New powermeter rumours

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efeballi
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by efeballi

+1.
Isn't this why Stages didn't release power meters for Campag and SRAM's carbon cranks?
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2015 Giant Propel Advanced
2015 Cannondale Supersix Evo
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Politecnico di Milano Ingegneria Meccanica

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jmilliron
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by jmilliron

Correct.
2013 Wilier Cento1 SR || 2009 Ridley Crossbow || 2011 Yeti AS-R 5 Carbon

by Weenie


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kulivontot
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by kulivontot

Ugly

mentok
Posts: 577
Joined: Sun Jan 01, 2012 9:58 am

by mentok

maquisard wrote:linear


this is what matters. if that can be achieved with a user applied glue job on different materials and carbon layups then they're onto something. if not, it will be junk. i'm still interested...

efeballi
Posts: 492
Joined: Tue Dec 17, 2013 2:50 pm
Location: Istanbul, hopefully not for long

by efeballi

The crank doesn't need to have a linear stress-strain curve but as maquisard mentioned, you'd need more data points (i.e. known, varying weights hanged from the pedals) for the system to plot the curve, or an approximation of it.
Not mentioning the imperfections of glue jobs...


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SHUT UP LEGS
2015 Giant Propel Advanced
2015 Cannondale Supersix Evo
2013 KTM Strada mod. (totaled)
2011 Pinarello Dogma 60.1(loaner)
2011 Scott SUB 45(sold)

Politecnico di Milano Ingegneria Meccanica

rma
Posts: 169
Joined: Mon Apr 21, 2014 9:17 pm
Location: Belo Horizonte, Brazil

by rma

Have yet to see if it will be accurate... still in my vaporware list

maquisard
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Location: France

by maquisard

Their patent application, haven't had time to dissect it in detail yet.

http://www.freepatentsonline.com/20130333489.pdf

Marin
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Location: Vienna Austria

by Marin

I can tell from the patent that their product is aimed at Bicycle Raiders, I do hope that I qualify!

eric
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by eric

Looks like the patent application says it'll measure crank arm bending and twisting, have a temperature sensor and the last claim is "control unit preprogrammed for auto-calibration".

Perhaps they will measure various cranks and program the device for them.

Sounds like it could be good but it has to make it to market first.

kulivontot
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Joined: Sun May 16, 2010 7:28 pm

by kulivontot

What is it about this product specifically that makes it seem like "vapor ware?"
Is it the price point? The hand-wavy PR piece without real technical data? Is it just skepticism because it seems too easy? Or just because we're used to under delivery in this space (ie: brim brothers/garmin vector)?

JackDaniels
Posts: 108
Joined: Tue Oct 04, 2011 5:15 am

by JackDaniels

kulivontot wrote:What is it about this product specifically that makes it seem like "vapor ware?"
Is it the price point? The hand-wavy PR piece without real technical data? Is it just skepticism because it seems too easy? Or just because we're used to under delivery in this space (ie: brim brothers/garmin vector)?



I think the following quote is pretty accurate.

DC Rainmaker wrote:Historically for companies those dreams have been dashed by the realities of bike distribution (costs associated with profits at each layer of the bike world), as well as the inability to get an accurate product. Every single person in the power meter industry will tell you that it’s easy to get 95% there, but it’s the last 5% of building a commercially available power meter (no matter the price) that spills the most blood for these companies.

davidalone
Posts: 622
Joined: Fri Feb 10, 2012 4:27 pm

by davidalone

Marquisard is right. I work with strain gauges for a living. on human bone, which is ALOT harder to deal with than an engineering material. but the concept is similar

in addition to ensuring a good bond between the gauge and the material surface, proper alignment of the gauge is critical, too. a gauge even one degree off will give you vastly different readings from another gauge. If they work with rosettes, ( a network of 3 strain gauges) then it's easier as those aren't so sensitive to misalignment, but then you still have to take care to put in in the correct location. i.e. say 5cm from the pedal spindle. but then, the strain 5cm from a pedal spindle on a dura ace 7900 crank will be different than that compared to a campag record. even worse if you have other factors like decals, lacquer, crankskins, coming into play.

Wattteam is either doing LOTS of testing and have a very powerful algorithm taking all these into account...or their data simply isn't very accurate.

Marin
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Location: Vienna Austria

by Marin

Or they have a clever calibration procedure.

eric
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by eric

The patent has a leaf spring to which strain gauge(s) are attached.

ParisCarbon
Posts: 1914
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

In the process of a possible new build and sorting through options... Campagnolo SRM is the way I am leaning now.. but with the new 4 bolt system they introduced.. is it even possible for SRM to integrate since there are now 8 chainring bolts??? I assume anyone wanting to use a Campy SRM will still use the current 5 bolt?? Anyone heard any rumors??? I just hope Campy continues making 5 bolt rings!!

by Weenie


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