Which power-meter?

Hi,

I am considering getting a power meter, so I am evaluating my options.
I have made a list with what the pros and cons are for me for the
different ones I am aware of. They are all expensive, so I don't list
that as a con for each one.

PowerTap
pros: a few models in different price ranges.
cons: I'd like to use for trainig and racing, so 2 hubs would be
expensive.

SRM
pros: allows any wheel
cons: I like my 195mm cranks, the longest SRM is 180mm.

Polar
pros: bike spec independant, altitude measurement.
cons: lots of wires, fiddly install, can't calibrate by standing on
pedal, silly watch type head unit (why isn't it shaped like a bike
computer?)

So what should I get? I am leaning toward the Polar despite it's issues
for the transportability.

Suggestions?

Joseph

wrote:

PowerTap
pros: a few models in different price ranges.
cons: I'd like to use for trainig and racing, so 2 hubs would be
expensive.

Why not one PowerTap wheel for both, and a normal wheel as a backup?

Chalo

Joseph wrote -

I am considering getting a power meter, so I am evaluating my options.

You could also consider the ergomo bottom bracket measuring device - see
http://www.bicyclepowermeters.com/

My lbs guy told me -

1. The ergomo only measures power on one crank and interpolates what the
power is on the other - the SRM 4 way system is more accurate in that
regard.
2. After evaluating all the available power measurement systems the body
responsible for training cyclists in New Zealand chose SRM - your budget may
vary.
3. For a stationary ergo, you can get a much simpler and cheaper measurement
of relative levels of power by recording cadence and resistance levels and
watching if you can improve on either or both over time. If you were
mathematically inclined you could probably calcualte the watts being
produced in varying gears at varying cadences if you are into absolutes as
opposed to relativities.
4. Likely that power sensors will evenutally be built into crankets over
time ("The Next Big Must Have Thing") if they can get round the SRM patent
or licence it cost effectively.
5. You may want to check how difficult the accompanying software is to use
or interpret - the native powertap software is not so great - suggest look
at something like http://www.cyclingpeakssoftware.com/index.html
6 You see a LOT of secondhand polar power measuring kits for sale in ebay
etc - suspect they may not be universally loved.

best, Andrew

wrote:
I am considering getting a power meter

Might want to check this out:
http://biketechreview.com/archive/pm_review.htm

Andrew Price wrote:
Joseph wrote -

I am considering getting a power meter, so I am evaluating my options.

You could also consider the ergomo bottom bracket measuring device - see
http://www.bicyclepowermeters.com/

That looks pretty nice. Suits my desire for equipment independence.

My lbs guy told me -

1. The ergomo only measures power on one crank and interpolates what the
power is on the other - the SRM 4 way system is more accurate in that
regard.

Do you know how it interpolates? Does it just guess?

2. After evaluating all the available power measurement systems the body
responsible for training cyclists in New Zealand chose SRM - your budget may
vary.

If I were happy with cranks =180mm I'd go for the SRM too, I think.

3. For a stationary ergo, you can get a much simpler and cheaper measurement
of relative levels of power by recording cadence and resistance levels and
watching if you can improve on either or both over time. If you were
mathematically inclined you could probably calcualte the watts being
produced in varying gears at varying cadences if you are into absolutes as
opposed to relativities.

I am most interested in maintaining a given output while riding.
Testing on a resistance trainer can be fun, but it's not really what I
am looking for.

4. Likely that power sensors will evenutally be built into crankets over
time ("The Next Big Must Have Thing") if they can get round the SRM patent
or licence it cost effectively.
5. You may want to check how difficult the accompanying software is to use
or interpret - the native powertap software is not so great - suggest look
at something like http://www.cyclingpeakssoftware.com/index.html
6 You see a LOT of secondhand polar power measuring kits for sale in ebay
etc - suspect they may not be universally loved.

This is true. I think the finicky-ness of the Polar is too much for me.
The whole issue of variation from gear to gear sounds like a problem I
don't want to deal with.

Thanks for the tip about the Ergomo. Now I just need to find an extra
$600...

Joseph

Chalo wrote:
wrote:

PowerTap
pros: a few models in different price ranges.
cons: I'd like to use for trainig and racing, so 2 hubs would be
expensive.

Why not one PowerTap wheel for both, and a normal wheel as a backup?

