How do I level the playing field to make eMTB equal effort to 25lb MTB?

ottoshape

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#1
I'm trying to figure out how to calculate the minimum % of assistance needed in order to make a 50lb eMTB equal to riding the exact same platform, except weighing 25lbs. Power plant in use is the Shimano E8000 250W, with the 70 nm torque motor, 504 Wh battery.

This exercise is more than just mental machinations or to quash an argument. It would be cool to see if I am losing out on any conditioning or cardio improvements by using assistance levels over and above covering the eMTB weight penalty.

I could spend another 4-6k on a non eMTB MTB or just cut back the assistance to the point where I've leveled the playing field. The trouble is, I'm not mathematical enough to calculate this out! Could I please get some help with this conundrum?
 
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steve_sordy

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#2
You appear to want to experience the same level of effort, so one way would be to measure the effect on you.

Get yourself a cheap heart/pulse rate monitor. Ride a short course on your 25 lbs bike and note the peak heart rate, or do an assessment of your average.

Then repeat on your ebike in eco, but do the same short course in the same time. Compare the readings from the monitor.

There are a lot of variables here, the wind could be blowing in a different direction, the trail surface could be wet, you could be having a good day or a bad day, and so forth. But this is cheap and quick and you would have confidence in it, rather than a dodgy maths calculation.

It should be easy to do the maths as you are moving an extra 25 lbs over a known distance, rising and falling over the same height, and in the same time. What you don't know is the rolling resistance of the emtb vs your regular bike. It may have different diameter and width tyres, different tyre pressures and treads, and different resistance from the internal moving components of the hubs, suspension and gears (and the motor of course!). And even if you knew all that and could work it out in Watts, you would then need to determine what setting on the ebike gave you those watts.

Better to stick to the heart/pulse monitor! :)
 

ottoshape

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#3
I sold the MTB after I shelled out the money for the eMTB. I like your idea of checking the HRM, I wear one every ride. I'll have to see what kind of data I have from my pre-eMTB rides.

Without the MTB, I feel I'm just guessing. FWIW, the calc would assume the exact same bike except 25lbs lighter. I'm just trying to figure out how to cancel the weight penalty and put my eMTB at the same effort level as the lighter bike.

I
 

Gary

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#4
It can't be done.
Assuming you're actually mtbing and not just sat on your arse pedalling on smooth surfaces riding a 50lb mtb requires different muscle effort than riding a 25lb one even if you remove pedalling input data entirely.
My highest HRs are always recorded while descending with zero pedalling rather than climbing on all my mtbs.

for the sat down pedalling parts all you need to do is work out what wattage is required to accelerate and ascend on a 25lb heavier bike.
There are roadie wattage calcs online to work out this very calculation

I bet you wouldn't have as heavy/high rolling resistance tyres on a 25lb mtb.
Heavy super grippy tyres can require more wattage to move than the extra weight of the motor/battery.
 

steve_sordy

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#5
Another way is to ride with people on clockwork bikes and see how much slower you have to go. I have discovered that even in Eco, I have to deliberately hold back so as not to race away from them. And that is with people that I know are much younger and fitter than me. My motor is a Shimano Steps and the Eco setting is not adjustable.
 

steve_sordy

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#6
............
..........
My highest HRs are always recorded while descending with zero pedalling rather than climbing on all my mtbs.

...........................
That would be the fear/excitement factor kicking in! :LOL:

But then I'd guess that it would be the same irrespective of the bike. Or maybe not, there are some bikes I've had that I would not ride down a DH course if you paid me!:eek:
 

ottoshape

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#7
My highest HRs are always recorded while descending with zero pedalling rather than climbing on all my mtbs.
Yeah, my highest are not when pedaling hardest....

I bet you wouldn't have as heavy/high rolling resistance tyres on a 25lb mtb.
You are correct sir! I would not.

Another way is to ride with people on clockwork bikes and see how much slower you have to go. I have discovered that even in Eco, I have to deliberately hold back so as not to race away from them. And that is with people that I know are much younger and fitter than me. My motor is a Shimano Steps and the Eco setting is not adjustable.
I've found the exact same thing too! I can easily stay with a riding buddy who is 20 yrs younger using just ECO mode...
 

Gary

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#8
Eco puts me about level with a british XC champ effort wise.
and I'm about twice his age and 50% heavier
 

Gary

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#9
That would be the fear/excitement factor kicking in! :LOL:
no it wouldn't mate

upper/full body workout simply raises my HR higher

I'll happily ride a WC DH course or EWS Enduro stages on a 100mm hardtail

my descending HRs are similar on my Esommet (48lb) DH bike (35lb) and carbon Enduro bike (32lb) and 4X hardtail (25lb) times are scarily similar on the first 3 bikes.
hardtail only mentioned because it's as light as the OP seems to think is optimum
 

ottoshape

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#11
hardtail only mentioned because it's as light as the OP seems to think is optimum
I'm just throwing out 25lbs because IF I had the cash, I would get short travel FS MTB that weighs in that general area.
 

Gary

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#12
not being funny but unless you are a light ,fit and highly skilled rider a 25lb FS is kinda stupid

fuck off Steve ;)

Have a great weekend all !
 

highpeakrider

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#13
It’s never going to feel the same and I’m not sure how you would calculate it.
However if you have an iPhone you could download the new emax app and reduce eco mode down to a level where you are working as hard as a person on a mbt and your heart rate is raise to an equivalent level, that may be 30/30 or maybe less.
The bike will never feel as agile but you will work harder.
 

ottoshape

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#14
It’s never going to feel the same and I’m not sure how you would calculate it.
However if you have an iPhone you could download the new emax app and reduce eco mode down to a level where you are working as hard as a person on a mbt and your heart rate is raise to an equivalent level, that may be 30/30 or maybe less.
The bike will never feel as agile but you will work harder.
Thanks, emax is already in the toolbox...
 

