Cargo bike Vogue Carry 2 | Bafang M400 | C07 | Lack of torque

saneagle

Esteemed Pedelecer
Oct 10, 2010
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Only if your cadence is at least 60 rpm. If you cannot manage cadence of 60 then the gearing is too high, so lower it enough to achieve 60, then see how it feels.

If your cadence is at least 60 then the other lines of enquiry carry more weight, but there is nothing to be done for a motor that cannot spin fast enough except allow it to spin fast enough!
Cadence doesn't normally affect the motor's torque unless there's some weird setting like keep current too low, then it works in reverse - if you pedal too fast, it reduces power. Spinning the motor faster would normally generate more power, but only if you can gear down to take advantage of it. How can you pedal faster if you don't have the power to climb? That's the problem that OP wants to solve.

From the description of the problem, I'd say that the keep current is set too low, the same as what some other forum members experienced with their various Bafang mid-drives. OP needs to find out what it's set to.


 
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cyclebuddy

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Nov 2, 2016
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@guerney is right in post #10. You can spin at 60rpm but once you're there, it "keeps current" at 30% in @guerneys example screenshot, which is typical. You can up it to 100% as @guerney has done, and it'll "keep" applying 100% current. IMO 30% isn't enough for a constant rpm rate hauling weight up a hill... you'd need to push or change the setting.

Then there's "start current". That determines how much current is applied on the first turn of the pedals. If you up that to 100% and keep current is 100% you'll fly like a rocket... and your battery will be cooked in no time at all. That's why you need to compromise. If you up all the settings just to get up one hill, you're draining your battery needlessly on the flats or when you're not hauling your kids around, and on start, you're wrecking your chain/cassette pulling that weight.

(Both "start" and "keep" are relative to "levels" typically 1-5 or 1-9 being set suitably too as a % of total). You could in theory set-up say levels 1-5 for max assist hauling kids up steep inclines with no effort, and levels 6-9 for sensible assist for when you're not and not killing your bike.

that does not solve the problem for his wife. Only a throttle can do that.
The OP can add a throttle to his M400/80Nm or any of Bafangs M range, including the M600/120Nm... Cheapies start from about £12 on Ebay. There's a separate tab to set-up how you want the throttle to perform in the UART App. CANbus BESST I don't know.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
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The Vogue is made by dutch people whom are know for flat surface and extensive ridding.
If that was my bike, I'd try changing the chainwheel first. Installing a smaller chainwheel has been suggested several times already, and by other members. For my particular bike, I tried 42T and 48T, before settling on 52T as best for both towing trailers uphill and speed over the flats. You probably should go slow when carrying kids around?


Then there's "start current". .....If you up that to 100% and keep current is 100% you'll fly like a rocket... and your battery will be cooked in no time at all.
And that's exactly what my bike did, during the brief time my motor was unrestricted. Sadly, I discovered it was illegal to have so much fun rocketing about. These days it zooms to 25km/h, at which point assistance rapidly diminishes.


Then there's "start current". That determines how much current is applied on the first turn of the pedal............................and on start, you're wrecking your chain/cassette pulling that weight.
My "Start current" was originally 20%, which made the bike jerky when pedal assitance started applying power - I can imagine this being useful offroad, to get the bike over tree logs , roche moutonnees and sleeping bears etc, but it made my small wheeled bike jump forwards, making U-turns and control difficult. Overall it was set up badly and I was on the verge of demanding a refund, but after changing "Start current" to 10%, and adjusting other parameters, my bike became a joy to ride.


(Both "start" and "keep" are relative to "levels" typically 1-5 or 1-9 being set suitably too as a % of total). You could in theory set-up say levels 1-5 for max assist hauling kids up steep inclines with no effort, and levels 6-9 for sensible assist for when you're not and not killing your bike.
I'd like "Start current" be completely independently assignable for each level, but it's not currently possible.


keep current is 100% you'll fly like a rocket... and your battery will be cooked in no time at all.
That's a very important consideration - I posted photos of the cells my 19.2Ah battery contains, and @Nealh kindly determined my battery is capable of discharging about 25A maximum continuous current. The OP's battery is only 13Ah, and cell manufacturer and type isn't mentioned... vague on the Vogue website.

All of my heavy trailer hauling was done when my controller had been limited to 15A, and it has never failed to drag a trailer uphill. I thought it might with one particular load, but my quick release rear axle got yanked out by that very heavily loaded trailer on the flat, well before I'd dragged it to the hill.


If you like the natural feel of torque sensing motors, you need a throttle to climb hills effortlessly.
that does not solve the problem for his wife. Only a throttle can do that.
One way to solve this could be inned to add a Throttle controller.
Your wife needs a cadence sensor like the BBS02 or a TSDZ8 with a throttle, both are capable of 120NM, to winch herself plus the kids up a steep hill without relying on leg power.
The OP can add a throttle to his M400/80Nm or any of Bafangs M range, including the M600/120Nm... Cheapies start from about £12 on Ebay.
Not as eye-watering as being guillotined by some dude smoking Gauloises wearing a onion necklace, but aren't fines for illegal ebikes eye-wateringly expensive in France? The OP should bear this in mind, and research the relevant local laws before deciding whether to install a throttle.
 
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Woosh

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May 19, 2012
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The OP can add a throttle to his M400/80Nm or any of Bafangs M range, including the M600/120Nm... Cheapies start from about £12 on Ebay. There's a separate tab to set-up how you want the throttle to perform in the UART App. CANbus BESST I don't know.
there are several threads about this on ES. Some people bricked their controllers because a) it's easy to make mistakes and b) the wire colours are not exposed at the connectors and OEMs may vary which wire goes where at the SM connectors. Bafang themselves change the wires positions in my batches, that's how I know after blowing up a few components myself. You have to check for ground and 5V with a multitester to be sure.
 

Saracen

Esteemed Pedelecer
Aug 24, 2023
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In view that you have hills and two/3 kids on the bike, you should consider a conversion with a stronger motor like the Tongsheng 48V TSDZ8 or 48V BBS02 capable to go up to 120NM. If you are in the UK, I can sell you a suitable road legal kit.

Is it 250watt ?
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
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Beds & Norfolk
yes, it is. He's got the standard 36V. The souped up versions run on 48V.
But neither a TSDZ or a BBS will fit a frame welded with an M400 mounting instead of a standard bottom bracket.
 

Woosh

Trade Member
May 19, 2012
19,790
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Southend on Sea
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But neither a TSDZ or a BBS will fit a frame welded with an M400 mounting instead of a standard bottom bracket.
agreed but the Vogue has a mere 36V 13AH battery. If you change the motor, you'll have to upgrade the battery. He could sell the Vogue to a stronger pedaller family and buy a Gazelle or another cargo bike and put a conversion on it or as in the example that I gave above, one already converted and for a good price too. That solves the problem in the long term. There are lots of electrified cargo bikes in and around Paris where they live.
 

AntonyC

Esteemed Pedelecer
Apr 5, 2022
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Surrey
A larger sprocket would be cheaper but mean losing that lovely chaincase, hence a smaller chainwheel. But most hub gears have tight limits on the torque they'll tolerate so if the gearing changes by much the Nexus could be shortlived (like mine).

I'd size up the road clearance of the centre stand to see how small a rim could be fitted to the rear. Not expensive and 24" and 22" would go one and two gears lower without straining the Nexus.

Then with a throttle and meter the motor's full output could safely be compared to what the torque sensor will release. If they differ a lot re-configure the controller or keep the throttle, otherwise change to stronger rear gearing or change the bike.
 

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