Apples to apples?

[John Thompson]

I currently ride a bike powered by the Bafang Ultra - 1000 w of power. It's a monster, and it gets my oldish, biggish self up the mountains where I ride - my typical ride days are a slow climb up 10 miles of fire road to the top of one of the Cascade foothills, taking in the view, and then zooming back down. But I look longingly at rigs like a Kenovo and love their true mtb soul - but balk when I think of the total power of the Bosch. I hear that the Bosch motors convert their power ultra efficiently, but I still have concerns that all of the Bosch clones just don't have the beef to get me to the top. So my question (and it's probably a fairer question for the Bosch forum so I will post it their too, but I would love to hear from Kenovo or Turbo Levo owners) is: is comparing these two motors true apples to apples, just looking at numbers? Or is there more to the picture that I am not seeing?

Thanks in advance, all.

 

[Sierratim]

Mid-dives like Bosh and Brose rate their motors for nominal power output, often 250W for Euro compliance. My understanding is that this is the power the motor can produce continuously at max specified ambient temps without overheating. Peak power is quite a bit higher, but there is a chance the motor thermal protectors will cut power.

I don't ride an eMTB like a Turvo Levo, but I do ride its close cousin, the Turbo Vado 5. My Brose motor is rated at 250W. Bench tests report 550W peak. I can monitor motor and rider power while I ride. At my max of 250-300W the motor peaks at 800W. It hasn't had any issues delivering this power continuously up several pretty steep hills here in the upper Sierra foothills to your south. I have an 11-speed drivetrain and have only once had to use the granny gear in a short section of an inside curve I had to take due to an oncoming car. The motor and I pulled this amazingly steep curve just fine. Haven't had to walk anything yet!

For reference, this torque speed curve compares the Levo motor (the 2.1) to the Vado 5 motor (the 1.3). Peak torques are comparable, but the Levo can provide this torque at lower cadences, good for starting up a hill.

You can generate similar curves for various Bafang motors using Grin Tech's MOTOR SIMULATOR. Varying the battery voltage, capacity, and controller output should generate curves that are reasonably representive of your bike. With your trail slope selected as well you could compare the Bafang torque speed curve to the above chart. If you're using less than 90Nm of torque, the Brose motors in the Specialized ebikes will do the job for you. In the sample I linked to I set the slope to 20% with 100kg bike & rider weight. The Bafang motor I selected delivered 54.2Nm at 752W to climb this grade. The Specialized/Brose motors could pull this grade. I have personally ridden steeper slopes on my Vado.

Hope this helps.

Ride On!

 

[Sierratim]

BTW - our LBS rents ebikes, including the Turbo Levo. Perhaps a shop near you rents them as well. It'd be fun to ride a rental up your favorite trail and see how it does.

 

[John Thompson]

You're a saint, Tim. Much appreciated! I'll check the simulator and reach out to my LBS ... have a few Specialized folks but I doubt they rent. We do have a big Trek outfit, and the Rail 7 might be a good analog?

 

[Sierratim]

You're a saint, Tim. Much appreciated! I'll check the simulator and reach out to my LBS ... have a few Specialized folks but I doubt they rent. We do have a big Trek outfit, and the Rail 7 might be a good analog?

Happy to help.

We don't have a Trek dealer in town so I haven't ridden a Rail 7 but its Bosh Perf CX motor is comparable to the Specialized/Brose 2.1 motor, but with slightly less peak torque. I believe its recently been upgraded to 85Nm, but your LBS would know for sure. I do like its 12-spd drivetrain with the 11-51 cassette! As my MTBing sons would say, "I'd ride that!"

 

[e-levity]

... is there more to the picture that I am not seeing?...

Hey John,

It really depends on what type of riding you like. If you lean toward the moto side of things then the more powerful the ebike the better. As Sierratim has pointed out the 250W nominal power bikes actually put out close to 800W peak power which will get you up the hill pretty darn quickly. It your riding is mostly non-technical fire roads the full Levo or Trek Rail may be your ticket.