HikerDave

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#15
I'm trying to figure out how to calculate the minimum % of assistance needed in order to make a 50lb eMTB equal to riding the exact same platform, except weighing 25lbs. Power plant in use is the Shimano E8000 250W, with the 70 nm torque motor, 504 Wh battery.

This exercise is more than just mental machinations or to quash an argument. It would be cool to see if I am losing out on any conditioning or cardio improvements by using assistance levels over and above covering the eMTB weight penalty.

I could spend another 4-6k on a non eMTB MTB or just cut back the assistance to the point where I've leveled the playing field. The trouble is, I'm not mathematical enough to calculate this out! Could I please get some help with this conundrum?
You’re overthinking this. You’ll ride faster on the eBike so you’ll have to ride farther; if you catch someone on a clockwork bike turn down the power until you can’t keep up or cycle between low assist and no assist.

If you want a precise number play around with the calculator at

Bike Calculator

I think that the assist level would be something like twenty percent for equivalent effort.
 

highpeakrider

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#16
I think after 2 rides I found it frustrating, seemed a bit like working harder on a heavy bike, still very early days of playing with levels, but I think I may end up with eco slightly lower, but high enough to still be able to push and work harder and combat the extra assistance with a longer but quicker ride with more hills.
 

galaga187

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#17
Friends on clockwork bikes seem to be either pushing really hard or cruising. I’m going to try a combination of OFF, low assist eco mode (12%) and a Trail assist mode (26%) on my levo next time.

Also I do use Blevo App for training to keep at specific HR and power outputs. If I looked at others power outputs on Strava I could match to that. Not sure if you have HR or power modes on your apps.
 

highpeakrider

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#18
Friends on clockwork bikes seem to be either pushing really hard or cruising. I’m going to try a combination of OFF, low assist eco mode (12%) and a Trail assist mode (26%) on my levo next time.

Also I do use Blevo App for training to keep at specific HR and power outputs. If I looked at others power outputs on Strava I could match to that. Not sure if you have HR or power modes on your apps.
Maybe try https://veloviewer.com/ for £10 a year you can view breakdowns of all strata segments and it should help you see what difference the changes are making.
 

ottoshape

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#19

outerlimits

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#20
12%
On a flat pathed surface. That’s for me, comparing to my Norco Sight.
 

Pdoz

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#21
It's a mtb, not a flat level surface bike.

You're going to do MORE work on an emtb than an oldbike, and even more work the higher the assistance level. I can ride all day in eco but am stuffed after an hour in full assist. Hitting EVERYTHING at speed is seriously hard work, none of this sitting down and spinning cranks on the uphill sections - you're tossing around a full suspension bike uphill , and you'll still be pumping as much human legpower into those cranks - just having to work the upper body as well.

Best way to measure this is a tape measure around your waist....
 

outerlimits

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#22
It's a mtb, not a flat level surface bike.

You're going to do MORE work on an emtb than an oldbike, and even more work the higher the assistance level. I can ride all day in eco but am stuffed after an hour in full assist. Hitting EVERYTHING at speed is seriously hard work, none of this sitting down and spinning cranks on the uphill sections - you're tossing around a full suspension bike uphill , and you'll still be pumping as much human legpower into those cranks - just having to work the upper body as well.

Best way to measure this is a tape measure around your waist....
Flat paved surface is the only way to get anywhere close to an accurate figure.
I say just ride ya fn bike and have fun. Simples 🤷‍♂️
 

HikerDave

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#23
12%
On a flat pathed surface. That’s for me, comparing to my Norco Sight.
The motor itself probably takes an extra 5 to ten watts just to spin itself so I’d take a comparison with the bike calculator as a lower bound. I added this SWAG to the bike calculator value when I guesstimated twenty percent. :)
 

outerlimits

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The motor itself probably takes an extra 5 to ten watts just to spin itself so I’d take a comparison with the bike calculator as a lower bound. I added this SWAG to the bike calculator value when I guesstimated twenty percent. :)
I done real world testing
No animals were harmed in this testing.
 

Doomanic

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#25
Just get some fitter mates...
 

steve_sordy

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#26
This may sound totally off the wall.....

But I don't want my emtb to feel like I'm riding a clockwork bike!

My lightweight high spec clockwork bike did not stop my knees from hurting, but the emtb makes the pain go away! :love:

My Whyte T130C RS 2017 is now on eBay at £1800.(size Large, in black). :giggle:
 

stiv674

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#27
How many on here ride their emtb primarily for fitness rather than for pleasure?

Getting fitter is just a bonus as far as I'm concerned.
 

Pdoz

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#28
How many on here ride their emtb primarily for fitness rather than for pleasure?

Getting fitter is just a bonus as far as I'm concerned.
That's a bit like asking if you have sex for pleasure or the orgasm. I'll take both, thanks. ( yeah, ok, I'm not going to be checking a heart rate monitor during sex....point taken)
 

njn

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#29
I recently rode with the motor off for most of the ride, it wasn't as bad as I imagined. In eco, I walked away from the other rider on a normal bike.

Eco has too much assist to compensate for the extra weight.
 

dirt huffer

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#30
I would do some reading up on cycle training and look into heart rate zone training and get a Garmin Edge 500. That way you can monitor and track your effort. It doesn't matter what bike you ride, just the amount of effort you're putting into riding - which a heart rate monitor is a cheap way of monitoring that.

You could also look into getting your V02 max tested if you really want to dive deeper into more accurately tracking your training.
 

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