Greeting to all. I know this is an old (> 6 month) thread and have hope that it can be revived as a means to help solve a problem I’ve had using ERG mode in short (under 30 sec) micro burst intervals in particular.
Here goes: I’ve tried as hard as I could to meet the micro burst power targets in Spanish Needle -3 today using ERG mode with a 2017 Kickr but no matter what I did, the “felt” resistance did not ramp up until approximately six or seven seconds into each 15 sec micro burst and by default, did not ramp down for six to seven seconds into each 15 sec recovery interval. Keep in mind that I maintain a steady cadence throughout the bursts and the recoveries, and have long ago learned that boosting the cadence in ERG mode in an attempt to quickly build more power is counter-productive at best.
The end result is that I was unable to meet the prescribed power output of 140% FTP for the full 15 seconds and the resulting TR report reveals that I’m lucky to have made perhaps 80-90% of the interval power targets for nearly all of the 15 second micro bursts.
In other words, while the ‘listed’ resistance target immediately jumps from 40% FTP to 140% FTP in each of the 16 or so intervals in each set, the actual (or FELT) resistance only increases gradually and while I can ultimately make and hold the prescribed power, the problem is that the real power is not realized instantaneously. As a result, there’s only seven or eight seconds left in the true 140% FTP power mode, and by that point, there’s little to no chance to make enough power to meet the prescribed output with only half the interval left to do so.
Secondarily, I have previously tried using Resistance Mode during workouts with intervals less than 30 seconds or so in duration. However, these attempts were stymied before I could even get through the warmup as the gearing in my road bikes is so “high” that I’ve been unable to make power below 160 watts (maybe 60% FTP) at reasonably high cadences. For example, my preferred cadence is 90 rpm and that RPM makes approximately 160 watts of power while in the small ring and in a middle cog on my 10-11 speed road bikes with 52-36 x 11-32 or so gearing. Please know that while I’ve tried shifting into my lowest gear while trying to find low power outputs in Resistance mode, I have not tried using my lowest gearing while doing micro bursts in ERG mode, and wonder if perhaps slowing the flywheel as much as possible might serve as the best way to minimize lag time during dramatic and rapid power target changes.
Finally I find it hard to believe in this day and age of technological advances, that the solution to using Resistance Mode for me will be to purchase and install some super granny gearing including new cranks and derailleurs on my road bikes simply to be able to use Resistance rather than ERG mode on my 2017 Wahoo Kickr. That seems crazy to me what with both Campagnolo Record and Super Record setups, besides being ridiculous, the drivetrain updates would prove to be absolutely cost prohibitive for me
Super-frustrated for now and thankful to each of you for having read this far and remain hopeful my description provides you with enough information to offer guidance and advice to get me on track to successfully completing these workouts while remaining in ERG mode or optionally, with a ways and means to tackle Resistance mode without nearly completely rebuilding my darling road bikes in the process.