Guy at work has bought a Specialized Turbo Levo which has a motor that puts out 585 watts. Looking at other brands they all seem to have 250 w motors. Why is the Spesh one so much more powerful and why aren’t Bosch and Shimano producing motors with the same wattage? By comparison the Spesh motor has 90Nm and Bosch is 85Nm. How come the power is so much higher but the torque is only a small bit higher? Can someone explain these options to me please? Ta muchly.

From the Spesh website:

Specialized 2.1, custom Rx Trail-tuned motor, 250W nominal

Not sure where you got your figure from?

Si

250w continuous output is the legal maximum. Someone is telling porkies. Maybe confused with the battery capacity?

Motors are rated at 250W continuous, they all produce considerably more at peak output.

https://www.specialized.com/gb/en/turbo-levo

Second paragraph on this page says 565 watts.

Second paragraph on this page says 565 watts.

Peak power

So if peak power is higher than motor capacity, how do you know what other manufacturer’s motors are capable of putting out?

how do you know what other manufacturer’s motors are capable of putting out?

You don’t unless they tell you

Peak power is meaningless. Could be for 2 feet

how do you know what other manufacturer’s motors are capable of putting out?

You don’t unless they tell you

That no one motor significantly outperforms the rest is a good indicator that they are pretty well matched.

Yeah in terms of performance I think they’re all much of a muchness between the shimano, bosch, brose(specialized) and yamaha.

Where they differ is in other areas such as :

-weight
-drag when the motor switches off
-reliability
-noise, both motor noise and rattles
-size which then dictates any constraints around suspension design, pivot locations etc.
-responsiveness of the motor.

Theres another little thing I’ve seen on youtube – I forget which. It was to address a problem of the motor stopping when you stop peddling and theirs had a feature where the motor kept on for a little bit.
It was on the uphill sections of a rut or gap where you maybe need level pedals and not to be peddaling so you lose too much momentum.
Might just be a software thing but seems something to consider.

The motor running on is not a good thing. It makes riding slippery technical climbs impossible/dangerous. I can’t believe that anyone would consider it a benefit.

The Specialized Brose motor should cut out within 0.2 seconds. If it doesn’t, then there is something wrong which may require a replacement motor to remedy.

I think I might be heading for my FOURTH. Not happy.

I have Shimano e8000.
I think it’s great

But I’d like it to have less drag when you go past 15mph
Be a little more controllable on boost mode
Work with my Garmin without buying some weird Bluetooth dongle

Seems the new EP8 fixes all that but is supposedly a bit more rattly?

Also, don’t worry about the power – there’s enough, trust me.
I ride on Eco generally

I ride on Eco generally

maybe its just me but I find it almost impossible not to ride in turbo mode all the time. Mind you – I was the same on motorbikes – throttle had two positions – off and full on. I find riding in eco pointless.

Turbo is too much on the e8000 – too hard to control on any kind of single-track.

I set eco mode to medium – feels like riding a normal bike but you’re amazing and handsome, have the wind at your back and just scoffed a bacon roll and a red bull

riding with non ebikes = eco or off

riding on my own or other ebikes up long boring fireroad/road = Turbo, up singletrack or downhill = emtb

Don’t like turbo on anything remotely technical. Even emtb can be too much in certain circumstances. Using it on fire road is fine but burns through the battery. Rode Comrie Croft last weekend as stuck it in tour for most of the day.
Bosch run on feature is hit or miss. Great for rock steps as it keeps pushing you and allows you to keep pedals flat. Not so good on tight rooty stuff as I can push you wide or spin the wheel when you want just momentum to carry you over.

Getting back to the OP, the nominal power must be 250W to comply with bicycle regulations but the way nominal power is technically defined it is averaged over a fairly significant period of time, I read the actual specifications once a few years ago but I forget the details, anyhow, what it means it is possible to have peak powers above 250W whilst still passing the approval test.

Anyway it seems there are two specifications that are important.

Torque – Basically do you have to be pedalling fast to get the maximum power. 90Nm (I assume at the crank) equates to 565W at 60RPM, so it seems you’ve got the peak power on tap even for slower pedalling.

Power curve – What is the peak power and how long is this held for before ramping down the power to maintain the 250W nominal power. I don’t really remember the details but the test specification was something along the lines of remaining below 250W average measured over a half hour period on on 100% throttle measured after a warm up period of about 20 minutes on a 70% throttle setting.

What I did remember was that due to the approval test specification being prescriptive it’d be possible to programme in a test defeat protocol but of course the ethics of this would bad just like the whole VW emissions scandal.

I’m slightly offended by Specialized saying that 240W is 2x Me when I’ve averaged more than that over several hours.