Tandem Power Measurement
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Tandem Power Measurement
Any info out there in BF land on options available for tandem power measurement (wireless) that would be compatible with a Garmin (ANT+)? I looked on the Saris website and nothing jumped out that appeared to be compatible with a rear-disc equipped, 145mm spacing tandem.
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I have not tried it, but it seems the iBike Power meter should work with your Garmin 705 Edge. The following link might be useful.
https://www.worldcycles.com/index.htm...rget=d184.html
https://www.worldcycles.com/index.htm...rget=d184.html
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rdtompki,
andyman is correct, we use the iBike with a 705 for the stoker to see realtime power, the set up works great.
andyman is correct, we use the iBike with a 705 for the stoker to see realtime power, the set up works great.
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Any info out there in BF land on options available for tandem power measurement (wireless) that would be compatible with a Garmin (ANT+)? I looked on the Saris website and nothing jumped out that appeared to be compatible with a rear-disc equipped, 145mm spacing tandem.
I don't think anyone in the TdF is using an iBike to measure power. SRM, Cinqo, and Powertap are the only real options for those guys.
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I don't see any tandems on the tour. Rick is asking about options for a tandem. We actually have experience with all types of power meters and we found that the iBike works without having it "rigged up" plus the iBike is about half the cost and not just "probalily" may work, we know it works on a tandem.
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Both my wife and I train and race with power on our single bikes. We considered the Ibike a couple of years ago and passed. We use both the Quarq Cinqo and PowerTap with a Garmin 705. I thought about using the Ibike for the tandem. Since we have not been riding the tandem much this summer it fell off the radar screen. I think everyone is familiar with Ibike's shortcomings. I can see how it could be of some value on the tandem. Speaking for myself, once you train with power, one gets good at estimating power based upon perceived effort. Obviously, not very accurate and on a tandem there are two people coordinating their effort. I can see how an Ibike feeding both Garmin 705s could add some value.
There is a new power meter coming out next year. Here are some details.
"Clark Foy of San Jose Bike Club has invented a new powermeter. It's
a bunch of accelerometers, stuffed into the hollow pedal spindle of a
Speedplay pedal. Not only does it yield power information measured
directly, it also measures left/right, and in each of the pedal circle
quadrants, so that feedback can be incorporated to improve
efficiency. It's wireless, and communicates to existing "head" units
which use the ANT protocol, which most use. Garmin is one such unit;
there are close to 10 brands that could work.
There are computer chips inside which are electrically reprogrammable,
so as the algorithms improve, the pedals can get "software upgraded".
Retail price will be something like $899, which includes the pedals
($200 retail price). You'll need to purchase one of the head units
separately, like a Garmin.
Product will be launched at Interbike, early production late Q4'09,
broader distribution in Q1'10."
This looks interesting for the tandem. When I first heard about this, I thought tandem and track. Speedplays are fine for tandem but I would not use them on the track.
I can see it now. Go out for a tandem ride and then download the individual power data to Training Peaks and let the discussion begin.
There is a new power meter coming out next year. Here are some details.
"Clark Foy of San Jose Bike Club has invented a new powermeter. It's
a bunch of accelerometers, stuffed into the hollow pedal spindle of a
Speedplay pedal. Not only does it yield power information measured
directly, it also measures left/right, and in each of the pedal circle
quadrants, so that feedback can be incorporated to improve
efficiency. It's wireless, and communicates to existing "head" units
which use the ANT protocol, which most use. Garmin is one such unit;
there are close to 10 brands that could work.
There are computer chips inside which are electrically reprogrammable,
so as the algorithms improve, the pedals can get "software upgraded".
Retail price will be something like $899, which includes the pedals
($200 retail price). You'll need to purchase one of the head units
separately, like a Garmin.
Product will be launched at Interbike, early production late Q4'09,
broader distribution in Q1'10."
This looks interesting for the tandem. When I first heard about this, I thought tandem and track. Speedplays are fine for tandem but I would not use them on the track.
I can see it now. Go out for a tandem ride and then download the individual power data to Training Peaks and let the discussion begin.
Last edited by Hermes; 09-09-09 at 10:57 AM.
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I have a Powertap (that doesn't see much use these days) and a Quarq/705 setup for my single bikes.
