Mid drive ?

ElevenAD

Well-Known Member
just get a bike with a "Bafang Ultra" superior power and torque and you dont have to worry about shifting because the shift sensor will cut motor power like a clutch when you shift,judging by your OP you will probably be happier with a mid drive bike!






3..2..
 
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ElevenAD

Well-Known Member
Mid vs Hub Wars Part 29.

Try both out at a store if you can.

I think most feel Mids are good for power and hills... but one advantage of Hubs is most have the @Taylor57 feature... a throttle.
Bafang make 12 different Midrive motors that feature throttles, these LBS and Euro bikes really need to catch up already lol
 

Johnny

Well-Known Member
This comparison chart is a couple of years old and doesn't include the latest motor updates such as Yamaha's PW-X2 but it's still useful in comparing mid-drive torque vs cadence. My understanding is that the PW-X2 motpr extends its peak torque curve out past a cadence of 100rpm.

View attachment 76059
When pushed to their limits these mid-drives can eventually overheat. The manufacturers don't publish this data but the Grin Simulator estimates that the Bafang BBS02 will take 28 minutes to overheat at full throttle and no speed limiter (28.6mph). With a 28mph speed limiter (90% throttle) for a Class 3 ebike the motor does not overheat.

I can't speak to the Yamaha motor, but I have ridden my Brose motor (Specialized 1.3) at its peak torque/power output for relatively long periods of time with no over heating issues. The bike's torque sensor reports a peak power output of 800W under these conditions.

I know this graph and I really like Specialized being open about it. I am curious how the X2 and gen 4 Bosch looks. I expect gen 4 Bosch to have a closer curve to 2.1.

You can clearly see that even the best drops down to 60 nm around 90 rpm which translates into around 570W. Also the peak power output of 1.3 looks like it is less than 600W , are you certain 800W was not battery consumption ?

I really don't think X2 will come remotely close to 80 nm at 100 rpm since it will be way higher than the peak output.
 

FlatSix911

Well-Known Member
Region
USA
City
Silicon Valley
The new Yamaha X2 supports up to 170 rpm and the torque curve is significantly improved. ;)

1609907431752.png
 

Johnny

Well-Known Member
The new Yamaha X2 supports up to 170 rpm and the torque curve is significantly improved. ;)

View attachment 76085
Honestly this is just marketing, it gives absolutely no information.

To have 80nm at 170rpm that motor has to have almost 1.5Kw output maybe you can show me a document that states their peak power.


You efficiency comparison is a nice one. However as Linklemming stated, number of windings, stator size, gauge of wires, gearing, input voltage may change those curves. Overall it makes sense though.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
After the long debate here (which I overslept as I'm riding out for another 45 miles soon), I only need to add some clarifications from my side:
  • I thought the PW-X2 max torque was 85 Nm but it is 80 Nm, my bad. According to different tables, Brose TF motor offers 90 Nm but I think it is rather 85.
  • The maximum peak power of that motor (and of Brose TF) is 520 W
  • After 40 minutes of climbing in Turbo mode, the Specialized 1.2s/Brose TF motor heated up to 60 C (140 F) with the ambient temperature of 25 C (77 F). The maximum grade on that trip was 9.2%. Average speed on the 40.1 km (24.9 mi) loop with 708 m (2300 ft) elevation gain was 31.4 km/h (19.5 mph).
  • I used the 36/51t gearing in several situations on my Trance, always on mountain trail rides. I can remember the Great Owl Mt climb very well. (I had to lean on the handlebars heavily to avoid the wheelie there, true).
  • On another road mountain ride with my Vado, I had to use Turbo and 48/46t gearing to be able to climb the "Specialized Tarmac Roll" Strava segment. At the same segment, a roadie failed to ride at the steepest section. My brother riding my Trance had no issues there but he is a strong rider (I have ill legs).
The fact which cannot be denied is all big brands use MDMs from one of five motor brands. (The exception is made for some lightweight road e-bikes). And no, I don't want to discuss Stromer :)

1609919011675.png

Roadie Marcin completing the "Specialized Tarmac Roll" segment in Góry Izerskie. I don't need to add I and brother were uphill so fast I had time to walk my Vado back to the bend, take my camera out and shoot the pic of the roadie :)

1609919276004.png

At the hill. My brother (in yellow helmet) completed the 50+ mi / 5000 ft elevation gain trip on a single 500 Wh battery (but he's healthy).
 

Johnny

Well-Known Member
After 40 minutes of climbing in Turbo mode, the Specialized 1.2s/Brose TF motor heated up to 60 C (140 F) with the ambient temperature of 25 C (77 F). The maximum grade on that trip was 9.2%. Average speed on the 40.1 km (24.9 mi)
What was the average grade?
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
So you did almost %4 climb continuously at 25mph ?
I was riding in Turbo (my brother rode in Giant level 3 of 5) and we were actually doing our best for the 20.1 km (12.5 mi) uphill ride. Our average speed at the average 3.7% gradient was 29.4 km/h (18.3 mph). We rode uphill for 43 minutes net with total of 5 minutes of stops. (All data here refer to the uphill direction of our loop only).
P.S. I have split the original ride record of 08/09/2020 to extract the uphill ride from the loop.

1609960376904.png


1609960477292.png
 

Johnny

Well-Known Member
I was riding in Turbo (my brother rode in Giant level 3 of 5) and we were actually doing our best for the 20.1 km (12.5 mi) uphill ride. Our average speed at the average 3.7% gradient was 29.4 km/h (18.3 mph). We rode uphill for 43 minutes net with total of 5 minutes of stops. (All data here refer to the uphill direction of our loop only).
P.S. I have split the original ride record of 08/09/2020 to extract the uphill ride from the loop.

