QSMotor 4000W V3 17” Hub Motor Aprilia RS50 Conversion

[Dui ni shuo de dui]

Thanks for all the feedback I’ve received which I’ve taken onboard and changed my controller and also revised the batter pack spec.

I’m sticking with the QSMotor 4000w v3 but switching the controller to a Sabvoton SVMC72150 / 150A battery amps with TFT display and bluetooth (the issue I missed on the Kelly KLS controller was that the Amp figures quoted were motor / phase amps). I’ve got contacts in the UK who are reliably running this controller on an Enduro Frame eBike set up using the QSMotor 205 3.5t hub motor at 150A battery power and achieving 90mph+ I know there are some comments out there about newer Sabvoton controllers being unreliable but everything I’ve seen on builders using them in the UK is that they’re proving reliable.

I love the Sabvoton and in my opinion this is the best controller I tried. But I think you could have gone with the 200A version. I have installed a 150A sabvoton on my bike earlier, power was ok but not really insane, our bikes are heavy. Now I'm using the 200A one and it's much better.
Also, I've heard that the recent Sabvoton are not as reliable as they used to be, this has been said by several members on the forum. So let's hope that they corrected the new versions.

For the battery I’ve decided to invest in a new high power Lithium Ion pack using Samsung Q30 cells - 72v 40Ah with a smart BMS and which can put out 160A.It should give me a decent range at the average speeds I will be going, plus it will easily fit in the Aprilia frame and weighs less than 15kg. I’ve selected a UK builder for the pack at a very reasonable cost and they’ll provide a 12 month guarantee - the also guarantee genuine Samsung Q30 cells.

I’ve also sourced a new Aprilia RS50 swingarm to modify which will allow me to set the motor up off the bike, test everything then fit it to the bike.

Will include some pictures once all the parts start arriving

Seems adapted to a 150A controller, so you shouldn't have much trouble. Just be aware that li-ion cells tend to lose their capacity faster than LiFe cells, especially at high current draws.

 

[swiftyds]

Thanks for the feedback - I had the same comments back from Robert at QSMotor about 150A being a bit small so we’ve upgraded the order to the 200A version

 

[ridethelightning]

look at better cells. 30Q have shown to have fast capacity loss.
see es thread somewhere..
i have some 30Q packs, wont be using them again. oh and dont be fooled, they are not really 3ah, more like 2.6-2.8ah on a good day
id be looking at some cells from es vendor tumich, id go for vtc6.
it will be maybe more initial otlay, but will pay off long term.

i did a build with sabvoton 200A controller. blew up almost imediately. garbage...they use very cheap fets...~usd $0.7each

 

[swiftyds]

Thanks for the heads up on the Samsung 30Q cells - I’ve looked into these more and I can see how they aren’t great at holding charge if you zap them at much more than 2C.

I’m really struggling here to find something that is relative safe (not Lipo), close to being reasonable cost (not Graphene) and that won’t wreck itself at the high levels of A discharge I’ll be pulling given this is a e-motorcycle rather than an e-bike.

I’ve gone back to first principles on this and started looking again at high density/high rates of discharge LifePO4 cells.

I can’t get the US based pack that was posted in an earlier reply as they won’t ship to UK, and I’m hearing the cells in the Valence Power-u-charge module aren’t up to the rates of discharge I’m going to need.

So I’ve sort of gone a bit old school and thinking of building my own pack using Headway 38120S or HP cells - I can take the space these will occupy given the huge frame size i’ve got with the Aprilia and if I go with HP cells I understand I can get 150A out of these reliably.

I’ll throw this option out there now .... what do you folks think?

 

[ridethelightning]

id considder vtc5a cells, 35Apeak, from tumich. shipping is cheap but may take a little time(takes ~60days to aus) i just got some.ask for bulk discount.he has a good price.
https://endless-sphere.com/forums/viewtopic.php?f=31&t=61608

he can also underdeclare them to avoid taxes etc.
otherwisw id be looking at newish salvaged tesla packs,or other ev packs(not leaf) monstar sells them sometimes,they are becoming more common in eu now.

-id skip headways, or other lipo4 ( except A123,) they just sag like a big ol mumma

-if you can build a large enough pack, the discharge rate becomes less critical.
600 *18650 would be a good start figure for the type of bike you are building, vtc5,vtc6,tesla p100d, panasonic...

 

[swiftyds]

I’ve decided to build the Aprilia up first using some small LiPo packs that whilst they will only give me a small range it will be enough to get the bike up and running and the registration changes made. I can then also better see what the Amp draw is on the battery pack for the speeds I’m designing this to do.

I will then have a better idea on spec etc for the pack. What it’s clear is that to do 100A draws off Li-Ion cells (any make/model really) I will need to build an overall pack around 50Ah so that I’m doing no more than 2C on a regular basis from the cells.

For the LiPo short term solution I will fit alarms on each pack and monitor the A draw from the overall pack to make sure I don’t get anywhere near the LVC. I’ve also managed to source a Zivan NG3 charger for the LiPo pack which will be 16 5S packs at 5A/20C configured as 4 series / 4 parallel, so 20s4P in effect and 72v 20ah.

 

[swiftyds]

Motor and controller turned up at the end of last week. I must say I was very impressed with the whole experience dealing with QS Motor (Robert Chen) and the great packaging. Everything looks good quality as I took it out of the boxes.

