SRM went lights out?

I may be stating the obvious, but check to see if your crank sensor hasn't moved and that the sensor cable is OK.

Max358 said:

I was doing some big gear power work this morning, 30 rpm @ 450w or so, and on the third repeat my SRM went to 0 watts and 0 cadence, but speed and hr were unaffected. High torque was being applied, but I don't think that would kill it unless it knocked something loose (but I don't see anything wrong). Not sure where to look for a solution (SRM website and manual were no help). Unit has about 400 hours on it, and powermeter is charged. Has anyone else seen this situation or know of a solution? I would hate to send it in, but may have to. Thanks for any advice -

Max358 said:

I was doing some big gear power work this morning, 30 rpm @ 450w or so, and on the third repeat my SRM went to 0 watts and 0 cadence, but speed and hr were unaffected. High torque was being applied, but I don't think that would kill it unless it knocked something loose (but I don't see anything wrong). Not sure where to look for a solution (SRM website and manual were no help). Unit has about 400 hours on it, and powermeter is charged. Has anyone else seen this situation or know of a solution? I would hate to send it in, but may have to. Thanks for any advice -

more than likely you have torn the power cable near the rear wheel, i've done it about ten times, new cables are $70!

Max358 said:

SRM recommends that one buys two wiring harnesses in order to easily diagnose some problems like this one. If you have a friend with a SRM that will do as well. Try moving a magnet past the crank sensor to see if that cable works and then try using the wheel magnet past the speed sensor to verify just that cable, making sure to use the mode button to turn on the SRM manually.

the holster said:

more than likely you have torn the power cable near the rear wheel, i've done it about ten times, new cables are $70!

Now see, this is what has me leery of buying one these (PT, Polar, Ergo whatever) powermeters. The initial price is bad enough, but I'm thinking it could quite easily become 2X the initial price within a year.

-Bikeguy

the holster said:

more than likely you have torn the power cable near the rear wheel, i've done it about ten times, new cables are $70!

I have to wonder exactly how you are doing this. In all these years, I've never damaged an SRM cable.

In fact, aside from $30 for battery replacements, I've spent no other money on my SRMs and that includes shipping as I've never had to send them in.

I think I have a diagnosis: The SRM cables were zip tied instead of using electrical tape, and I suspect the ties were crimping the wire from the crank pickup. I bet my high torque efforts had a little to do with it, wrenching the bike and all, but more caused by improper installation.

I hear you about the cost, I was certainly cursing the curse yesterday, but I think the shop just got a little agressive on the install.

Going to put on my spare wiring kit tonight using electrical tape. Another reason I like black frames....

Max358 said:

I think I have a diagnosis: The SRM cables were zip tied instead of using electrical tape, and I suspect the ties were crimping the wire from the crank pickup. I bet my high torque efforts had a little to do with it, wrenching the bike and all, but more caused by improper installation.

I hear you about the cost, I was certainly cursing the curse yesterday, but I think the shop just got a little agressive on the install.

Going to put on my spare wiring kit tonight using electrical tape. Another reason I like black frames....

Electrical tape comes in many colors.
The guys at the shop did not read the manual.
It says to use electrical tape IIRC.
For the reasons you state you have experienced I use electrical tape instead of zip ties for my PowerTap installs and those wiring harnesses have lasted much longer than the prior ones.

Squint said:

I have to wonder exactly how you are doing this. In all these years, I've never damaged an SRM cable.

In fact, aside from $30 for battery replacements, I've spent no other money on my SRMs and that includes shipping as I've never had to send them in.

travel, daily wear and tear, those things are fairly fragile.

by the way srm recommends that you replace the crankarms every year as they get very flexible and are suspectible to breakage, those cost about $175. so maybe you should think about spending a little money on it.

the holster said:

travel, daily wear and tear, those things are fairly fragile.

by the way srm recommends that you replace the crankarms every year as they get very flexible and are suspectible to breakage, those cost about $175. so maybe you should think about spending a little money on it.

Except they don't have the integrated crank arms listed - only the old style Campy/Octalink arms.

I splurged for the DA cranks. Do those need replacement every year? I hope not. My neighbor has a nice new ski boat with his home equity loan. Me, an extra pair of DA SRM cranks....😉

Max358 said:

I splurged for the DA cranks. Do those need replacement every year? I hope not. My neighbor has a nice new ski boat with his home equity loan. Me, an extra pair of DA SRM cranks....😉

no, only the orginal version

the holster said:

srm recommends that you replace the crankarms every year as they get very flexible and are suspectible to breakage, those cost about $175. so maybe you should think about spending a little money on it.

I am not aware of anyone who actually does this, nor have I ever heard of anyone breaking an SRM crankarm.

OP here.
Resolution: I sent the SRM back to their tech support in Colorado. Turns out a strain gauge was bad, so they replaced the unit for free and shipped it back within a week. Since I was doing big gear torque climbing at the time, I will take credit for ripping my SRM to pieces.😉
Not sure if SRM had any issues generally with the DA version, I've heard different things like "they are bombproof" to "the early DA versions had issues, but they fixed all of them." The product still seems tried and trued, and I expect no further issues. Kind of feeds the Ergomo fire though, don't it?

Max358 said:

OP here.
Kind of feeds the Ergomo fire though, don't it?

You need to check out the transit time to Germany and back for a comparison with Ergomo...