One problem with riding the tandem a lot, without a power meter is that it throws off tracking the cummulative matrices in Cycling Peaks. Hence, I would love a power meter that gives the power for both riders on the Tandem.
We thought about the I Bike, but in addition to the setup, and extrapolation issues, it wouldn't solve my problem of getting the Captain's only power.
Perhaps a Quarq for the captain, and a I bike? You'd need a crank, with a removable spider. I don't see an intrinsic reason you couldn't run an FSA Team issue, set up backwards, with some locktite on the pedal threads.
Also, there was a guy on here that had a tandem set up with dual SRM's. Rather pricey, but it was for a study presumably supported by a grant.
One problem with riding the tandem a lot, without a power meter is that it throws off tracking the cummulative matrices in Cycling Peaks. Hence, I would love a power meter that gives the power for both riders on the Tandem.
We thought about the I Bike, but in addition to the setup, and extrapolation issues, it wouldn't solve my problem of getting the Captain's only power.
Perhaps a Quarq for the captain, and a I bike? You'd need a crank, with a removable spider. I don't see an intrinsic reason you couldn't run an FSA Team issue, set up backwards, with some locktite on the pedal threads.
Also, there was a guy on here that had a tandem set up with dual SRM's. Rather pricey, but it was for a study presumably supported by a grant.
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You could get lost and die.
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You could hit a tree and die.
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#8
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There is a new power meter coming out next year. Here are some details.
"Clark Foy of San Jose Bike Club has invented a new powermeter. It's
a bunch of accelerometers, stuffed into the hollow pedal spindle of a
Speedplay pedal. Not only does it yield power information measured
directly, it also measures left/right, and in each of the pedal circle
quadrants, so that feedback can be incorporated to improve
efficiency. It's wireless, and communicates to existing "head" units
which use the ANT protocol, which most use. Garmin is one such unit;
there are close to 10 brands that could work.
There are computer chips inside which are electrically reprogrammable,
so as the algorithms improve, the pedals can get "software upgraded".
Retail price will be something like $899, which includes the pedals
($200 retail price). You'll need to purchase one of the head units
separately, like a Garmin.
Product will be launched at Interbike, early production late Q4'09,
broader distribution in Q1'10."
This sounds similar in concept to the Brim Brothers shoe based system. https://www.brimbrothers.com/
However, they've had trouble apparently with working it all out.
One problem would appear to be how the meter measures force in the up stroke, which would likely be a similar problem for the pedal based system.
I hope the Speedplay system makes it to production.
[Edit] actually reading it, it appears its a different system based on acceleromaters, not, pressure on the pedals.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
Last edited by merlinextraligh; 09-09-09 at 11:57 AM.
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Both my wife and I train and race with power on our single bikes. We considered the Ibike a couple of years ago and passed. We use both the Quarq Cinqo and PowerTap with a Garmin 705. I thought about using the Ibike for the tandem. Since we have not been riding the tandem much this summer it fell off the radar screen. I think everyone is familiar with Ibike's shortcomings. I can see how it could be of some value on the tandem. Speaking for myself, once you train with power, one gets good at estimating power based upon perceived effort. Obviously, not very accurate and on a tandem there are two people coordinating their effort. I can see how an Ibike feeding both Garmin 705s could add some value.
There is a new power meter coming out next year. Here are some details.
"Clark Foy of San Jose Bike Club has invented a new powermeter. It's
a bunch of accelerometers, stuffed into the hollow pedal spindle of a
Speedplay pedal. Not only does it yield power information measured
directly, it also measures left/right, and in each of the pedal circle
quadrants, so that feedback can be incorporated to improve
efficiency. It's wireless, and communicates to existing "head" units
which use the ANT protocol, which most use. Garmin is one such unit;
there are close to 10 brands that could work.
There are computer chips inside which are electrically reprogrammable,
so as the algorithms improve, the pedals can get "software upgraded".
Retail price will be something like $899, which includes the pedals
($200 retail price). You'll need to purchase one of the head units
separately, like a Garmin.
Product will be launched at Interbike, early production late Q4'09,
broader distribution in Q1'10."
This looks interesting for the tandem. When I first heard about this, I thought tandem and track. Speedplays are fine for tandem but I would not use them on the track.
