GSM Mid Motor Controller

[awol]

I've just spotted the 250w GSM mid motor on Woosh's website. Is says without controller.
Is there a special mid motor controller needed? or could I use my usual KT controllers from PSWpower or BMSbattery ?
If so what would be the max amps this motor can take at 36v for a short time setting off moving?
Has anybody any real life torque comparisons against a hub motor like a Q100h or 250w Bafang CST ?
I would not be bothered about speed more slower torque when setting off, how does the torque compare with the tried and tested BBS01 250w?

 

[Woosh]

or could I use my usual KT controllers from PSWpower or BMSbattery ?

yes.

 

[anotherkiwi]

I've just spotted the 250w GSM mid motor on Woosh's website. Is says without controller.
Is there a special mid motor controller needed? or could I use my usual KT controllers from PSWpower or BMSbattery ?
If so what would be the max amps this motor can take at 36v for a short time setting off moving?
Has anybody any real life torque comparisons against a hub motor like a Q100h or 250w Bafang CST ?
I would not be bothered about speed more slower torque when setting off, how does the torque compare with the tried and tested BBS01 250w?

You haven't been reading my threads! ...

1. You need a controller with a connector for external speed sensor (of course).
2. I had issues finding a correct setting for the internal PAS, it would kick in when turning the pedals in both directions. Fried the PAS HAL so am using external KT 12 magnet PAS
3. I haven't tried upping the Amps only voltage to make the motor spin slightly faster. I had back EMF cutting the power because I was spinning too fast, 44.4v 12S solved that problem.
4. You need a big beefy battery with this motor, even if you are only using 15 A. I don't know where this comes from, maybe the motor spins up much faster than a hub motor so draws full Amps almost immediately and weeny batteries don't like that. No problems with LiPo but I would definitely chose a high discharge 18650 cell based battery with a 20 A BMS.
5. I have real life torque comparason with a Mxus XF08 and like all mid motors you get more torque than you need when you are in the right gear. It comes with a 46 tooth chainwheel which might be OK with a 26" wheel (haven't tried yet), I would suggest a 44 tooth with a 28" wheel. Better still a spider and two chainwheels to cover all needs from +20% gradients to cruising at 45 km/h on the flat. All BBS01 spiders are compatible.

More questions just fire away.

 

[awol]

You haven't been reading my threads! ...

AK I have, in fact it was partly you mentioning the GSM in the past that made me go looking for it earlier and I found it at Woosh. The forum didn't let me search GSM (too short). I came across an old thread talking about an internal controller and any other controller mentioned I was not sure whether they were special mid motor types of the same hub equivalent. I will be reading through your 'number 2' thread tomorrow again, taking more notice since I am now looking at the same motor. I need a cheap'ish build this time - those BBS motors are a bit to expensive for me at the moment and I have controllers+parts and LCD's left over from past projects it seems I can use.

 

[anotherkiwi]

I would say the sweet spot for power/torque @ 36v would be the PSW power 17 A controller. The initial testing by Trex was with 48v and a 20 A controller IIRC. I have never managed to warm the motor beyond tepid in 2000 km and you know where I ride

I have found a huge CPU heat sink in my computer bits box and will be fixing my 15 A KT controller to that and try pushing 44.4v through it. That is about 735 W peak with battery hot off the charger (or >550 W at the wheel in d8veh's money), plus my 150 W so not far from the mythical 1 HP.

I will be running 48-32 chainwheels and sticking to the wide range 8 spd 11-40 Sunrace cassette on the trike at the beginning. Upgrades at both ends could be going to a 10 speed 11-46 and a 50-34 compact road chainwheel. The granny gears are really just for "get home safe and sound" usage but as you get on in age you like having a "B" plan

 

[Nealh]

My 29E didn't like the GSM and it suffered with range after, admittedly I use the GSM unrestricted and @ 36v 29 mph /46km/h was doable.
Kirstin also had issues with his 29E after using the GSM.

 

[awol]

My 29E didn't like the GSM and it suffered with range after, admittedly I use the GSM unrestricted and @ 36v 29 mph /46km/h was doable.
Kirstin also had issues with his 29E after using the GSM.

I wonder if that was the controller being a bit too abrupt with the initial acceleration amps, as I've an S06S which brings in the initial power more gently than a KT controller I have.

 

[Nealh]

I wonder if that was the controller being a bit too abrupt with the initial acceleration amps, as I've an S06S which brings in the initial power more gently than a KT controller I have.

Could well be but can't say for sure as I didn't have a watt meter wired up.
SO6S is a KT unless of course BMSB have customer KT software.

 

[awol]

Better still a spider and two chainwheels to cover all needs from +20% gradients to cruising at 45 km/h on the flat. All BBS01 spiders are compatible.

I think 46t chainring will be too big for what I would need, I think for what I will do I need 42 or maybe smaller so to re-use the existing 42t chainring is this the sort of thing I need, or is there better
https://www.ebay.co.uk/itm/104BCD-Chainring-Spider-Adaptor-Gearing-for-Bafang-8Fun-BBS01-02-Mid-Motor-Ebike/253664047442?hash=item3b0f8e3152:g:8tgAAOSwpNxap3Nh
also how have you got a double chainring fitted on the motor?

 

[anotherkiwi]

http://precialps.com/uk/chainring/9-chainring-bling-ring-42t-bafang-bbs01-bbs02.html

I have this one http://precialps.com/uk/accessories-bafang-bbs01-bbs02/7-adapter-spider-bafang-bbs01-bbs02.html it comes in an envelope with a normal tarif stamp on it. Did I say it was light? And it has mounting positions for inner and outer chainring.

Changing at the moment is a stop, get glove from panier, change chain from one ring to the other affair. For the trike I will use a Sora front derailleur with a home made derailleur extender and change from the bars like everyone else.

If you are healthy and have 28" wheels a 44 will be the best option with an 11-34 cassette. If you have 26" wheels the 44 will be perfect. I find the 42 a touch too low but then I have a 32 for the gnarly stuff and quite strong legs.

Now for the single speed options you have Alligt https://www.dutchbikebits.com/alligt-chainrings-60bcd?keyword=alligt&category_id=81 who make all the sizes no one else offers.

 

[awol]

I have this one http://precialps.com/uk/accessories-bafang-bbs01-bbs02/7-adapter-spider-bafang-bbs01-bbs02.html it comes in an envelope with a normal tarif stamp on it. Did I say it was light?

I like the look of that one, non in black in stock at the moment though, will have to consider it in the future. Motor is ordered so will be looking at all this gearing soon.

 

[awol]

Motor is fitted and I definately need to change the front chainring for a smaller one. I also need to move the chainline inwards about 5mm somehow.

How do I get the chainring off as I can't see how to remove the black plastic chainguard and don't want to break it.?

 

[Woosh]

the chain guard is the same on the Bafang BBS.
If you want to remove it, unscrew the 5 small self tapping screws at the back of the chainring.

 

[anotherkiwi]

Motor is fitted and I definately need to change the front chainring for a smaller one. I also need to move the chainline inwards about 5mm somehow.

How do I get the chainring off as I can't see how to remove the black plastic chainguard and don't want to break it.?

42 tooth blingring would probably do that. I think 44 is the sweet spot on flattish roads say up to about 9% gradient. Once you get over that the double chainring is the weapon of choice.

My chainline is horrible but the chain falls off onto the inside chainring when I forget I shouldn't be changing gear on bumpy terrain. It will depend on your frame I guess.