Some thoughts on using an ebike for Z2 training

[Katrina92]

I've been diving deep into everything ebike related lately cuz I'm thinking of getting an e-road bike (like I mentioned in a previous post).

Recently I had a thought—maybe I could use the future e-road bike not just for commuting, but also for doing Z2 training.

I live in an area with lots of short, steep climbs. When I ride my Addict past those hills, even if I shift down to the lowest gear and spin at a higher cadence, my hr still shoots up into Z3 or even Z4.

So I’m wondering—could I use the assist level on an ebike to stay in Z2 on those climbs? Basically adjusting the motor support to keep my hr mostly in Z2?

 

[Nomadmax]

It works. I have an Allant+ 8S that I use for around town errands and Z2 training days, especially after hard ride days. I also live where there's a hill whatever direction I go. I only use enough power to keep me in Z2 but do bump it up on the climbs. I opted for the Allant vs a an e road bike for 2 reasons. First, I wanted something practical to displace miles on my truck for short trips. Second, the upright position keeps me honest when using it for recovery days. If I had gotten a dedicated e road bike, I would have always been tempted to bury myself and get no Z2 benefit.

 

[Stefan Mikes]

I've been diving deep into everything ebike related lately cuz I'm thinking of getting an e-road bike (like I mentioned in a previous post).

Recently I had a thought—maybe I could use the future e-road bike not just for commuting, but also for doing Z2 training.

I live in an area with lots of short, steep climbs. When I ride my Addict past those hills, even if I shift down to the lowest gear and spin at a higher cadence, my hr still shoots up into Z3 or even Z4.

So I’m wondering—could I use the assist level on an ebike to stay in Z2 on those climbs? Basically adjusting the motor support to keep my hr mostly in Z2?

Katrina:
Specialized Creo 2 (as other Specialized SL e-bikes) has numerous tools to adjust the assistance for precisely matching your needs. Not sure how it is exactly done with the Road Remote (buttons installed under the bar tape) but there is so called Micro Tune mode that allows you setting the assistance in 10% intervals to give you exactly the assistance for a given Zone as you are riding. @Dazmanturbo and other Creo 2 riders: Could you use the MICRO mode with the Road Remote?

There is a feature of the Specialized App that is called Smart Control. Smart Control could work the way you were setting the base assistance and a threshold HR figure. An SL e-bike would control the assistance so you would have never gone above the HR set. I don't know if this feature has already been redeveloped in the new Specialized App though.

You can use the smartphone to precisely set the assistance for ECO, SPORT and TURBO presets.

Your effort is monitored on the Mastermind TCU display (you can also use a Wahoo, Garmin or Hammerhead as a superior display). Your leg power and cadence are displayed. Connect an HR monitor, and you'll see the HR bpm, too.

 

[Katrina92]

Katrina:
Specialized Creo 2 (as other Specialized SL e-bikes) has numerous tools to adjust the assistance for precisely matching your needs. Not sure how it is exactly done with the Road Remote (buttons installed under the bar tape) but there is so called Micro Tune mode that allows you setting the assistance in 10% intervals to give you exactly the assistance for a given Zone as you are riding. @Dazmanturbo and other Creo 2 riders: Could you use the MICRO mode with the Road Remote?

There is a feature of the Specialized App that is called Smart Control. Smart Control could work the way you were setting the base assistance and a threshold HR figure. An SL e-bike would control the assistance so you would have never gone above the HR set. I don't know if this feature has already been redeveloped in the new Specialized App though.

You can use the smartphone to precisely set the assistance for ECO, SPORT and TURBO presets.

Your effort is monitored on the Mastermind TCU display (you can also use a Wahoo, Garmin or Hammerhead as a superior display). Your leg power and cadence are displayed. Connect an HR monitor, and you'll see the HR bpm, too.

I'm curious, can it control the power?

 

[Katrina92]

It works. I have an Allant+ 8S that I use for around town errands and Z2 training days, especially after hard ride days. I also live where there's a hill whatever direction I go. I only use enough power to keep me in Z2 but do bump it up on the climbs. I opted for the Allant vs a an e road bike for 2 reasons. First, I wanted something practical to displace miles on my truck for short trips. Second, the upright position keeps me honest when using it for recovery days. If I had gotten a dedicated e road bike, I would have always been tempted to bury myself and get no Z2 benefit.

Can you keep your HR mostly in Z2 while going up and down hills with the e-assist?

 

[Nomadmax]

Can you keep your HR mostly in Z2 while going up and down hills with the e-assist?

Absolutely.

