ok power meters
let's go back right to the stop there's
articles out there about which permitted
by which companies doing which where it
measures at how accurate is eccentric
seven that's one ride back to exactly
what a parameter is and how it works
majority the parameters out there used
strain gauges on a scale of Sydney
Harbour Bridge but a current through a
wire either side I can't even reach the
other side and as soon as that wire
changes
Ben's deflects or strains that current
will change and there you go
it measures the difference between the
two SRM will have four of those or a
devise not simply have bridges that
strain gauges and inside every strain
gauge base power meter that's pretty
much what you have strange themselves
shape light and pretty reliable Inside
take them outside into vibration rain
and the biggest one is temperature
change on a bike you looking at probably
anywhere between 50 degrees operating
temperature difference between maybe
negative 10 if you're in the northern
hemisphere riding in the snow and up to
50 degrees if you're in qatar or
something like that where the world
championships will be held this year
there's a big variants of of temperature
change that has a big impact also the
facing interim have about 20 years head
start on everyone else who came into the
market but just think of the middle
facing with another piece of metal and
it deflects so you're gonna have the
glue or the interface there as well and
that subject exactly the same problems
as the metal itself hate vibration
moisture everything so it's a big
problem here and at the raw level it
measures the strength which gives you a
torque value and then that applied to
your rpms will give you your power in
watts
what's now he's with the controversy
starts the constant is measuring in what
power that's a known value that's
measurable and it should be consistent
across any how many that you have no
matter where it actually measures it in
the spider in the pedals system further
down that measurement across those
strain gauges should give you your
output if you're doing a hundred what's
a hundred and fifty watts 200 watts with
an SRM you should be doing exactly the
same with the park exactly the same of
the stages in
this I'm going to kick up for curt
kinetic new smart trainer they should
all measure the same reality is it's not
the case the common saying is that a
ride with one parameter knows the power
around with two parameters is never sure
a bit of a joke but that's come to be I
guess accepted the big problem is now in
the industry that the companies who are
now players in the market of power
meters now I'm not just including SRM
and park and PowerTap in that wahoo
around the parameter industry elite tax
all those guys are a power meter
manufacturers they have to be accurate
and I have to be accurate across all
systems now you think this is actually
quite easy to do
why because they all major power in
watches that constant so you think they
all face different challenges depending
on where they measure power as well what
we're finding on the forums and online
is people saying help my stages rate
higher than my kicker my quarter grades
lower than mine ego and things like that
these companies are struggling with how
to actually deal with that because in
the past you had one parameter there's
your numbers but now you've got to how
do you know which ones writing which was
wrong
big challenges faced look a bit of the
feedback we got from a couple of the
company somebody sent me some feedback
about the quick enquiry they're putting
before buying a parameter one company
first day but there's no standard of
measurement yet in the industry that's
been a parameter company who does
measure in what's I'm not sure what's
going on there with their personal the
helpdesk another one was and this is
from a big player as well they mentioned
that depending on your bike fit that may
impact the accuracy of their power meter
that's completely over her you're
sitting on your bike you can be using a
handcycle those strain gauges are all
the same
it doesn't take anything into
consideration other than how hard
they're being pressed on so i think they
may have been confused with you know how
much power you can put a time
proposition versus how much power you
can put out on a road bike so the
variance in the coming weeks and coming
months when it's super super accurate
smart rain has come out for home and
people are putting their quarks stages
and everything on these companies gonna
have to really really step up their game
ok if you think to check if you think
your parameter is out first of all
number one update the firmware on your
power made always update to the latest
version if you hated to go the latest
version don't be going to the latest
version if it doesn't work
keep your manufacturer honest tell them
why it doesn't work tell them why they
need to fix it they will listen so
update the firmware to the latest
version again check your batteries 0 the
offset some manufacturers or some head
units will call this calibration it's
not calibration it doesn't change the
slope we just change the offset and
stabilizes the measurement if the slope
is incorrect your parameter will be
incorrect matter what so that's a whole
other topic that we're going to so check
your firmware check your batteries 0u
offset if that doesn't work is still
getting discrepancies going out to a
customer support keep him honest
so in summary power meters simple
devices bit like the Sydney Harbour
Bridge but they're super hard to get
right super hard to get accurate there's
no excuses if they're not kick
manufacturer honest
we'll do some more videos on this that
coloration all that later on let me know
what permitted you are
have you had any issues with it and what
I'm looking for in the future
alright thanks for watching