cadence & power in smart trainer

[tdcadillac]

Hello all,
I have been using the Kickr Snap the last 2 weeks with Sufferfest trial.
When the app is asking 50 on power and 90 on cadence I would never get that right. always needed to go to 70 on power to reach the cadence which requires a lot of shifting in the one hour session. I feel it is not smart control unit since I am doing much of the shifting?
I am new to this and might be doing something wrong. any suggestion that would help match the power/cadence with the app without a lot of shifting or is it normal?
Thank you

 

[si_c]

Most smart trainers have difficulty producing enough resistance for low-powers particularly at high cadence. The solution is to pick a very low gear to start with but even then there is a floor through which it is difficult to get below.

I have similar difficulty on my Tacx Flux trainer.

 

[T.M.H.N.E.T]

I know nothing of the sufferfest app setup but 50w@70rpm is incredibly low in either trainer mode (sim or slope/erg)

Something isn't right

 

[HarryTheDog]

Depends on the power of the rider, I use sufferfest and so did my partner who is a tiny 4ft 10 grandmother, her ftp was only 95 watts so a lot of the drills would ask for around 50 watts. My missus just had to use a very low spinny gear, turbo was non smart cheapo ( stages powermeter) so did not have a lot of resistance at all so did the job for her. Maybe the op is not particularly powerful.
I would advise the op to go for the power target rather than the cadence if they cant get the resistance on the turbo low enough or a low enough gear to spin in. I always find its a balancing act to get power/cadence/gears correct so usually aim for the power figure over the cadence figure.

 

[bridgy]

Hello all,
I have been using the Kickr Snap the last 2 weeks with Sufferfest trial.
When the app is asking 50 on power and 90 on cadence I would never get that right. always needed to go to 70 on power to reach the cadence which requires a lot of shifting in the one hour session. I feel it is not smart control unit since I am doing much of the shifting?
I am new to this and might be doing something wrong. any suggestion that would help match the power/cadence with the app without a lot of shifting or is it normal?
Thank you

I'm not an expert on sufferfest but what you are describing is a workout using something called ERG mode on a smart trainer. In ERG mode you should be able to adjust your cadence to whatever speed and the trainer will adjust the resistance to maintain a fixed target power level - e.g. as you increase cadence the resistance will go down but power output remains the same, and if you slow down your cadence the resistance will go up - again to keep the same power output. It can take a bit of getting used to, and I'd recommend starting in a relatively low gear in the small front ring - you shouldn't really need to change gear just adjust your cadence. You might want to check your settings that ERG mode is definitely switched on, as if it's disabled for any reason this may be the cause of your problem

 

[tdcadillac]

Most smart trainers have difficulty producing enough resistance for low-powers particularly at high cadence. The solution is to pick a very low gear to start with but even then there is a floor through which it is difficult to get below.

I have similar difficulty on my Tacx Flux trainer.

Thanks si_c I will do. So it is OK to keep changing gears even if I am on ERG smart control trainer?

 

[tdcadillac]

I know nothing of the sufferfest app setup but 50w@70rpm is incredibly low in either trainer mode (sim or slope/erg)

Something isn't right

the app has a training plan for novice. I was on cadence build up workout that required 50w with 70 rpm but 2 things: to be at 70 cadence I have to be at 70~ power. Also I have to keep changing gears even tough i am in ERG and the trainer is under control

 

[tdcadillac]

Depends on the power of the rider, I use sufferfest and so did my partner who is a tiny 4ft 10 grandmother, her ftp was only 95 watts so a lot of the drills would ask for around 50 watts. My missus just had to use a very low spinny gear, turbo was non smart cheapo ( stages powermeter) so did not have a lot of resistance at all so did the job for her. Maybe the op is not particularly powerful.
I would advise the op to go for the power target rather than the cadence if they cant get the resistance on the turbo low enough or a low enough gear to spin in. I always find its a balancing act to get power/cadence/gears correct so usually aim for the power figure over the cadence figure.

my FTP is 100 same as ur partner. I was on cadence build up workout that is why I wanted to focus on rpm but was tough to keep changing gears!

