Here's Why Shimano Motors Aren't Great For eMTB racing

RickBullotta

E*POWAH Elite World Champion
Jun 5, 2019
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The assistance drops off considerably more steeply and earlier than with Specialized Levo bikes - thus those bikes are able to maintain a 1-2 MPH advantage at the limit. I've lived it and seen it in action, which kinda sucks. It would be great if Shimano would let us customize the fall-off point and rate.


ShimanoBoostChart.png
 

Gary

Old Tartan Bollocks
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Mar 29, 2018
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My E8000 does have a customised cut off point. I didn't ask Shimano's permisio

Emtb racing is stupid. If you don't want it to be quite so stupid simply stop doing it. ;)

The Levo's Brose motor has more Torque.
 

RickBullotta

E*POWAH Elite World Champion
Jun 5, 2019
1,849
1,579
USA
My E8000 does have a customised cut off point. I didn't ask Shimano's permisio

Emtb racing is stupid. If you don't want it to be quite so stupid simply stop doing it. ;)

The Levo's Brose motor has more Torque.

Please tell me more about "does have a customised cut off point"...
 

Gary

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I actually like the way a Shimano Steps motor's asist ratio eases off towards reaching (and exceeding) the assistance limit. If nothing else It reduces the instances of "pedalling through treacle" claims from unfit/heavy riders with super draggy tyres. ;)
 

mtbbiker

Active member
Sep 15, 2018
111
114
Murrieta
The assistance drops off considerably more steeply and earlier than with Specialized Levo bikes - thus those bikes are able to maintain a 1-2 MPH advantage at the limit. I've lived it and seen it in action, which kinda sucks. It would be great if Shimano would let us customize the fall-off point and rate.


View attachment 27214

Out of curiosity, does your speed cut off just before 20mph?
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
The assistance drops off considerably more steeply and earlier than with Specialized Levo bikes - thus those bikes are able to maintain a 1-2 MPH advantage at the limit.

it may reduce assistance earlier and more steeply, however having raced both I vastly prefer the Shimano motor as when I got to 32kph I was able to pedal through and gain an extra 2-5 kph in some sections where with the Levo motor I just could not pedal through - and that was with the original motor and the replacement.
 

mtbbiker

Active member
Sep 15, 2018
111
114
Murrieta
Out of curiosity, does your speed cut off just before 20mph?

18.0 to 18.5 it starts to fade.

Are you not willing to use Stunlocker or Emaxx to increase tire diameter to the point it shuts off at 20mph? I don’t think that would be cheating as long as you don’t go past 20mph, you’re just correcting for slightly wrong tire size in the Shimano programming.
 

Zimmerframe

MUPPET
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Jun 12, 2019
14,028
20,818
Brittany, France
My Shimano cut off about 3kph too slow compared to GPS readings.

I used stunlocker to reduce the wheel size until it matched the correct speed.

Didn't actually check if the wheel size was correct or if the Shimano just has a larger safe margin/error in how it's calculated.
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
Didn't actually check if the wheel size was correct or if the Shimano just has a larger safe margin/error in how it's calculated.

Because the motor will go into a wide range of bikes Shimano has a random size as default.
One of the first things my Scott dealer (Cycology My Ride, Hamilton) did once the bike was assembled was to update all of the firmware. After that he adjusted to the correct wheel size and then made sure it was on 32kph and not 25.

^^ One of the reasons you look for a good dealer and give them as much business as possible to ensure they keep on trading IMHO ^^
 

Fx1

Auto WARNING : Possible Duplicate user : "Zero"
Feb 6, 2020
267
203
GB
My Shimano cut off about 3kph too slow compared to GPS readings.

I used stunlocker to reduce the wheel size until it matched the correct speed.

Didn't actually check if the wheel size was correct or if the Shimano just has a larger safe margin/error in how it's calculated.
Does stunlocker work on the latest firmware?

I want to change tyre sizes and dont want to be slower for it. 15mph already sucks
 

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