I can see it now. Go out for a tandem ride and then download the individual power data to Training Peaks and let the discussion begin.
There is a new power meter coming out next year. Here are some details.
"Clark Foy of San Jose Bike Club has invented a new powermeter. It's
a bunch of accelerometers, stuffed into the hollow pedal spindle of a
Speedplay pedal. Not only does it yield power information measured
directly, it also measures left/right, and in each of the pedal circle
quadrants, so that feedback can be incorporated to improve
efficiency. It's wireless, and communicates to existing "head" units
which use the ANT protocol, which most use. Garmin is one such unit;
there are close to 10 brands that could work.
There are computer chips inside which are electrically reprogrammable,
so as the algorithms improve, the pedals can get "software upgraded".
Retail price will be something like $899, which includes the pedals
($200 retail price). You'll need to purchase one of the head units
separately, like a Garmin.
Product will be launched at Interbike, early production late Q4'09,
broader distribution in Q1'10."
This looks interesting for the tandem. When I first heard about this, I thought tandem and track. Speedplays are fine for tandem but I would not use them on the track.
I can see it now. Go out for a tandem ride and then download the individual power data to Training Peaks and let the discussion begin.
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I don't see any tandems on the tour. Rick is asking about options for a tandem. We actually have experience with all types of power meters and we found that the iBike works without having it "rigged up" plus the iBike is about half the cost and not just "probalily" may work, we know it works on a tandem.
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On our Davinci we would need identical crank-based power measurement units each of which needs to support a single, 36t chainring (on the left side). This is probably too expensive a solution given we're never going to race, but intriguing nevertheless. A better solution might be a Powetap hub for our single bikes which have identical 12-27 cassettes. I will look into the iBike as well. It appears it may develop useful information at a reasonable price, but I certainly wish the website were more forthcoming about the nature of the algorithms used short of revealing any of their precious IP.
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Hermes, you should give the iBike a try on your tandem, we also ride and train with power on our singles, and we've compared the numbers with the power tap and the Gen 3 iBike, the power numbers are almost identical! (the iBike of 2 years ago is not at all as good as the new Gen 3) You'll be surprise how much you can use power on the tandem, as you mentioned one gets good at estimating power based upon perceived effort, so we know how endurance power zone feels on our single and is not different on the tandem, all of our training on the tandem is with power and it really works. We have a combined FTP for the tandem, we got it by doing FTP tests and the numbers came almost identical to our individually FTP numbers (Adding the FTP of the two of us).
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On our Davinci we would need identical crank-based power measurement units each of which needs to support a single, 36t chainring (on the left side). This is probably too expensive a solution given we're never going to race, but intriguing nevertheless. A better solution might be a Powetap hub for our single bikes which have identical 12-27 cassettes. I will look into the iBike as well. It appears it may develop useful information at a reasonable price, but I certainly wish the website were more forthcoming about the nature of the algorithms used short of revealing any of their precious IP.
To the original question, as far as I can tell, since there's no crank or pedal based pressure sensor, you can only get total power, so if you're looking for something tandem-specific, you're not really getting it here. You can compute the total power, but you can't separate captain from stoker. If that's what you're looking for.
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...but it would appear that they use a MEMS accelerometer and calculated acceleration (from the wheel sensor) to compute actual acceleration and tilt. They also use two air pressure sensors, one with a port facing forward and another to the side to measure wind speed (this isn't right, but the error could probably be calibrated out). The main remaining input is cadence, measured conventionally. Optional other measurements include altitude and temperature, which appear to be used either to improve accuracy in other measurements or to fine tune things. A roll-down calibration followed by a curve fit allows a measurement of rolling resistance and air resistance. ...
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I think the Ibike is great or hopefully a pedal based system that will still be expensive but will also work on the road bikes.
And if I were going to use a crank based system and figure out a way to "make it work", I would use the Quarq. We have this technology on road bikes and it works well for less money than an SRM.
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Cash is always and issue but the SRM solution is not that straight forward. You need a timing chain on the captain and stoker cranks and typically a triple. I suppose one could be motivated and have some special work done on the SRMs to make it work.
I think the Ibike is great or hopefully a pedal based system that will still be expensive but will also work on the road bikes.
