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MetriGear pedal-spindle power meter

This new powermeter looks interesting:
http://www.cyclingnews.com/features/on-show-interbike-2009-part-15http://www.metrigear.com/

A 50g, sub1k$ powermeter with 1.5% accuracy !

Was thinking about the pedal strain solution myself. What I don’t know is how much pedal strain is influenced by whether one pulls in awkward directions. If your push/pull is not perpendicular to the spindle, you will register a larger force than that delivered to the pedal. That may be particularly pronounced when climbing out of saddle and in sprints. Worse yet, I sometimes train simply trying to keep a certain wattage – in worst case, one would start pushing askew because it gives a higher reading for the same effort.

Interested to hear other peoples opinions/experiences.

ATB
Henrik
 
Mar 13, 2009
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Strain guages are directional, so in this case the unit should be able to separate your useful efforts from your ineffective. As mentioned in the cyclingnews article, for biomechanists etc, they can get all the data including which way your foot is pushing and when.
Bottom line this unit will not read high for ineffective pedalling.
 
Strain gauges may be directional, but it will not be easy to tell the difference between a force on the pedal and a torque around the pedal (perp to spindle). It is theoretically doable, and may'be they manage - but not easy.
 
Mar 31, 2009
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Great idea but rather limited, I mean almost nobody uses speedplay (I have never even seen a pair).

Shouldn't the line from the article read
For now, MetriGear has only partnered with Speedplay – in part due to the system's low-popularity...
I mean imagine if they partnered with Shimano or Look, more support and an viable user-base of more than a few hundred people.

Or am I missing something.
 
Mar 13, 2009
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All the force you apply should be perpendicular to the spindle, but you are concerned about the small amount that isn't? I don't imagine there is a whole lot of axial stress in the spindle, though I think they mention 4 strain guages, will still pick that up. I imagine with this set up a 3 dimensional vector for force can be established and only the useful component taken.
So they started with speedplay...who cares, like SRM soon there will be a version on everypedal going.
 
Mar 11, 2009
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igamogam said:
Great idea but rather limited, I mean almost nobody uses speedplay (I have never even seen a pair).

Uh, maybe it's a geographical location thing, but half the pro peloton seems to use Speedplay and I see these pedals all the time on amateur racers bikes.
 
Sep 30, 2009
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Interesting to see that this also contains accelerometers. Is this a first for power meters? I'm only aware of the other systems using strain gauges only.
 
nightfend said:
Uh, maybe it's a geographical location thing, but half the pro peloton seems to use Speedplay and I see these pedals all the time on amateur racers bikes.

They are popular in the U.S.

The big selling point seems to be that they took half the weight of the pedal and put it on the bottom of the shoe, which lets people marvel at how light their bike is when they are not clipped in. :)
 
Jul 10, 2009
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actualy the selling point is the free floating of the shoe while still attached to the pedal that reduces strain on the knee...but lets not let facts get in the way of a good rant...
 
Jul 10, 2009
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I think i read that the accelerometers were being used to measure cadence without having to use any additional instruments...i think it sound pretty interesting
 
Jul 28, 2009
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Gotta say I got my speedplay light actions for the float but I love the double sided entry! I no, I no, a real rider dosn't even notice flipping the pedal ever to clip in and I thought once my knee was better I'd go back to my keos but I'm a convert! OK rant bumming speedplays aside it's time to sound even more like a wannabe cyclist/triathlete by asking what exactly is the benefit of power meters for the average cyclist? I get that it helps see an improvement or plateau over time but surely a qualified coach that can tailor a program to your specific targeted events is a better investment? lol I'm probaly totally wrong or missing something really obvious but yeah jw!
 
Mar 13, 2009
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For a Tri Athlete and timetrialist, Power Meters are fantastic for pacing.
You accurately know what power you can produce at threshold and then keep yourself right at that limit without tipping yourself into the red.
It means that you never go out to hard only to explode towards the end or don't go hard enough.
A PM is also more accurate than heart rate due to the bodies natural variences. You may be dehydrated, tired, overtrained, anxious or any other number of things that affect HR but that doesn't mean you still cant produce your threshold power.
A PM also lets you see exactly were your weaknesses are and then you can specifically train those areas.
Really a PM is just another tool to using in a training program. It all means nought if you don't do the miles.
 
