globecanvas

Assuming it's the same battery that was in it when it flooded, I'm sure that's what killed it.

topflightpro

Here's another weird SRM story.

I bought my first SRM new almost two years ago. It worked great, so I bought a used one last summer - I was being lazy and didn't want to swap cranks between bikes. And then last fall, I replaced my nearly non-functional Garmin with a PC8.

Anyway, at some point in the last 5 months or so, I started seeing intermittent power drops but only on the SRM I purchased new and only when riding outside. Everything was fine on the SRM I bought used and everything was fine when I was on the rollers or trainer.

I followed all the SRM trouble shooting directions, but the power drops just kept getting more and more of a problem - to the point I was getting almost no power on rides. I ended up sending in the SRM for a battery replacement - the PC8 had said back in November that the battery was low, and when I spoke with SRM, they said keep riding it until it stopped giving me power. SRM did the battery replacement and calibration under warranty as the unit was only about 19 months old.

But that didn't fix the power drop issue. So, I grabbed my wife's Garmin 520, paired it to my SRM and rode with both the Garmin and the PC8. The PC8 lost power but the Garmin didn't, which told me it wasn't the SRM that was the problem, but the PC8.

SRM instructed me to change a couple settings in the PC8. That helped, but it didn't solve the problem - I still got a lot of zero power, but no actual drops.

As I was riding yesterday, frustrated by the power and cadence regularly dropping to zero, I recalled a question one of the SRM techs asked me during our troubleshooting: He wanted to know if they PC8 was on a TT bike and if there were any cables or bars blocking the signal. And I noticed my GoPro mount on my bar.

I took the mount off and all of the sudden, the PC8 worked perfectly. I had bought a cheap generic GoPro mount, and I am not sure what it was made of or why the problem got worse over time, but now that it is gone, everything is fine.

mike868y

yeah i'm going to replace it and see what happens. at least support got back to me. was out of town all weekend though so haven't had a chance to follow up with them.

spectastic

why is my garmin's avg power lower than the one on strava?

also, anyone know why it's taking so long for the garmin to compile the file? (you know, the hold reset in 3, 2, 1, 1, 1, 1, 1....*15 sec later* 0)

ancker

1) Because Strava is crap for measuring anything to do with power.
2) Try deleting some of the rides from your device. I found my 500 would get slower and slower as it got closer to full. My 510 doesn't have this problem.

shovelhd

About 200 hours.

spdntrxi

it's the way they handle non-moving time... it's different and can effect your power number.

tetonrider

i'm curious--why would this be? if they are processing a file that contains actual power data, why would there be material differences? they're really just displaying data or taking averages for a segment, right?

thanks for any insight.

spectastic

my garmin had exactly 1 activity... maybe I'll try it again tomorrow. see if it gets better

spdntrxi

with actual power data.. the difference I see in strava vs garmin is usually 3-4 watts .. what are you seeing ?

revchuck 

On rides with no stops, the APs I see when uploaded to Training Peaks and Strava via Garmin Connect are generally within a watt or two. On rides with stops (flat repair, nature break, etc.) the AP in Training Peaks will be lower because it's based on total time, whereas Strava's AP is based on riding time.

mike868y

i'm an idiot.

at some point in my carelessness i appear to have lost the o-ring (stages support wanted a picture of the inside of the unit). i'm unsure if this happened when i first got it or when i removed the cap to let it dry out.

since it worked seemingly fine friday and saturday until the battery died i'm guessing that riding w/o the o-ring caused the battery to drain too fast and that replacing the o-ring and the battery should sort me out. i've asked support if they can send me a new o-ring. for the time being i reinstalled my non-stages crank arm. i don't like the idea of riding w/o the o-ring.

jsk

I've never noticed any significant difference in AP between Garmin/Training Peaks and Strava when using a power meter. What I have noticed is that the Weighted Power and Training Load (Strava's names for NP and TSS) use a slightly different calculation. Stava must use a longer duration for the Weighted Power calculation, because it's pretty much always lower than NP; sometimes by just a few watts, sometimes by 20W or more. It seems that really hard efforts don't raise Weighted Power as much as they do NP.

spectastic

garmin clocked out at 195W avg. strava says 184W avg.

ancker

Sufferscore is almost always way off (compared to TSS or CA's "Load"). Average/Normalized power is different (not necessarily wrong, but different than Garmin and Cycling Analytics.) Basically, I had premium for a while and tried to compare the numbers with some relation to Garmin/CA and Strava was sometimes higher, sometimes lower, so I gave up. I still use strava, just not premium and only upload outdoor rides.

jsk

Strava's sufferscore has nothing to do with power or training load. Strava's equivalent of TSS is called training load. Suffer score is based solely on time spent in the various HR zones.

mike868y

stages was supposed to send me a battery door and an o-ring and instead i got 4 battery doors (which i didn't need) :/

topflightpro

Doesn't that just mean you are ready for the next four times it fails again?

mike868y

lol. to be fair, this whole issue may have been my fault. at some point i lost the o-ring. unsure if this was before or after the whole riding in the rain thing.

ancker

In preparations for moving my main bike to eTap, I'm piecing together a Force 22 group for my other bike so both will be 11 speed.

Can I use a SRAM 10 speed crankset with an otherwise full SRAM 22 group?

Ygduf

yes

globecanvas

+ 1 yes.

Supposedly the 22 rings last longer, but if you already have the 10 speed rings, just use them.

Ygduf

I have had chainrings last 25k+ miles.

After using Di2 on my new TT bike I do like the feel of electronic shifting. It's pretty slick.

shovelhd

Once you go tron you'll never go back - RacerEx.

PepeM

Does anyone here use the S-Works Turbo tires? They are currently buy one get one free. Are they any good? Thanks.