Aprilia 125 rs conversion

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Jyby77   100 µW

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Aprilia 125 rs conversion

Post by Jyby77 » Nov 26 2020 10:27am

Hi,

I'm a new french biker, for the moment who love for the moment two stroke, and and most generally all things with mechanical and electricals technologies.
I'm driving :
- honda cb 400 N, my first motorcycle, my mom's motorcycle, renovated after 8 years of bad storage.
- aprilia 250 rs, my love,
- and a small one aprilia 125 rs, modified for racing, nearly 100 kg, with engine preparation etc... but without interest here

I'm completely noob regarding electric vehicles, but looking since 2 years about it, and more and more since few weeks by learning and reading many subjects of this forum.

The main lines of my project started to be clear so I think it's now time to explain your what I want, and time to have some help for sourcing some products, or to be help on some technical issues.

So my philosophy for racing is "light is right". I want to modify the 125 rs for racing, but amateur racing, so it's mean the first rule for me is to find lighter solutions on each point, but with a budget content :lol:
By amateur racing I mean one day of racing moments of 5 * 20min, or 6 or 7 * 15 min. I hope you see what I means

Motor : qs138 90h 4000w, seams to be the cheapper but reliable solution, same if my dream is EMRAX 188, but I've been understanding that this motor can reach probably a power near 40 kW with some adjustments on the rest of wiring, cooling, etc...
Controller : Kelly KDH12401E seem to be fine, but Nucular 24F can be also good and cheapper ?
Battery : Goal at 96V, LiFePO4 pack with reserve of current enought to find the limit of motor, 350A for max peak discharge? But no idea of the energy storage necessary for my use, just enough to keep small weight with theses technicals data
BMS : little bit lost, depending if batteries kit with BMS can be a good solution or not
Charger : linked to batteries pack and BMS

Goal for the motorcycle, keep under 100kg, with performances little bit highter than a 125 two stroke, and with max speed near 150 km/h. Budget is between 2000 and 2500€

What to you think about it, I'm in good way for this starting or I'm on the wrong track?

After a big description, sorry, some pictures of the motorcycle :
IMG-20190323-WA0012.jpg
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img_0032 (2).jpg (456.17 KiB) Viewed 1343 times
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Webp.net-resizeimage.jpg (428.58 KiB) Viewed 1343 times

SlowCo   1 MW

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Re: Aprilia 125 rs conversion

Post by SlowCo » Nov 27 2020 8:02am

Welcome, nice project!
Just a few thoughts: LiFePo4 is a great chemistry but too heavy per kWh for racing I think. Better choose Li-Ion high discharge cells. You'll probably will need to build 2 (or 3) battery packs that you can exchange after a session on the track and charge one pack while racing with the other. You can search a few projects here on E-S and determine how much kWh of capacity you'll need to race 20 minutes.
The Nucular controller seems to be the best and most user friendly controller for home built projects.

I hope more knowledgeable people will find this thread also but you posted in "E-Scooter and Motorcycle Photos & Videos" where the "E-Scooter and Motorcycle General Discussion" section might get more views.
User "jonescg" has a very interesting thread and a lot of knowledge on building electric race bikes. Maybe post your questions there also or contact him with a personal message: viewtopic.php?f=10&t=29916&start=1250
He also builds special "racing battery packs" out of pouch cells:viewtopic.php?f=31&t=38252&start=575
Good luck and enjoy building!

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Dui, ni shuo de dui   10 kW

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Re: Aprilia 125 rs conversion

Post by Dui, ni shuo de dui » Nov 30 2020 1:47am

Salut, la forme? Bienvenue sur le forum cher compatriote!

For the best possible performance, LiPo would be the best, because they are much lighter, they have a really high discharge rate and they occupy far less space.
That being said, LiFePO4 isn't that bad, some of these have a great discharge rate too, plus they are safer to use and they last much longer.

So it all depends on how competitive you want your bike to be.