View attachment 76108

View attachment 76109

I see now it makes sense. I don't know what your effort was but I think the motor output was still around 400w which is reasonable.

On a side note this is quite a mild climb and a good hub will be faster on this one. It is %15-%20+ grades that mid drives will have the advantage.
 

Johnny

Well-Known Member
I'd love to see a Strava report.
When I receive my Stromer back from the shop I will record one for you, I live next to the hills so it is easy. Searched the ones I already had but they are older rides with my bosch cx however I am certain that I was significantly faster on mild climbs up to %10. At %15 I am faster with my mid drive (around 12mph with my bosch cx vs around 9-10 with Stromer, my average input was around 350W in those sections).
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
Stromer uses a DD motor, which is not your typical geared hub drive. I may to add Stromer is illegal outside Switzerland (that's why I didn't want to discuss the brand).
 

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
I know this graph and I really like Specialized being open about it. I am curious how the X2 and gen 4 Bosch looks. I expect gen 4 Bosch to have a closer curve to 2.1.

You can clearly see that even the best drops down to 60 nm around 90 rpm which translates into around 570W. Also the peak power output of 1.3 looks like it is less than 600W , are you certain 800W was not battery consumption ?

I really don't think X2 will come remotely close to 80 nm at 100 rpm since it will be way higher than the peak output.
The Mission Control app reports it as 'Motor Power'. There are 20 parameters that the app can display, four of these are battery power (Wh consumption, Wh/mile consumption, Wh power level, and % power level).
 

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
I know this graph and I really like Specialized being open about it. I am curious how the X2 and gen 4 Bosch looks. I expect gen 4 Bosch to have a closer curve to 2.1.

You can clearly see that even the best drops down to 60 nm around 90 rpm which translates into around 570W. Also the peak power output of 1.3 looks like it is less than 600W , are you certain 800W was not battery consumption ?

I really don't think X2 will come remotely close to 80 nm at 100 rpm since it will be way higher than the peak output.
This graph is from https://www.emtbforums.com/ ;
PWX2 motor curves.png

Max torque up to ~60rpm, max power @ ~105rpm.
 

Johnny

Well-Known Member
Stromer uses a DD motor, which is not your typical geared hub drive. I may to add Stromer is illegal outside Switzerland (that's why I didn't want to discuss the brand).
:) Stefan. First of all get your facts straight, Stromer is legal in the States and the power output is decreased significantly(200W less than the EU version) for that reason.
Second if we are talking about legal side of things isn't your other bike derestricted ? Is that legal ? Also these so called legal bikes can average quite a bit over the stated 250W. That may be legal on paper but obviously there is a loophole that these companies are exploiting.

Sorry to hear that you don't like Stromer. Well that doesn't change the fact that it is one of the best (if not the best) mass produced hub motor ebike out there. Maybe you should ask @linklemming for a strava segment of his CCX which has a geared Bafang motor. I would prefer he did a similar climb with his GMAC but I am afraid you will find an excuse for that one too. He also shared similar experiences and compared Brose and his hub motors several times for different grades even in this thread.

On a side note I believe FlatSix , Link and I are all living in Bay area so maybe after the pandemic we should just come together for a ride to compare hubs and mid drives.
 

linklemming

Well-Known Member
The fact which cannot be denied is all big brands use MDMs from one of five motor brands. (The exception is made for some lightweight road e-bikes). And no, I don't want to discuss Stromer :)
Nobody is disputing this as its pretty obvious.

Your conclusions from this (mid drives are better for every situation) are not realistic.

Mid-drives are better for every situation yet we cant discuss brands that arent available in Poland?? Your being silly again:rolleyes:

Congrats on actually using your 36t/51t.....once:), sounds like a mid-drive is the best "for you"
 
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linklemming

Well-Known Member
:) Stefan. First of all get your facts straight, Stromer is legal in the States and the power output is decreased significantly(200W less than the EU version) for that reason.
Second if we are talking about legal side of things isn't your other bike derestricted ? Is that legal ? Also these so called legal bikes can average quite a bit over the stated 250W. That may be legal on paper but obviously there is a loophole that these companies are exploiting.

Sorry to hear that you don't like Stromer. Well that doesn't change the fact that it is one of the best (if not the best) mass produced hub motor ebike out there. Maybe you should ask @linklemming for a strava segment of his CCX which has a geared Bafang motor. I would prefer he did a similar climb with his GMAC but I am afraid you will find an excuse for that one too. He also shared similar experiences and compared Brose and his hub motors several times for different grades even in this thread.

On a side note I believe FlatSix , Link and I are all living in Bay area so maybe after the pandemic we should just come together for a ride to compare hubs and mid drives.
I will probably never supply strava ride reports as I usually ride my ebikes from my house.

I did live in the bay area for 10 years (88-98) and loved MTBing there but I live in Colorado now.

I have a few rides in mind in boulder to test the climbing and thermal limits of my GMAC. I have no doubts on the climbing (I passed a guy on a Turbo Levo on a short 25% grade yesterday and actually did a small wheelie on accident as I passed him)
 
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Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
yet we cant discuss brands that arent available in Poland??
Which are illegal or not welcomed in the EU.
will probably never supply strava ride reports as I usually ride my ebikes from my house.
There are privacy settings in Strava that protect the privacy of your home location.

We've got a saying in Poland. "A cow that roars loud gives the least of milk" 🐄🇵🇱😄