Just finished ‘cadence builds and holds’ on Wahoo Kickr (2020 version). Found cadence dropout at 168rpm. Found useful article by DC Rainmaker about his Kickr cadence tests (https://www.dcrainmaker.com/2019/09/wahoo-adds-cadence-support-multichannel-bluetooth-to-kickr-core-trainers-via-firmware-update.html). It’s from 2019, but fundamentals of Kickr have changed little since that iteration.
I’ve been having issues with the wahoo cadence sensor. Mine is dropping out around 130-135, which makes measuring cadence build and hold very difficult. I hooked up a camera and worked through the frames today to see where I was actually at (240 peak cadence, 180 for most of the drill intervals). So obviously a bit disappointed that the cadence sensor can’t even read anything like this. Is this a faulty sensor, or it’s just a limitation of the design?
There seems to be a point at which the flywheel speed outstrips the ability of the cadence/power sensors to record movement from the pedal action. However, I wonder whether the cadence at which this occurs is dependent on gear selection; if in a high gear (eg big chainring +/- low down the cassette), does the flywheel reach the speed at which it the sensors fail at a relatively lower cadence? I am using Erg mode and my workouts are in the small chainring and middle of the cassette, so mine loses contact at 168rpm. If you are in a higher gear, perhaps the cadence loss occurs at lower cadence.
I will test this on my next ride.
It’s generally the pedalling rate that’s the limit independent of gear selection. It works by detecting the variability in the power delivery as you will generally have one peak power phase per side so two phases per full pedal revolution.
From my understanding, the drop out happens when the pedalling frequency basically outstrips the sampling frequency as it starts to miss one or more of those peaks.
Edit: @Supereggtooth apologies as I just re-read your comment and realise most of this you already covered/were aware of. The only clarification is that flywheel speed doesn’t affect it
Yeah it’s independent of gearing, though obviously if you have a hard gear set you’re unlikely to be doing a high cadence.
I’ve read a bit about the power phase limitation you describe; are there other types of cadence sensor I should be looking at? I’m aware there’s a magnetic type but I don’t know how it works.
168 is still way better than 130-135… What sensors are people using? Any other better technologies for it?
Yes, you are right. Tried big ring test and cadence dropped at around 168 again, despite much higher gearing. Looks like limitation of the sensors.
Have a couple of cadence sensor options: can use one of the Garmin sensors or my PowerTap pedals. Will see if they connect either of them to the sufferfest app later today. I am sure there are others.
If it’s any consolation… The wahoo sensor that drops out at 130-135 is still better than the bkool sensor. It honestly feels like it’s just making numbers up. Like you’ll be going at a constant cadence eg 90, but the read out is going between 50 and 120 Every second
Found this article of Sufferfest website
In terms of technology, the best is actually the old school magnet based sensors as they simply get the pulse each revolution. Obviously the downside with them is the need for a magnet.
With the accelerometer or power phase based ones you’re either going to reach a hard limit or the numbers aren’t likely to be reliable past a certain point. To be honest, I just wouldn’t worry about it. Although some of us like to see the numbers going up on these drills, the numbers don’t really matter. It’s all about the smoothness. And in reality anything that can go up to around 130/140 is ample for 99% of the riding you’ll do.
I wonder if there’s a good rain maker review of very high cadence. He was testing up to about 150 in article I read which wouldn’t work for us (170-250).
We could just pedal slower I guess
Yeah but the high cadence drills are more about training your nm system. The idea is that as your nm control gets better, you turn the muscles in and of more efficiently - so you get more actual power output, per unit of effort that you’re putting in.
The smoothness is obviously important, but it’s a slightly separate goal to absolute Max cadence. Like your 1 rep dead lift vs 12 reps are targeting different things.
But… If you can be smooth at 240…
But agreed. You don’t actually need to see the numbers to know if you’re doing well today. It does tick the reptile part of my brain though.
Yeah but the point is the “feel” is actually the most important indicator as it’s a smooth stroke that is the ultimate goal not actually the max rpms as a smooth stroke will be more efficient than bouncing, wobbling etc. The high cadence is just a way to expose/amplify any inefficiency as your NM system will effectively learn the path of least resistance. So just keep trying to pedal faster until you feel on the edge of being smooth and in control.
Over time you will be able/need to pedal faster as that point will increase.
I guess a more succinct way of saying it is that it’s not about hitting your max rpm, but about pedalling as fast as you can “whilst” staying smooth and in control.
I’ve also been experiencing cadence sensor dropouts, but at around >120rpm when connecting to Sufferfest via BTLE. The strange thing is that I also have it connected to my head unit via ANT+ and that records happily. (Yes, I’ve made sure that Sufferfest is reading from my cadence sensor rather than the trainer).
@pb07 where is your cadence sensor mounted, I was having problems with mine registering cadences below 60rpm when mounted on top of my shoe stuck it to the back of the crank and it now goes down to 30rpm. Could be something similar at high cadences due to how the sensor senses?
@JGreengrass mounted on the crank. I’ve got a separate sensor on my road bike. I haven’t tried to hit ridiculous cadence on the road, might try it this week if a suitable opportunity presents itself. I’ve got the same wahoo cadence sensor on the road bike, but it’s paired with the bolt via Bluetooth so will be interesting to see how it compares. I don’t expect to be pulling 240rpm on the road but >150 should be ok.