However, if you want a more "bike-like" riding experience and prefer single track or technical terrain then you might consider something like the Levo SL. The SL motor (also in the Vado SL and Creo SL) has about half the power of the full Levo, but a bike with a comparable build is about 9 lb. lighter. This weight difference may not sound like much, but it has huge effect on handling. Sure there's less raw climbing power, but it's plenty for most situations - lower gears (and speeds) allow it to get up most anything its larger sibling can handle. And the lighter bike behaves better in most conditions.

For some of us SL bikes are the "Goldilocks" solution between regular bicycles and ebikes. For example, I went from having a mtb and road bike to a Levo for dirt and a Vado for pavement to a Levo SL and a Creo SL. So yeah, there may be more to the picture as well as other types of apples.

 

[Stefan Mikes]

Just a remark: The Turbo Levo is the Holy Grail of e-MTB. Kenevo is more an Enduro e-bike. Specialized have put more attention to the Levo, making it their flagship e-bike. The Levo SL is for strong, healthy MTBers, giving them the feel of a "true MTB".

As soon as the market is re-stocked, I suggest you John look to more brands and models. As a Giant Trance E+ 2 Pro owner, I'm positively shocked with performance of Giant e-MTBs, of which the Reign E+ is the Enduro king. There is a 2021 version of Giant Trance X E+ available now with impressive new features. I have never regretted buying the Trance E+, even if the Levo was my original target (but it was unavailable at that time).

Whatever to say: e-MTBers respect the 250 W (nominal) Class 1 e-bikes, and these e-bikes are admitted to many trails where regular bikes are allowed. Don't think in terms of motor power. The peak power of Specialized/Brose, Yamaha/Giant, Bosch or Shimano motors (especially the advertised EP8 yet to come) and the torque they offer are impressive. It is combined with class drive-train (often top-notch Shimano or SRAM drive-trains), proper geometry, and -- perhaps the most important -- these are lightweight as for e-bike. It is because the motor and the battery are lightweight. The 720 Wh battery of the Levo Comp is especially impressive.

Did I mention tubeless-ready wheels, excellent brakes or dropper-post? Full suspension from Fox or Rock Shox?

Relevant thread

 

[scout592]

John Thompson. You may want to look at the Watt Wagon offerings and read the posts on here about them. They have a new controller, Archon x1, they use with Bafang that smooths out the power of the Ultra motor. Also, none of the other motors mentioned have a throttle which may or may not be important to you.

 

[John Thompson]

You guys are all awesome. Thank you for a ton to think about, or, as e-levity put it perfectly, "more apples!"

 

[byunbee]

I’ve read that one of the main reasons for the 250W label from Bosch, Brose , Yamaha, and Shimano is to be able to legally fit within the EU regulations. Most likely these motors have much higher tolerances than what the manufacturers specify.

Bafang Ultra is in a different league in terms of power and Archon X1 makes the motor that much more pliant. However, you also have to take into account that too much power is not always a good thing when climbing steep gradients as you can also end up spinning the rear wheels or tipping over.

 

[Sierratim]

I’ve read that one of the main reasons for the 250W label from Bosch, Brose , Yamaha, and Shimano is to be able to legally fit within the EU regulations. Most likely these motors have much higher tolerances than what the manufacturers specify.

Bafang Ultra is in a different league in terms of power and Archon X1 makes the motor that much more pliant. However, you also have to take into account that too much power is not always a good thing when climbing steep gradients as you can also end up spinning the rear wheels or tipping over.

Not to mention compliance issues with the Fed definition of "bicycle" here in the States (<1hp/746W). Anything more is limited to private property or must be licensed as a scooter/motorcycle, etc. Local restrictions may be even more restrictive. I feel that those that choose to ride these overpowered ebikes put us all at risk of unneccessary regulatuon and restriction.