 

[tdcadillac]

I'm not an expert on sufferfest but what you are describing is a workout using something called ERG mode on a smart trainer. In ERG mode you should be able to adjust your cadence to whatever speed and the trainer will adjust the resistance to maintain a fixed target power level - e.g. as you increase cadence the resistance will go down but power output remains the same, and if you slow down your cadence the resistance will go up - again to keep the same power output. It can take a bit of getting used to, and I'd recommend starting in a relatively low gear in the small front ring - you shouldn't really need to change gear just adjust your cadence. You might want to check your settings that ERG mode is definitely switched on, as if it's disabled for any reason this may be the cause of your problem

Thank you. question: what do you mean "starting in a relatively low gear in the small front ring " do you mean the smaller ring in front and higher end rings on the back ?

 

[T.M.H.N.E.T]

You're creating the issue here, erg mode specifically doesn't require gear changing. The trainer will bring the resistance to you, regardless of cadence. A drop in cadence will increase the resistance, do it well enough and you will literally not be able to get on top of the gear again.

ERG mode is very weird to ride in initially. You DON'T need to be using larger chainring either, stick it in the lowest front ring and about the middle of the cassette and leave it there. A few seconds before the wattage is about to change in the workout, increase your cadence a little - it helps to get on top of the gear and lets the trainer bring the wattage to you, rather than you hunting for it.

Example: If I go from 2min @ 220w and the workout is about to be 10s at 400w - I pick my cadence up otherwise the resistance change stops dead, being such a short period it's impossible to get back on top of.

 

[tdcadillac]

You're creating the issue here, erg mode specifically doesn't require gear changing. The trainer will bring the resistance to you, regardless of cadence. A drop in cadence will increase the resistance, do it well enough and you will literally not be able to get on top of the gear again.

ERG mode is very weird to ride in initially. You DON'T need to be using larger chainring either, stick it in the lowest front ring and about the middle of the cassette and leave it there. A few seconds before the wattage is about to change in the workout, increase your cadence a little - it helps to get on top of the gear and lets the trainer bring the wattage to you, rather than you hunting for it.

Example: If I go from 2min @ 220w and the workout is about to be 10s at 400w - I pick my cadence up otherwise the resistance change stops dead, being such a short period it's impossible to get back on top of.

Yes that was part of my first questions. I didn't understand why I have to change gears in ERG mode. Thanks for sharing the tip to pick up the cadence before the resistance change. I think that will solve the problem. I will try to do that in my next workout. Thank you

 

[bridgy]

Thank you. question: what do you mean "starting in a relatively low gear in the small front ring " do you mean the smaller ring in front and higher end rings on the back ?

Sorry, I meant smaller ring in the front. And maybe try a middling gear on your rear cassette. It's a bit of a personal choice really but I just tend to find that works best for me, and too big a gear (big ring on front, small on back) can lead to a spiral of low cadence & high resistance if you're not careful

 

[HLaB]

Hello all,
I have been using the Kickr Snap the last 2 weeks with Sufferfest trial.
When the app is asking 50 on power and 90 on cadence I would never get that right. always needed to go to 70 on power to reach the cadence which requires a lot of shifting in the one hour session. I feel it is not smart control unit since I am doing much of the shifting?
I am new to this and might be doing something wrong. any suggestion that would help match the power/cadence with the app without a lot of shifting or is it normal?
Thank you

It took me a bit to get the hang of ERG. Forget about power and shifting and pedal at the desired cadence and the Smart trainer will eventually adjust the resistance to achieve that desired power for the rpm.

 

[Milkfloat]

I don't often ride at 50 watts, but I am pretty sure in ERG mode that at a cadence of 90 my Neo would read way above 50 if I were on the big chainring. There is always resistance somewhere in the system. I use the little chain ring and a medium cog on the cassette, mainly because I want to share the wear on my chainrings, but also because it is a bit quieter.

 

[HLaB]

I don't often ride at 50 watts, but I am pretty sure in ERG mode that at a cadence of 90 my Neo would read way above 50 if I were on the big chainring. There is always resistance somewhere in the system. I use the little chain ring and a medium cog on the cassette, mainly because I want to share the wear on my chainrings, but also because it is a bit quieter.

TrainerRoad recommends you do their workouts in the small ring as the Smart Trainers/ERG are more responsive.