For racing, in my opinion, a 4000W QS might be a bit short. I would go for the 8000W version at least, racing on circuit is much more intensive than street racing so even though these motors can bear a lot more power than advertised, they probably can't do that for a whole race where they are continuously under load. When used on the streets there are stops, red lights, etc, so the motor can cool a off a bit, this doesn't happen on a racetrack.

About the controller, in my opinion, at least on paper, the nucular even in its most powerful version sounds a bit weak to me. I think you should go for at least 500-600A battery peak discharge and 600-800A per phase. I know one controller that is capable of that kind of power, but it is a chinese brand and I do not know if this is available outside of China. Kelly, Mobipus and APT also have controllers in that range of power.
I don't know why you mentionned the Kelly KDH12401E since this controller is designed for brushed motors, it will not work with a QS Brushless DC motor.

BMS: the ANT BMS is still the best choice so far, the only thing that sucks is that it doesn't come in an enclosure but aside from that it's almost perfect, and it is real cheap. Maximum 32S.

Charger: there are lots of choices, but keep in mind that charging quickly will damage your battery, so better choose a slow charger if you don't bother waiting.

I'm not sure what are the prices in France these days for that kind of hardware, so I can't really say if 2500Euro is realistic. If you already have the bike then maybe, otherwise if you have to purchase the bike then I don't think so.
:bolt: New Build in Progress: Electric Roadster, 30 000W Kelly KLS72701, 24S2P A123 cells :bolt:
viewtopic.php?f=12&t=109246

:bolt: My electric Ninja 250 clone: 16 000W Sabvoton 72200, 23S2P A123 cells : :bolt:
viewtopic.php?f=12&t=90032

:bolt: My electric Scooter: 11 000W Sabvoton 72150, 72V 50Ah LiFePO4 cells: :bolt:
viewtopic.php?f=12&t=75912

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Nov 30 2020 4:05am

Thanks a lot to you two, I'm really a noob, and I haven't seen that Kelly KDH12401E was designed for brushed motors.

Problem for 8000W motor is that it's not available like mid drive motor but hub motor, and it's not possible for me for racing, because gyroscopic energy is a problem. I have seen an old version who was qs 171 100h, but not longer available. So if I want a mid drive motor with more power, but light, I need to find another brand.

I have also seen this one but not available :
http://www.cnqsmotor.com/en/article_rea ... r/875.html

Sometimes I think that no motor existing for my project ^^ not a lot of alternative between small power like 20kW max, and bigger power like EMRAX 188.

Like said by SlowCo, if an administrator can change the place of my thread into "E-Scooter and Motorcycle General Discussion" section? It can be helpfull, sorry for that.

For 2500€, it's without the motorcycle, I have it, it's this one on pictures.

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Nov 30 2020 4:30am

My next motor solution can be the ME1507 but more expensive. I don't find intermediate motor between qs138 90h and this one, who is reliable.

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Dui, ni shuo de dui   10 kW

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Re: Aprilia 125 rs conversion

Post by Dui, ni shuo de dui » Nov 30 2020 5:39am

Jyby77 wrote:
Nov 30 2020 4:05am

Problem for 8000W motor is that it's not available like mid drive motor but hub motor, and it's not possible for me for racing, because gyroscopic energy is a problem. I have seen an old version who was qs 171 100h, but not longer available. So if I want a mid drive motor with more power, but light, I need to find another brand.
Ah ok sorry I thought you were going for a hub motor, didn't pay attention it was a mid drive.
In my opinion gyroscopic effect isn't really an issue, most people overestimate the effects mostly because they read stuff and get an opinion before even trying. Here in China they are racing with hub motors and still get very decent lap times, I ride everyday with a hub too and it never prevented me from taking tight corners or riding like a maniac. :lol:
But I'm no pro rider and never participated in a competition, so you probably know better, just don't close a door if you're not absolutely certain.