 

[mschwett]

Can you keep your HR mostly in Z2 while going up and down hills with the e-assist?

this is a possible use for an eBike, but it’s also a possible use for having the correct gearing for your climbs. you can either add power (requires a motor,) or go slower (requires gearing appropriate to keep your cadence up when crawling up a hill…)

 

[Jeremy McCreary]

you can either add power (requires a motor,) or go slower (requires gearing appropriate to keep your cadence up when crawling up a hill…)

Or do both, as I end up doing to maintain a mid-drive-friendly cadence on our steepest hills.

Lowered my 12-speed gearing to 22-100 gear-inches with a smaller chainring just for that purpose. Could still use a lower bottom gear now and then, but guessing that a cassette change would be expensive on a Vado SL.

 

[Jeremy McCreary]

The OP should be aware of the Carrot Effect — a curious ebike phenomenon wherein upping the assist triggers an unconscious increase in exertion.

Many of us have experienced this. If she wants to stay in Zone 2 on an ebike, she'll have to keep an eye out for it and adjust accordingly.

 

[Stefan Mikes]

I'm curious, can it control the power?

I do not think it can control the power per se but you get the leg power figure on the display (or a GPS bike computer), and you can adjust the motor power the way to maintain possibly constant leg power of yours.

 

[SbSteve]

This is from the Specialized Creo 2 manual, about the Smart Control feature of the app that Stefan mentioned above:

Activating Smart Control means you don't have to worry about the mode setting (off, eco, sport, or turbo) or the battery capacity during your ride. You can set the Smart Control by distance, duration, or heart rate goal and let your bike do the rest.

I can't comment on how well this works since I just got the bike, and I don't have a heart rate monitor, but presumably you enter your desired heart rate and the bike will automatically adjust the amount of power assist up or down to keep you in your desired Z2 range.

 

[Katrina92]

I do not think it can control the power per se but you get the leg power figure on the display (or a GPS bike computer), and you can adjust the motor power the way to maintain possibly constant leg power of yours.

Have you tried it out? I'm curious about the relationship between the motor's power and my own power output. If I want to boost my own power, should I dial back the assist and pump up my cadence? I've looked into it, power seems to be about torque times cadence.

 

[Stefan Mikes]

Have you tried it out? I'm curious about the relationship between the motor's power and my own power output. If I want to boost my own power, should I dial back the assist and pump up my cadence? I've looked into it, power seems to be about torque times cadence.

A mid-drive motor such as one found on Creo 2 provides more power if you input more leg power. As you know, the same leg power can be achieved either by mashing (hard pedalling at a low cadence) or spinning (furious pedalling at light feet pressure on the pedals), which is achieved by selecting the proper gear. Mid-drives love spinning, and the proper cadence just starts at 70 rpm with the ideal range at 80-90.

It is not happening automatically that reducing the assistance makes you pedal stronger, no. If you input a constant leg power and reduce the assistance (for instance, you go OFF) then the e-bike would just ride slower. However, reducing the assistance but attempting to ride at a constant speed would certainly force you to pedal stronger (you will see your power on the frame Mastermind TCU display or on a GPS bike computer connected to the e-bike, or on a smartphone with the app installed on your handlebar stem).

Of the people being racy road cyclist here, @mschwett is the right person to ask. Ask him, he knows everything on road e-bike workouts; he owns a Creo 1, a Scott Addict Eride, and an Aethos. (Only he does not read my posts).

This is from the Specialized Creo 2 manual, about the Smart Control feature of the app that Stefan mentioned above:

Activating Smart Control means you don't have to worry about the mode setting (off, eco, sport, or turbo) or the battery capacity during your ride. You can set the Smart Control by distance, duration, or heart rate goal and let your bike do the rest.

I can't comment on how well this works since I just got the bike, and I don't have a heart rate monitor, but presumably you enter your desired heart rate and the bike will automatically adjust the amount of power assist up or down to keep you in your desired Z2 range.

Thank you for confirming that! I think one needs to connect a HR monitor to the system to see the Smart Control/Heart Rate in the Specialized App.

Ah, @vado5.0slcreo2 could chime in, too!

 

[Jeremy McCreary]

I'm curious about the relationship between the motor's power and my own power output.

This relationship has the same mathematical structure in all Specialized mid-drives, but some of the controlling parameters vary from motor to motor.

Detailed explanation and interactive graphical model of the basics of this power-sensing PAS (pedal assist system) in normal riding with the Creo 2 as one example:

Visualizing and exploring the power-sensing PAS in Specialized mid-drives — an interactive graphical model

For our more math-minded Specialized mid-drive riders, here's an interactive graphical model of your bike's tunable power-sensing pedal assist system -- hereafter, just "PAS". The model doesn't cover complex PAS responses to transient events like starting out or approaching PAS cut-off speed...

forums.electricbikereview.com

Additional inputs like wheel speed and acceleration rate probably figure into special cases like starting out and approaching max assisted speed.

Overall, a flexible, well thought-out mid-drive PAS with completely natural power delivery on my Vado SL.