike isn't particularly accurate.
Garmin have a pedal/cleat based system due for release. Four figure purchase price. Brimm Brothers have been working on something similar for ages.
If you really want one, scour ebay, or better yet the classifieds at weightweenies or tritalk or slowtwitch. You have to make a decision at some point whether to go for a wheel based meter (Powertap) or a crank based system (SRM or Quarq). There are pros and cons to each.
Take a look as well at Power2Max. They are new to the market. Based in Germany and look to be SRM knock offs. Some of their models are relatively cheap, but you have to have a compatible crankset to go with them.
Bear in mind you will need a head unit (handlebar computer) to go with it. They aren't cheap. And some software to analyse your data. That isn't free either.
Greg66 said:
Bear in mind you will need a head unit (handlebar computer) to go with it. They aren't cheap. And some software to analyse your data. That isn't free either.
So long as it's ANT+ compatible, that's the one thing I already have. It's actually the empty "power" graph on the output from my Garmin Edge 800 that got me thinking I needed a power meter more than anything on the face of this planet! 
Kermit power said:
So long as it's ANT+ compatible, that's the one thing I already have. It's actually the empty "power" graph on the output from my Garmin Edge 800 that got me thinking I needed a power meter more than anything on the face of this planet!
Hehe. Those gaps can be awfully expensive...[quote=Greg66]
Garmin have a pedal/cleat based system due for release. Four figure purchase price. Brimm Brothers have been working on something similar for ages.
This is the system that i'm waiting for - apparently it is released summer next year. Suspect that it will be in the same price bracket as a crank based system so circa £1500.00, but will be much easier to swap between bikes.
Do i need it? Nope not at all as i'm nothing more than a weekend rider really, but that doesn't that stop me wanting it!
Garmin have a pedal/cleat based system due for release. Four figure purchase price. Brimm Brothers have been working on something similar for ages.
This is the system that i'm waiting for - apparently it is released summer next year. Suspect that it will be in the same price bracket as a crank based system so circa £1500.00, but will be much easier to swap between bikes.
Do i need it? Nope not at all as i'm nothing more than a weekend rider really, but that doesn't that stop me wanting it!
I would love a power meter mainly because I dont have one however the cost is just bonkers for me
There were reports that the Garmin/Metrigear product would come in at 600 pounds or so, however it has been publicised to arrive at 1400 so sod that
For 600 Id have been up for it
1400 isnt in my impulse purchase comfort zone
On the other hand as has been mentioned prices will surely come down in time
I do like the look of Power2max for 900 Euros but would like to hear a bit more about them first
cheers
Raoul Duke said:
This is the system that i'm waiting for - apparently it is released summer next year. Suspect that it will be in the same price bracket as a crank based system so circa £1500.00, but will be much easier to swap between bikes.
Do i need it? Nope not at all as i'm nothing more than a weekend rider really, but that doesn't that stop me wanting it!
Never really understood the easy swapping thing. I find removing pedals a complete PITA. Swapping a rear wheel is easiest, then (my) crankset, and last my pedals. Do i need it? Nope not at all as i'm nothing more than a weekend rider really, but that doesn't that stop me wanting it!
FWIW, I have a SRAM BB and SRAM/Quarq crankset and can move it across my bikes in under 2 mins easy.
I hate moving pedals. Have slammed my hand into the frame too many times.
Greg66 said:
Never really understood the easy swapping thing. I find removing pedals a complete PITA. Swapping a rear wheel is easiest, then (my) crankset, and last my pedals.
FWIW, I have a SRAM BB and SRAM/Quarq crankset and can move it across my bikes in under 2 mins easy.
I hate moving pedals. Have slammed my hand into the frame too many times.
One of my bikes looks like this...FWIW, I have a SRAM BB and SRAM/Quarq crankset and can move it across my bikes in under 2 mins easy.
I hate moving pedals. Have slammed my hand into the frame too many times.
the other looks like this...
Good luck swapping over the wheel or the crankset!
king difficult, that is. Gassing Station | Pedal Powered | Top of Page | What's New | My Stuff