A hub would give you much more space to work with, I think you can forget lifepo4 if you want to go mid drive, you just won't have the space for it and your only option will pretty much be LiPo.
:bolt: New Build in Progress: Electric Roadster, 30 000W Kelly KLS72701, 24S2P A123 cells :bolt:
viewtopic.php?f=12&t=109246

:bolt: My electric Ninja 250 clone: 16 000W Sabvoton 72200, 23S2P A123 cells : :bolt:
viewtopic.php?f=12&t=90032

:bolt: My electric Scooter: 11 000W Sabvoton 72150, 72V 50Ah LiFePO4 cells: :bolt:
viewtopic.php?f=12&t=75912

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Nov 30 2020 5:47am

I should be able to test a motorcycle with hub motor but it's not easy to find on racetrack ^^. So It can be an option but the last one, I continue to search in first.
Problem with many motors is the lack of return from people who try to push it, to know the real resonable maximum.
For sure for the battery I trust you, it's clear, LiPo

Xtr6   100 W

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Re: Aprilia 125 rs conversion

Post by Xtr6 » Nov 30 2020 11:38am

I did a conversion with a Motoenergy M0913 controlled by a Sevcon gen 4 size 6 and this was something that would be usefull for your purpose. Another motor is the Heinzmann pm120. It is the same as Zero used. I have one on a trailmotorbike. It is verry light and has smal dimensions. The altra motor should also be an option for you. There is infact one for sale at this moment. I have a Nucular 24F on the Heinzmann and this is really a good combo. Best is the sevcon but this is to sofiticated to programm. I have a sevcon on a Heinzmann pm 100 and this is really a roadrocket, the main reason for a s small motor is more space there is for battery.

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Dec 01 2020 3:59am

Hi Xtr6,

Thank you for your feedback, I'm very interested by this combo of pm120 and nucular 24F. Do you think that max power can be exceeded? Do you have a temperature monitoring when you are riding hard with it? Because finally it's not very far from qs 138 90h performances.

I have looked the thread of jonescg, and it's beautiful project but we don't search the same things ^^ I prefere to stay under 100kg, to race on small racetrack (not Le Mans or Castelet etc...), and keep a power near a normal 125r, or little bit higher, like 30kW would be the first goal, for 15 - 20s in a straight line but overtake the big thermics motorcycles in the turns :twisted:

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Dec 01 2020 4:08am


SlowCo   1 MW

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Re: Aprilia 125 rs conversion

Post by SlowCo » Dec 01 2020 8:09am

Try to find a Zero motorcycle with front end damage on a junkyard to harvest the motor and controller etc. That way you can get more power for less money.

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PITMIX   100 W

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Re: Aprilia 125 rs conversion

Post by PITMIX » Dec 01 2020 11:41am

Hi, Salut Jyby, I see you are going to tackle something difficult and very expensive. Your budget is certainly too low. That's hardly what it takes to make a 10kW motorcycle for fun. A 30 or 40kW project for racing on the circuit, not to mention the engine, you will need at least a battery of 5000 € to be able to power this engine and hold several laps.
Aixam 550 Twin retrophite Qs 138 70H, Thermo-Nucular electronics 24F, LG Chem 20s 60Ah

Xtr6   100 W

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Re: Aprilia 125 rs conversion

Post by Xtr6 » Dec 01 2020 1:28pm

I did run the Heinzmann with the Nucular in the sensorless mode and it performed verry nice, but with trail there is a lot of power from zero speed and thats the reason why I mounted Hallsensors. The Heinzmann has a sin/cos encoder that will not communicate with the Nucular. You van make 25 Bhp from this combo If you have a good Battery, This is as mentioned a verry important statement that there is a big cost in. Invest in a good battery with almost no sag and you will achieve youre goal. I have a spare Heinzmann brandnew let me know if you are interrested in it. I also have the File for the sevcon for this motor. But to be honest sevcon is a pain to programm.
Or go like Slowco said, look for a damaged Zero bike

Pentti M Reku   10 mW

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Re: Aprilia 125 rs conversion

Post by Pentti M Reku » Dec 01 2020 2:43pm

You can find batteries with decent performance in some hybrid vehicles. They are not most energy dense in wh/kg sense, but will put out plenty of power for a price thats hard to beat.

