Question about motors

Goat

100 µW
Joined
Nov 25, 2022
Messages
7
Hi there so I'm used to riding a 2004 YZ 125 and I'm looking to build an electric Dirt bike in a YZ 250 2005 or other frame and I'm looking for similar power delivery and same power feeling as the YZ 125 I'm used to and I've seen the QS138 90H Liquid cooled and the QS138 V3 which would I be able to get to similar power (20-35HP) Continuous not Peak if that's even possible I'm looking to spend around $900-1000 on the motor alone, Sorry if this is the wrong place to put this
 
Lighteningrods

https://highvoltagekits.com/lightning-rods-electric-motors
 
Goat said:
(20-35HP) Continuous not Peak

You do realize that it takes about 30kWh battery for one hour at about 20kW motor output?
If you really intend to use 20kW continuous you probably need a motor that is rated somewhere close to 20kW continuous.
You probably get away with a little smaller because of the speed wind.
 
You could also go with a Ko-Moto setup,up 45kw with the Factory Edition,plus might be cheaper.
 
Thanks for the replies and recommendations, Saw a video by Electric Cycle rider ripping on a Freeride E-XC and it looks a lot faster than most of the QS138 bikes I've seen ridden on youtube would you be able to get the same power and speed as the Freeride E-XC if not a little faster with a Liquid cooled QS138 90H or QS138 V3? if not guess I'll look at the KO-Moto Purple F-Spec which I hope doesn't cost too much to import to UK
 
j bjork said:
You can be faster than a freeride with a qs 138 70h, so with a 138 90h there should be a good margin.
Water cooled wont be faster, but it will take more to overheat.

What's the difference between 70h and 90h if you don't mind me asking also has anyone done a QS180 bike yet? I did see one on here I believe but that caught on fire.
Also all of the videos I've seen on QS 138s the bike has been pretty slow but that could just be the riders not going very fast not the motor or battery setup think the fastest I've seen is likely Don cox or This build from another forum but that also caught on fire
https://electricdirtriders.com/threads/electric-rmz.1920/
 
j bjork said:
The difference is the magnet hight, I guess you could say rotor lenght as well.

Yes, there are at least 2 bikes up and running with qs180 here on the forum, my and dougf:s yamaha:s.
I dont beleve ither has been on fire..

Could've been a different forum or just not a 180, all I remember is they're also in UK and it burnt their garage down
 
j bjork said:
Maybe this with a 138 90H?

https://endless-sphere.com/forums/viewtopic.php?f=12&t=110469

That's the one, don't know why my mind thought it was a 180, also how's your 180 vs a modern 4 stroke 250? are you able to keep up or overtake on an MX track?

Edit: Also what is the offical store for QS motor I see cnqsmotors and QSmotors which is the actual site also which seller is the best on Aliexpress guessing it's the manufacturer SiAECOSYS but I see a few different stores on aliexpress with the name
 
My Surron tuned to 15kw can beat a Yamaha YZf250 in a drag race with the Ko-Moto Rs combo.It can go up to 37kw or 45 kw with the Factory Edition.Ko-Moto main support is in UK
 
I havent ridden much gas bikes, or mx.
But I would be very surprised if the bike wouldn't beat a 250..

Read the build threads, in dougf thread there are some drag race numbers that can be interesting if you can find something to compare with. There is some crazy drag racing in my thread too, not my bike though.
 
Hawaiiguy said:
My Surron tuned to 15kw can beat a Yamaha YZf250 in a drag race with the Ko-Moto Rs combo.It can go up to 37kw or 45 kw with the Factory Edition.Ko-Moto main support is in UK

Quite a bit of a difference in BHP per ton tho anyway, never knew komoto is in UK that'll make life easy also do you have any videos of your surron?

Think you'd probably be beaten by the YZF on track though
 
That is true,i don’t like going over 45mph in the dirt but on our tight trails the Surron rules,I’ve only managed 15 kw as any higher makes looping it almost certain.Ko-Moto has support from Uk and Usa,almost 24/7,they have a Discord channel that they monitor.Give them a call or email,you won’t be disappointed.
 
Hawaiiguy said:
That is true,i don’t like going over 45mph in the dirt but on our tight trails the Surron rules,I’ve only managed 15 kw as any higher makes looping it almost certain.Ko-Moto has support from Uk and Usa,almost 24/7,they have a Discord channel that they monitor.Give them a call or email,you won’t be disappointed.

Will do, I'll probably join the discord later tonight gotta find a suitable bike first (Currently looking at 2008+ YZ 250/450Fs) and then place an order for which motor I decide to go with that fits in the frame nicely depending on the bike I go with
 
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