Chalo

That's an idea. I am starting to lean that way. The power measurment is
mostly for racing and TT's. I'm not really sure how I would incorporate
power training into my program anyway, other than occasional spot
checks and position/equipment testing which could be done on race
wheels.

I wish the PowerTap had an altimeter!

Joseph

wrote:
Andrew Price wrote:

Joseph wrote -


I am considering getting a power meter, so I am evaluating my options.

You could also consider the ergomo bottom bracket measuring device - see
http://www.bicyclepowermeters.com/


That looks pretty nice. Suits my desire for equipment independence.


My lbs guy told me -

1. The ergomo only measures power on one crank and interpolates what the
power is on the other - the SRM 4 way system is more accurate in that
regard.


Do you know how it interpolates? Does it just guess?

I managed to duck all the pretty girls appearently needed to flog this
product, and a salestype confessed when pressed that they just assume
that the right leg is equal to your left leg. Nothing clever, just
straightforward multiplication. I lost interest.






--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

wrote:
Hi,

I am considering getting a power meter, so I am evaluating my options.
I have made a list with what the pros and cons are for me for the
different ones I am aware of. They are all expensive, so I don't list
that as a con for each one.

PowerTap
pros: a few models in different price ranges.
cons: I'd like to use for trainig and racing, so 2 hubs would be
expensive.

Have a wheelbuilder make the wheel a good one to do both. The hubs are
so heavy, making a 'race' wheel doesn't make sense. Altho all power
meters have the good and others, Powertap seems the best for the $.
Polar is very unreliable. Ergamo is another option. A BB based system.
They say they have improved the BB but the one I installed had the BB
bearings go south in about 2 weeks.

SRM
pros: allows any wheel
cons: I like my 195mm cranks, the longest SRM is 180mm.

Polar
pros: bike spec independant, altitude measurement.
cons: lots of wires, fiddly install, can't calibrate by standing on
pedal, silly watch type head unit (why isn't it shaped like a bike
computer?)

So what should I get? I am leaning toward the Polar despite it's issues
for the transportability.

Suggestions?

Joseph

Qui si parla Campagnolo wrote:
wrote:
Hi,

I am considering getting a power meter, so I am evaluating my options.
I have made a list with what the pros and cons are for me for the
different ones I am aware of. They are all expensive, so I don't list
that as a con for each one.

PowerTap
pros: a few models in different price ranges.
cons: I'd like to use for trainig and racing, so 2 hubs would be
expensive.

Have a wheelbuilder make the wheel a good one to do both. The hubs are
so heavy, making a 'race' wheel doesn't make sense. Altho all power
meters have the good and others, Powertap seems the best for the $.
Polar is very unreliable. Ergamo is another option. A BB based system.
They say they have improved the BB but the one I installed had the BB
bearings go south in about 2 weeks.

My "race" wheel is going to be a Zipp 404 that I don't want to get
chewed up riding in the rain, sand, etc of lots of everyday rides. I'm
leaning toward just having the Zipp with a PowerTap and normal
training/every-day wheels.

Joseph

wrote:
Qui si parla Campagnolo wrote:
wrote:
Hi,

I am considering getting a power meter, so I am evaluating my options.
I have made a list with what the pros and cons are for me for the
different ones I am aware of. They are all expensive, so I don't list
that as a con for each one.

PowerTap
pros: a few models in different price ranges.
cons: I'd like to use for trainig and racing, so 2 hubs would be
expensive.
Have a wheelbuilder make the wheel a good one to do both. The hubs are
so heavy, making a 'race' wheel doesn't make sense. Altho all power
meters have the good and others, Powertap seems the best for the $.
Polar is very unreliable. Ergamo is another option. A BB based system.
They say they have improved the BB but the one I installed had the BB
bearings go south in about 2 weeks.

My "race" wheel is going to be a Zipp 404 that I don't want to get
chewed up riding in the rain, sand, etc of lots of everyday rides. I'm
leaning toward just having the Zipp with a PowerTap and normal
training/every-day wheels.

Joseph

You surely know what works for you, but: if you get a race-only wheel
with a power meter, as soon as you realize that training with power is
great, you would also realize that you cannot/don't want to use your
nice wheel on training, except maybe when the weather and the road is
perfect.
The big question is: do you get a bigger benefit from a nice race-only
wheel or from a power meter available all the time? (If you have the $$$
for two power taps or an srm+a zipp, then no problem).
I know what I would answer, but it's just me.

Francesco