BMW hybrid packs with Samsung cells come to mind. 5-6 modules of 16s in a pack, 1,5kwh rated capacity (2kwh in later models) each module, ~13kg each, so about 120wh/kg. In original application they put out ~14kw of peak power each. Prices in ebay have gone to shyte lately, but people have bought 6 module packs for less than 1000 euros elsewhere.

Other similar performance packs could be found from Opel Amperas, Volvo hybrids etc. I think member j bjork here used few modules out of a VW pack with cylindrical cells? Those might be better in energy density.

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Dec 03 2020 7:13am

Thanks to hall of you. I have had somes importants informations.

@PITMIX, it's clear that it's not easy ^^ but my goal is pleasure racing but not race. And effectively budget will probably increase a little bit.

I will search more feedback from equivalent of motors like qs138 90h, or little bit bigger to seen how many kW can be reach for few second with modifications for cooling etc... or try to find money for for ME1507

Another item is to try to have lighter motorcycle in parallel.

I keep you informed after christmas but one thing is sure, my 125 will be elecrified.

SlowCo   1 MW

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Re: Aprilia 125 rs conversion

Post by SlowCo » Dec 03 2020 10:13am

Jyby77 wrote:
Dec 03 2020 7:13am
I keep you informed after christmas but one thing is sure, my 125 will be elecrified.
Biggest "problem" is cost. It will be expensive to have enough battery packs to be able to race multiple sessions on a day. For your budget you'll probably be able to build one small battery pack capable to ride 1 short session. And then you'll need to recharge. Racing requires a lot more energy then normal street riding.

This is an informative thread: viewtopic.php?f=12&t=103800

j bjork   10 kW

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Re: Aprilia 125 rs conversion

Post by j bjork » Dec 04 2020 1:20pm

I think a qs 138 90h would be a lot better than a similar rated hub.
From my experience the qs 138 70h "3000w"can take a lot more than a qs 205 50h "3000w" hub, even with statoraid and hubsinks.
The hub would get over 100 degrees C after maybe 15min of trail riding, while the mid drive is usually not over about 70 degrees on a bike twice the weight and a lot more difficult trails.

That may not mean that the 90h is enough for you, but I think you will need a higher rated hub for them to be similar in performance.

Jyby77   100 µW

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Re: Aprilia 125 rs conversion

Post by Jyby77 » Jan 08 2021 5:59am

Thanks to everyone. I have tried to compare preformance of 125rs and converted motorcycle with qs138 3000W and it's not so bad
0-100 near 6s
vmax between 140-160
I will wait some peoples who have projects with qs138 90h 4000W to see the result and I will see after.

@PITMIX, qs138 90h in your car seems to have enought power and tork for a big weight no?

What to you think about this video :
https://www.youtube.com/watch?v=kc38vocDwgE&t=621s

same if speedometer isn't right, it seem not so bad

boars   100 W

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Re: Aprilia 125 rs conversion

Post by boars » Feb 03 2021 9:35pm

Nice choice of bike to convert, they're super light weight, it's crazy. :thumb:

I picked up a RS125 myself last year that was already converted then sort of left about and never road registered as it was built as a university project.
The batteries were pretty average and only 42V from my understanding.

Next owner/s planned on upping the power and putting in better batteries to get it going properly but never got around to doing so.
It sat in sheds/garages etc for probably 4 years or more so I bought it with the intention of getting it done myself.

I'm clueless though so I've enlisted the help of a local electric conversion shop to get me over the last hurdles and onto the road.
Not doing anything too fancy just upping the voltage and pack size with some lipos to 72V and attempting to get it registered so I can potentially commute on it. Waiting on parts is killing me though - shipping from some places has seemingly gone to hell since COVID!

In the meantime I'm riding my mito 125 and an old custom RZ250 - love 2T! :thumb:

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