And if I were going to use a crank based system and figure out a way to "make it work", I would use the Quarq. We have this technology on road bikes and it works well for less money than an SRM.
I think the Ibike is great or hopefully a pedal based system that will still be expensive but will also work on the road bikes.
And if I were going to use a crank based system and figure out a way to "make it work", I would use the Quarq. We have this technology on road bikes and it works well for less money than an SRM.
I like seeing the power output from other people. I know my power will be similar and I get that information for about zero cost
Good luck with it. I'd like to see progression numbers over a training season.
This was a good read on the subject.
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I posted more for the gee whiz of look how much this stuff costs. I was pretty sure that cheaper solutions were available.
I like seeing the power output from other people. I know my power will be similar and I get that information for about zero cost
Good luck with it. I'd like to see progression numbers over a training season.
This was a good read on the subject.
I like seeing the power output from other people. I know my power will be similar and I get that information for about zero cost
Good luck with it. I'd like to see progression numbers over a training season.
This was a good read on the subject.
If a pedal based power solution becomes available that will work for the track, I would get two setups. Then I could easily swap pedals to the tandem and effectively set up the equivalent of four bikes with power. And BTW, the current SRM solution for a track bike is 3700 Euros if you are looking for a gee whiz factor.
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I'll just leech for the next decade or so
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I'm betting you could use any of the Quarq cranks now available turned backwards for the captain's crank, and etiher get the pedal threads redone, or use locktite.
Stoker's crank might be more problematic.
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A better read is Training and Racing with a Power Meter by Allen and Coggan. Training with power is much more than "knowing" your power or being able to say I produce X watts. It is about hitting power numbers that are meaningful to you over discreet periods of time to improve VO2 Max and Threshold Power as well as others. Downloading individual power numbers into Training Peaks Software and tracking progress becomes very meaningful and motivating. Post ride analysis leads to incite on how to increase performance. This benefit even makes the SRM cost justifiable. The question becomes how many power meters can one have and which bikes to equip to have it make sense when you are paying the cost. For us, we do not ride the tandem enough to justify yet another power meter solution.
If a pedal based power solution becomes available that will work for the track, I would get two setups. Then I could easily swap pedals to the tandem and effectively set up the equivalent of four bikes with power. And BTW, the current SRM solution for a track bike is 3700 Euros if you are looking for a gee whiz factor.
If a pedal based power solution becomes available that will work for the track, I would get two setups. Then I could easily swap pedals to the tandem and effectively set up the equivalent of four bikes with power. And BTW, the current SRM solution for a track bike is 3700 Euros if you are looking for a gee whiz factor.
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That is significantly more than the ~$3800 for the NIB Dura-Ace.
I'll just leech for the next decade or so
I'll just leech for the next decade or so
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Yes, reverse torque is important, particularly on the track.
IIRC I have heard that you can't use an ordinary bike powermeter backwards on the tandem because powermeters are set up to read zero when they see reverse power. For example if you freewheel down a hill then pedal backwards really fast you should see 5 or 10 Watts negative power. My bet is that you don't because it would look confusing so easier to drop the data.
IIRC I have heard that you can't use an ordinary bike powermeter backwards on the tandem because powermeters are set up to read zero when they see reverse power. For example if you freewheel down a hill then pedal backwards really fast you should see 5 or 10 Watts negative power. My bet is that you don't because it would look confusing so easier to drop the data.
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Pedal based power meter...pics from Interbike courtesy of Google wattage group.
Some photos from the pre-Interbike open house:
Information sheet, page 1:
https://www.flickr.com/photos/djconnel/3930884632/
Information sheet, page 2:
https://www.flickr.com/photos/djconnel/3931039857/
Blow-up from wall poster:
https://www.flickr.com/photos/djconnel/3930768660/
Souvenir water bottles :
https://www.flickr.com/photos/djconnel/3930768710/
Some photos from the pre-Interbike open house:
Information sheet, page 1:
https://www.flickr.com/photos/djconnel/3930884632/
Information sheet, page 2:
https://www.flickr.com/photos/djconnel/3931039857/
Blow-up from wall poster:
https://www.flickr.com/photos/djconnel/3930768660/
Souvenir water bottles :
https://www.flickr.com/photos/djconnel/3930768710/