Mar 18, 2009
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BroDeal said:
Yup. No other pedal allows any rotation. :rolleyes:

Many do, but none offer the adjustable float that a Speedplay Zero has. I use them because I can set them to have no float at all, I can set the exact angle of each foot relative to the pedal spindle, and I can't pull straight up out of them like I can (and have) with Look and Shimano pedals.

As for the MetriGear power meter, it sounds great to me. I've always wanted a way to have a power meter that I can use on my road and track bikes. Problem solved.
 
Apr 1, 2009
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Ya the euros I ride with all wonder what the heck I'm doing with speed plays. I used look for years but had some issues with my knee and was recommended the speed plays I tried them and they really are great. they are also really light even with the cleat. Look at the nano for stupid light!

Anyways the power meter I'm sure will be used on other pedals very soon and now you can get a pair for your MTB as well!!! cool.

I can't wait to hear how they work in real life!

L
 
Jul 24, 2009
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Damn, we're working on a similar project here.

This pedal forces thing, combined with bio-feedback, could be very useful. According to Analytic Cycling's models, there are significant axial forces when pedaling.
If you can reduce these then your efficiency will likely improve a bit.

Efficiency is free speed!

Going from 23->25% efficiency is 10-15 W for a fit cyclist. But until the tests have been done I don't know how much can be gained here, could be more, could be less.

Pro cyclists can have quite high efficiency simply because they ride lots, but for the rest of us (I only race Cat II) our efficiency is a lot worse and some efficiency training will be really useful.

It could even help pros get back up to speed too (like after injury/illness).

I guess the race is on between them and us (and whoever else). :)
 
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I really think that your on to something your absolutely right this could have huge benefits as to which leg is stronger and where you apply the pressure when pedaling. I sure hop they are as good (and cheap) as they seem to be!
 
SierraRider said:
actualy the selling point is the free floating of the shoe while still attached to the pedal that reduces strain on the knee...but lets not let facts get in the way of a good rant...

Clipless pedals all do the same thing, a little differently. Speedplay has many advantages to Look type, specifically the Zero model. Double sided, easy entry, adjustable float, servicable pedal, ability to buy one pedal if ya crash and kill one. All these items are not found on Look type pedals, specifically LOOK. X series has 'free float', up to 36 degrees, and 'may' help knee issues, may not. Certainly not a panacea for knee pain.

If you weigh the pedal and cleat, Speedplay is in the same 'range' as others of the same price points. I used Campagnolo/Look for years, then Campagnolo ProFit, then to a 2 sided pedal for my fixie. Liked it so I switched to Zero for my road bicycles. BUT when I put them on, cleat in the same relative place as the Campagnolo cleat, they pretty much 'felt' the same.

If ya like Look or shimano type, use them but most any pedal these days will work. None really have any huge advantages over another, like pretty much everything 'bike' these days, from wheels, tires, groups, frames, handlebars....etc....
 
igamogam said:
Great idea but rather limited, I mean almost nobody uses speedplay (I have never even seen a pair).

Shouldn't the line from the article read I mean imagine if they partnered with Shimano or Look, more support and an viable user-base of more than a few hundred people.

Or am I missing something.

Having seen so many issues with Look, including a HUG recall, I'm surprised no bike shop there in France are interested in Speedplay. The work well, like any pedal, have more adjustability and servicability than Look or shimano type. Buy a pair off ebay and try them, be the first on your 'block' or whatever it's called in France.
 
Mar 11, 2009
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Speedplay's obviously suck. You can tell this by how poor Cancellara and Andy Schleck's results have been the past few years. If only they had used Look or Shimano pedals. :rolleyes:
 
Mar 13, 2009
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ihavenolimbs said:
This pedal forces thing, combined with bio-feedback, could be very useful. According to Analytic Cycling's models, there are significant axial forces when pedaling.
If you can reduce these then your efficiency will likely improve a bit.

Efficiency is free speed!

Going from 23->25% efficiency is 10-15 W for a fit cyclist. But until the tests have been done I don't know how much can be gained here, could be more, could be less.

Pro cyclists can have quite high efficiency simply because they ride lots, but for the rest of us (I only race Cat II) our efficiency is a lot worse and some efficiency training will be really useful.

It could even help pros get back up to speed too (like after injury/illness).

I guess the race is on between them and us (and whoever else). :)

axial to the crank or pedal spindle?