obsolete
- Thread starter JayVee
- Start date
tjeerdnet
New Member
@JayVee, I ordered my ST2 model 2018 two weeks ago and I got an internal spec sheet from my cycle shop where the 800W was also mentioned. I was confused and expected it to be 500W. I triple checked with my dealer and he was really sure the spec changed indeed to 800W. I checked the Stromer site since then and I can confirm their site is updated now also. It was 500W. Only one thing is still not clear to me; is this peak power or is the engine really improved?
D
Deleted member 803
Guest
The ST5 supposedly has an 800W motor.
Ravi Kempaiah
Well-Known Member
- Region
- Canada
- City
- Halifax
The 2018 models in the US are advertised at 750W as well. Looks like it's an improvement over the previous generation. Even this video talks about 800W.... interesting..
D
Deleted member 803
Guest
Thanks for the accuracy.
tjeerdnet
New Member
I think marketing pushed for advertising peak watts only. What you suggest would make more sense to people. For me the current 800W for the ST2 2018, I interpret it as a 300W improvement in performance compared to the 'old' 500W ST2. I still have no clue what it effectively means. I mailed Stromer about this a week ago and did not get a reply (yet).
Last edited:
bluecat
Well-Known Member
you're kidding ;-)
The good news is, the 800W are continuous output. The technical requirement says continuous output for at least 15 minutes. I thought, the new motors had already approx. 800W peak output. With this in mind, I expect the real additional power is significantly below 300W. With other words: The new measuring method - given by law - provides higher values. But also the firmware (and the hardware) is improved. So we end up at 800W.
In terms of model hierarchy: Different to cars, the max. torque is much more important. As you can see, the values are clearly increasing from ST1 up to ST5.
The remaining question is: How must the previously published 800W of the ST5 be seen?
D
Deleted member 803
Guest
One of the problem we have in the USA is that the marketing of a vendor's ebikes is not always done locally. The result is the local vendor team has to use websites, images, and product information that may not have been localized. This is a problem since vendors spec bikes differently by region. Not all vendors have this problem but it is common in the USA.
tjeerdnet
New Member
I have little to no knowledge about watt vs Newtonmeter (regarding the Stromer bikes). But can anybody explain like I'm five (ELI5) why the ST5 with 850W (as specified on the Stromer site) can deliver 48 Newtonmeter, while the ST2 model 2018 is specified as 800W, but 'only' delivers 40 Newtonmeter. As @bluecat mentions about the torque, what makes the difference in these motors despite the almost same amount of watts? Like I said, I need a quick course to understanding how this works 
from what I understood about rear-axle motors [i.e. a crystalite], the efficiency of the motor strongly depends on the rev speed. Below 5km/h the efficiency really goes down. For some motors of similar type, this can be as little as 10% ONLY, maybe the stromer motors are better than that, but still: going slowly uphill will consume a lot of power (800W or whatever the controller & battery & thermometer reading at the motor allow it) but might give just 80W mechanical power (and torque). 80W is only half of an average cyclist which you get "extra", so your steep uphill is not going to be easy, given the extra weight of your VAE. The rest is heat in the system if you go too slow (and which could potentially kill the magnets of the motor, hence the overheat protection). Above a certain speed the efficiency is good (maybe 80% at 15km/h, just guessing ?) . So the miracle happens if you go uphill with a certain minimum speed, choose the gear which is OK for your legs to do that... ;-) If someone would have a torque-power-efficiency vs speed diagram this would be great.
bluecat
Well-Known Member
Each concept has it purpose.
If you want to ride slowly uphill, buy a mid-drive. If you're willing and able to maintain speed on a certain level, buy a Stromer. The impression of a test ride is far better than every possible chart or diagram.
(Now, I'll unveil the secret of Stromer: Enough torque over broad speed range let you race uphill fast.)
Why would anyone want to go up a hill at only 5 km/h?
not want, have to, and you might not want to miss the pub behind the corner either ;-) Around here we have 20...30% hills. Also + luggage slows down. I have seen that the stromer "pulls much less" when <12km/h, I have to do quite a lot to keep up speed. Compared to me using the race bike I would thumb-estimate that I need still 2/3rd of effort on the stromer for the same steep uphill, going "as fast as possible" which is "pretty slow" then.
bluecat
Well-Known Member
With a Stromer on main roads over all the famous Swiss alpine passes? No problem, all of them are high, but with inclination <15%. On such roads, you'll be able maintain speed clearly over 20km/h on a Stromer.
But of course, there some narrow forest roads with much more inclination. As mentioned above, for these challenges, you rather buy the the bike from the company where Stromer was founded.
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