New powermeter rumours

[Spaetzle]

I have pictures and did a testrun vs my Stages SB20 today. Happy to share but don't know how to post pictures here

[toxin]

350€, nice. I have faith in magene to make it a functional product too

350€? I think you might be confusing Malaysian ringgit (RM) with Chinese renminbi (RMB). Link above is 550€.

Ah *f##k*, youre right

[Spaetzle]

There you go....

Favero Assioma PRO MX vs Stages SB20
https://zwiftpower.com/analysis.php?set_id=394817

[Spaetzle]

This was the first testrun --> https://zwiftpower.com/analysis.php?set_id=394821

Less deviation...between both testruns I have dismounted/mounted the pedals, incl. recalibration...

[TobinHatesYou]

I’ll note that the Stages SB20 is horrible (I own one) and massively overreports with fresh batteries. It also overreports if your knees track outward and underreports if your knees track inward.

[RDY]

I’ll note that the Stages SB20 is horrible (I own one) and massively overreports with fresh batteries. It also overreports if your knees track outward and underreports if your knees track inward.

How and where is power being measured??

[toxin]

On the cranks

[TobinHatesYou]

How and where is power being measured??

As toxin said, the SB20 is unique among indoor smart bikes in that it uses a pair of Stages Gen3 pods on bespoke crankarms for power reporting. The resistance unit, of course, is also a rudimentary power metering device. I had hoped that eventually Stages will enable users to read power directly off the resistance unit, though if they haven't done it by now, it's probably because it has accuracy issues of its own.

The best explanation I've seen fore the crankarms being wildly affected by knee tracking / stance is that the cranks are extremely stiff in the direction of rotation due to the thick bear claw design, but they are not laterally stiffer than regular crankarms. The strain gauges are calibrated against the extremely low torsional deflection, but they aren't oriented in a way where the more significant lateral deflection can be cancelled out.

[Spaetzle]

Here are some Pics of the new Faveros

[handler]

Hm.. Wonder if Assiomas still have issues with underreporting that have been proven in studies. https://www.researchgate.net/publicatio ... wer_Output
Scaling the Assiomas is usually needed for the multiplte pairs I have owned which is on par with the studie.

[RDY]

How and where is power being measured??

As toxin said, the SB20 is unique among indoor smart bikes in that it uses a pair of Stages Gen3 pods on bespoke crankarms for power reporting. The resistance unit, of course, is also a rudimentary power metering device. I had hoped that eventually Stages will enable users to read power directly off the resistance unit, though if they haven't done it by now, it's probably because it has accuracy issues of its own.

The best explanation I've seen fore the crankarms being wildly affected by knee tracking / stance is that the cranks are extremely stiff in the direction of rotation due to the thick bear claw design, but they are not laterally stiffer than regular crankarms. The strain gauges are calibrated against the extremely low torsional deflection, but they aren't oriented in a way where the more significant lateral deflection can be cancelled out.

I was briefly considering getting one, but now they're permanently out of stock in my territory. The above seems like a joke ... and seems born out by talking to a friend who has one. She's nearly 50, and in a ramp test on Zwift got a 270FTP. She couldn't believe it, put Assiomas on and repeated it. She got 263W that time with SB20 data, and 214W with the Assiomas. That's worse than Peloton.

[RDY]

Hm.. Wonder if Assiomas still have issues with underreporting that have been proven in studies. https://www.researchgate.net/publicatio ... wer_Output
Scaling the Assiomas is usually needed for the multiplte pairs I have owned which is on par with the studie.

FWIW though I don't own a pair, I used a pair to compare to an Elite Diretto XR and the two were virtually inseperable. Quarq DFour was about 3% under these, and Sigeyi just under 2% under.

[BikeTyson]

Hm.. Wonder if Assiomas still have issues with underreporting that have been proven in studies. https://www.researchgate.net/publicatio ... wer_Output
Scaling the Assiomas is usually needed for the multiplte pairs I have owned which is on par with the studie.

Have to say this is the first I've heard Assiomas reading off. I mean, GP Lama and DC Rainmaker use them as the benchmark for testing other power meters. Mine are dead on with my Magene spider and 4iiii left crank. All three read within 2-3W, but interestingly my Kickr reads around 8-10W lower than all of them.

Speaking to the Magene power pedals. I hope that the price comes down. Because from that link, at $615 USD there's really no reason to buy them over Assiomas. Priced in the $400-500 range though they could disrupt Favero's crown.

[TobinHatesYou]

Hm.. Wonder if Assiomas still have issues with underreporting that have been proven in studies. https://www.researchgate.net/publicatio ... wer_Output
Scaling the Assiomas is usually needed for the multiplte pairs I have owned which is on par with the studie.

Have to say this is the first I've heard Assiomas reading off. I mean, GP Lama and DC Rainmaker use them as the benchmark for testing other power meters. Mine are dead on with my Magene spider and 4iiii left crank. All three read within 2-3W, but interestingly my Kickr reads around 8-10W lower than all of them.

Speaking to the Magene power pedals. I hope that the price comes down. Because from that link, at $615 USD there's really no reason to buy them over Assiomas. Priced in the $400-500 range though they could disrupt Favero's crown.

Ray actually claims that a common issue is that the right pedal eventually starts to read high after a period of ownership.

[BikeTyson]

Hm.. Wonder if Assiomas still have issues with underreporting that have been proven in studies. https://www.researchgate.net/publicatio ... wer_Output
Scaling the Assiomas is usually needed for the multiplte pairs I have owned which is on par with the studie.

Have to say this is the first I've heard Assiomas reading off. I mean, GP Lama and DC Rainmaker use them as the benchmark for testing other power meters. Mine are dead on with my Magene spider and 4iiii left crank. All three read within 2-3W, but interestingly my Kickr reads around 8-10W lower than all of them.

Speaking to the Magene power pedals. I hope that the price comes down. Because from that link, at $615 USD there's really no reason to buy them over Assiomas. Priced in the $400-500 range though they could disrupt Favero's crown.

Ray actually claims that a common issue is that the right pedal eventually starts to read high after a period of ownership.

Interesting. Hadn't heard that. I'll have to run some tests with mine.