Kickr mode for micro bursts

Hi all,

I grabbed a wahoo kickr this fall and have been using it in ERG mode. In general I love it, but I’m struggling with ERG mode for shorter, bursty intervals (Pierce, Spanish Needle). For me, going from 105 RPM at a working interval (say 340 w) to a resting interval results in a total spin out. I kind of expect that for ERG mode and have been trying Standard with resistance at 2 or 3 in the big ring. It mostly works great, but I tend to have to really rip on the pedals to get the flywheel moving at first which I understand is just part of the “fluid” resistance curve (and similar to riding outdoors). Still feels tough to wind it up every 15 seconds though.

Any advice on this? Would Resistance mode be better suited to micro-bursts with its linear resistance curve?

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I asked same question not long ago… I do most of my workouts in 52x16, but short bursts appear to come or fall too slow. As advised on this forum, reducing the flywheel speed seems to help. It something to do with how fast Kickr can execute commands, apparently slower flywheel speed helps with that.

This is what I was getting

Low gearing makes your flywheel spin faster and therefore have high inertia. This inertia is harder to quickly adapt to changes in wattage.

Here is a fuller explanation:

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I use the middle of my cassette and my 36 chain ring in the front and seem to have pretty good success with responsiveness in erg mode for workouts like Spanish Needle - your results will vary though

Been experimenting with my KICKR2017… Large Ring up front (52) and middle-ish on the back… this is the result from doing 30/30’s…

Yes I push the power on startup… so ignore that… look at the lag when dropping off… I was getting the same thing with the Small Ring…

Will be doing another 30/30 tonight and will be using the Small Ring up front to see if its any different and report back!

This makes a lot of sense. Going to see how ERG feels while pushing the small ring, high gear (I’ve tried small ring, middle of cassette before but that was way back before I knew how to keep ERG steady).

Anyone try these workouts with Standard / Resistance mode?

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I use a small ring/gear combo for microburst workouts in ERG mode and it’s worked fine. The flywheel doesn’t spin as fast and you have a chance to catch it (flywheel) during the rest interval. Microbursts using big ring/gear combo in ERG mode just doesn’t work. The flywheel spins way too fast and you need to have a very fast cadence to catch the next interval.


Kickr 2017 in Erg with 53x15 gearing and 90-105rpm. When going from end of work interval (high watts at 95-105rpm) to rest interval (low watts at 90rpm), it takes about 5-10 seconds of light spinning for the fast spinning flywheel to slow enough for pedals to catch up again at 90rpm.

I haven’t done any microburst intervals like Spanish Needle, time will tell but right now I think it will be straightforward to do them in a large gear.


Tomorrow morning I get to experience Spanish Needle!
Will a Kikr Core react fast enough in erg mode to be the preferred setting?

tagging along to look for future tips

I did Spanish Needle yesterday on Elite Zumo on a big ring in Erg and tbh it worked pretty well, that’s only 15/15 though so the rest interval is short, there were times when I wasnt engaging the gear but tbh that didn’t detract from the interval.

I really ought to try doing this type of work on a smaller gear to use the effect of flywheel speed more efficiently but I like the feel of the big ring.

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Have done 15/15 recently. In the erg mode they are…strange. Level mode was perfect (50/18, cadence around 100-110). Recently i am big fan of a level mode because it works in every scenario.

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Level mode at 2 or 3 ?

Tried 1 and 3. I like 3 more.

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Level Mode??

In trainerroad it is called standard mode, wahoo calls it level. So basically non-linear, exponential power to speed curve that controls trainer.

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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.

When you look at the final stats for the whole workout, do they match the targets? Like for the NP, IF, and kcal?

If so, then you’re probably experiencing a lap offset problem. I had (and still have) this on my H3 when doing these workouts in Erg mode. The interval starts, it takes a few seconds for the power to ramp up to the target, and my average power for the interval is too low. BUT it also takes a few seconds after the interval ends for the power to drop back down. The end result is that every individual interval looks weird, but overall I’m doing exactly the workout I’m supposed to.

After many, many attempts to “solve” this problem, I’ve decided I’m at peace just letting ERG do its job and responding to the resistance changes as they come. Almost every time, the workout winds up exactly on target for the overall goals.

Basically what I’m saying is: ignore the interval power you see on the screen while doing this type of workout, just concentrate on maintaining the cadence targets, and everything will probably be fine.

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You should be able to set the gradient in resistance mode to get it to line up better for you. The Kickr should be able to go down below 60w at reasonable hearings.

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Are you really talking about resistance mode or standard (level) mode? I know resistance mode on my Kickr v1 will let me pedal 90 rpm on 53x16 at about 150 watts at 15% resistance setting, so I’m pretty sure I could spin 100 rpm at 100 watts on the big ring at say 5% resistance setting…

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