Power drop with steep gradient changes

In going from a steep gradient downhill section immediately into a steep gradient uphill section (such as in the rolling hills before the mountain summit) my power frequently drops to zero for 3-4 seconds even though I continue to pedal/put out power.  It then picks back up, but only after I’ve lost substantial speed.  Makes group rides very challenging.  This power drop ONLY occurs for me in these sections with quick changes in gradient, going from downhill to uphill.  It doesn’t matter if I’m changing gears or not at the time, still occurs.  I have the most up to date firmware.  Wondering if anybody else has had this issue with the Cycleops Hammer (which I’m running) or other trainers.  Thank you ahead of time for any help offered!

Make sure you’re running the latest firmware and that you connect by ANT+ FE-C if connecting by ANT+. A recent firmware update addressed this problem and it’s greatly improved however not totally eliminated.

Thanks for the response Nigel!  I’ve done both, latest firmware update and connecting via ANT+ FE-C, but still having problems as you alluded to.  Any idea if this is a problem that’s isolated to the Cycleops Hammer, or if other direct drive trainers are having the same issue?

I think it’s a Hammer issue. Your next port of call would be to file a support ticket with Cycleops. The problem can be resolved by using a power meter as your power source. Generally I use my power meter as the power source on Zwift but I’ve been doing a few tests not using it. I only get the occasional power drop to zero and then only momentarily. If I have power smoothing enabled in the settings which I normally do I don’t even notice the drops.

I’ve spoken with a representative on the Cycleops side of things and they seem to throw the ball back into Zwifts court. Was an odd response from them given that their latest firmware update purported to address this issue.

It’s a interesting as the two companies seem to have a partnership (with Zwift selling Cycleops equipment through their website) that this issue hasn’t been resolved. And if other trainers aren’t having this issue then I’d agree the problem would seem to lie with the Hammer.

Unfortunately I don’t have a power meter of my own to bypass the problem. Maybe the power smoothing enabling will help, can give that a try. The drops seem to last for 3-4 seconds though, so my guess is it will still be noticeable. Any other thoughts/recommendations?

All power smoothing does is average out the power you see on screen. It won’t prevent the power dropouts. It will mask the power dropouts.

I think one of the issues is staff at Cycleops don’t ride on Zwift enough to understand the problems. Likely they’re using their own Rouvy application for virtual rides.

I am having this issue again but only on inclines more than 11%. I stopped using Rouvy because the power loss was on every incline! I can deal with this - 11%+ isn’t that often but I’m and frustrated. The recent firmware update was supposed to address this but apparently has not.