In the end I went with my original choice of a Kelly KLS 7275H for the controller with Bluetooth adapter so I can program on an Android tablet/phone.

I’ve had plates 3D printed (many thanks to Manny for sharing with me his Fusion 360 files) for extending the swingarm width - these look a good fit and once I’ve cut the swingarm I will get these waterjet cut by a local company.

 

[swiftyds]

The build has finally begun after collecting all the parts together.

First off I got a battery box fabricated to hold the LIPO packs (16 packs, giving a 20s4p configuration).

It’s a bit of tight fit but there’s sufficient space for the busbars linking the packs together with appropriate insulation.

I’ve also sourced a tyre and used the cable tie method to get this onto the hub motor rim, and then removed the valve core to use a couple of good blasts of compressed air to seat the bead of the tyre all the way around the rim. Seems to be seated OK and holding pressure fine. I can recommend using a Black and Decker workmate bench for mounting the hub motor rim on to make this a lot easier!

Now I’m all set to modify the axle mounting points of the swingarm itself. Many thanks to Manny for sharing with me his Fusion360 CAD files for the plates that he had fabricated for his Aprilia conversion. I had these 3D printed first and made a number of modifications before getting them laser cut and drilled which was a cheaper option that waterjet cutting.

Here are the 3D printed versions in the swingarm cut out.

Oh and I suddenly realised I’ve not actually posted any picture of the donor bike that I’m using here.....

 

[tylerwatts]

Hi. Really like where you were going. Any updates on your build?

Cheers
Tyler

 

[swiftyds]

Apologies for long overdue update ... got the motor / controller/battery all set up and configured off the bike to sort wiring out etc.

Then just after Christmas started in earnest modifying the Aprilia swing arm to fit the QS Motor. I knew the width of the swing arm would be tight but the design of the plates I’d had made up for the mounting the axle/axle flats gave me another 150mm each side of the swing arm. All looked OK until I came to fabricate a mount for the rear brake caliper .... then it became very apparent there was never going to be enough room on the brake disc side of the swingarm to mount the caliper and get enough clearance.

I wanted to avoid cut/welding the swingarm so eventually had to make the difficult decision to abandon the Aprilia as the donor bike and look for something with a bigger frame/swingarm. After some searching I was able to offload the Aprilia and found another donor bike.

It’s no where near as well built as the Aprilia but it’s a bit more suitable for what I’m doing here ... a Yamasaki YM50-RE!

I will now close this thread and start another thread documenting the build of the eYamasaki!

 

[tylerwatts]

Ok thanks. Shame about the RS, I would have just suggested swapping the swing arm. I did it many times on ICE bikes and that's more hassle aligning chains etc. Just need the correct frame width.

Anyway I look forward to your Yamasaki build.

Cheers
Tyler

 

[swiftyds]

Went through that process first Tyler but the swing arm pivot dimensions for the Aprilia meant there wasn’t a lot of options for using another swing arm

 

[tylerwatts]

Fair enough, didn't mean to be rude or anything. I look forward to your Yamasaki build.

Cheers
Tyler

 

[Dui ni shuo de dui]

Oh that's really bad news, the Aprilia looked awesome....
Looks like the swing arm was made of steel, so it should be easy to modify. Maybe if you descibe the issue you have with your brake caliper we can help you figure out a solution. I'm sure we can find some way!

Also, did you consider the fact that your motor can act as an ebrake, so that basically you don't really need a brake in the first place?
You'll still technically need a brake just for good measure in case something goes wrong with the motor, but its not nearly as critical as it would be with a gas engine, so that could be replaced by a weaker/smaller system, whatever could fit.

 

[swiftyds]

Fair enough, didn't mean to be rude or anything. I look forward to your Yamasaki build.

Cheers
Tyler

No worries Tyler - all feedback / responses to my posts are welcome and taken on board positively.

 

[swiftyds]

Oh that's really bad news, the Aprilia looked awesome....
Looks like the swing arm was made of steel, so it should be easy to modify.....
Also, did you consider the fact that your motor can act as an ebrake, so that basically you don't really need a brake in the first place?

Thanks for the input - I have to say I was gutted when I discovered the tolerance on the brake disc wasn’t there to mount the calliper. As I’m in the U.K. and want this road registered it needs to pass an MOT once converted which tests brakes (front and rear) so needs to be equivalent in terms of efficiency as the original petrol engine bike.

I did get a bracket made up to mount the calliper off the swingarm box section (rather than being mounted of a bracket through the axle) but there just wasn’t enough of a gap between the disc and the swingarm box section itself.

I did look into having the swingarm widened, as you say it is just steel, just the DVLA in the U.K. are tightening up on e conversions and if they see significant mods to the frame, including swingarm, they are claiming it’s more of a conversion and you need to go through an MSVA test.

 

[Shazzy]

Motor and controller turned up at the end of last week.

Did you pay customs and duty?

 

[swiftyds]

Yes - ended up around 15-20% of actual goods value in total if I remember correctly.

 

[tylerwatts]

Have you started a new build thread? I can't seem to find one.

Cheers
Tyler

 

[swiftyds]

Posted earlier today .... https://endless-sphere.com/forums/viewtopic.php?f=12&t=105463