crf450r 45kw race bike build

[rivvs]

Decided to show you my new bike build. My first one did not go has planned but I learned from it and ready to build version 2.0.
The first bike: https://endless-sphere.com/forums/viewtopic.php?f=12&t=110469
The rmz felt a little slower than a 250 four stroke dirt bike. For this one I want 450cc type of power.
Here are the specs:
2021 crf450r
Qs180 90h motor With reduction chaincase but this time in an oil bath because on the other bike the chain was getting hot.
Fardriver ng961800
6.4 kwh battery made of Molicel P28A in 26s24p configuration with immersion water cooling. The battery will be build the way I build the first one but this time I will not bypass the BMS.
I have learned how to CAD and also now have a 3d printer for testing parts before making them in aluminium.
I started by 3d printing the motor to decide where it was going in the frame.


Printed motor mounts


Then made the battery box using foam board




Then desingned everything in cad drawing


I am now starting the machining of all the parts.

 

[j bjork]

This looks like a really good start :thumb:

It is a nice change they did on the rear cover of the motor with the exit of the wires.
I wish they could have kept the front cover with the relative flat surface though.

What sprockets do you plan to use, and how will you tighten the chain?

 

[rivvs]

This looks like a really good start :thumb:

It is a nice change they did on the rear cover of the motor with the exit of the wires.
I wish they could have kept the front cover with the relative flat surface though.

What sprockets do you plan to use, and how will you tighten the chain?

Im using a 11 tooth 428 size for the motor side and 16 or 17 on the jack shaft. The will be a chain tensioner in the chaincase like on a snowmobile.

 

[j bjork]

Alright, have you found available 11tooth sprockets or will it be custom made?

 

[rivvs]

Alright, have you found available 11tooth sprockets or will it be custom made?

I bought 17 tooth JT sprocket that have the right spline and I will be turning it on the lathe just to keep the spline and weld to 11 the other 11 tooth sprocket.

 

[speedy1984]

Project looks awesome and will be watching along the way :thumb: I like the idea of immersion cooling but never actually seen this done.Is there a cooling product you have in mind for use on your build?Ive built a 2010 crf450 138v3 bike for more hard enduro use so bursts of power not mx track power type needed here.Im yet to build the pack so very interested buddy.

 

[rivvs]

Project looks awesome and will be watching along the way :thumb: I like the idea of immersion cooling but never actually seen this done.Is there a cooling product you have in mind for use on your build?Ive built a 2010 crf450 138v3 bike for more hard enduro use so bursts of power not mx track power type needed here.Im yet to build the pack so very interested buddy.

I will be using ampcool coolant.

 

[speedy1984]

Holy sh.t its actually pretty costly tb and the 3m stuff is way more still!I do think for how easy it could be it may well be the best simple option for cooling though.

 

[summenerunknown]

Would you be able to share the resources you have used to learn CAD and 3d printer design?

 

[rivvs]

Would you be able to share the resources you have used to learn CAD and 3d printer design?

I learned it by tryal and error. And when I did not know how to do something I watch videos on youtube.

 

[SlowCo]

Very nice project :thumb:

 

[stan.distortion]

Would you be able to share the resources you have used to learn CAD and 3d printer design?

The YZ250 build thread also has a 3d print of the same motor, not sure if the file is shared in the thread:
https://endless-sphere.com/forums/viewtopic.php?f=12&t=109878

 

[rivvs]

Update
Since I bought the frame on ebay It did not come with the subframe so I had to make one.
I used the subframe from my 2021 crf250r wich is the same frame to make a jigs.

The machined pieces and made it wider so the controller can fit.



Juste need to finish welding.
Next I mounting the motor.

 

[E-Andreas]

Hi Rivvs,

nice motor.
I was wondering if i can get the drawing (and maybe specs) of the motor as i can´t find any detailed information online.
Thanks
Regards
Andreas

 

[TysonScott]

can you explain why you use gear reduction with this motor? i saw the other build where the guy also did one. Why not just have a direct drive to the rear wheel like most qs138 builds?

it seems like it takes up alot of space and adds weight.

 

[rivvs]

can you explain why you use gear reduction with this motor? i saw the other build where the guy also did one. Why not just have a direct drive to the rear wheel like most qs138 builds?

it seems like it takes up alot of space and adds weight.

Because for the bike to handle correctly and the suspension work freely it needs the sprocket at the right place close to the swingarm. The only way to do this is wih gear reduction.

 

[BenBenBen]

can you explain why you use gear reduction with this motor? i saw the other build where the guy also did one. Why not just have a direct drive to the rear wheel like most qs138 builds?

it seems like it takes up alot of space and adds weight.

Because for the bike to handle correctly and the suspension work freely it needs the sprocket at the right place close to the swingarm. The only way to do this is wih gear reduction.

For information, I talked with the guy from QS motor in China today. He told me that they made a "prototype" of the QS138-90H liquid cooled equipped with a integrated reduction like the 70H V3 (something like 1:2.37) and they think about mass production in the future for this setup. Could be a great compromise Power / Torque / weight / volume / cost / sprocket position.

But for the moment, it's a fully machined prototype that they sell about 6kUSD... Got to wait

 

[j bjork]

Sounds interesting, I wonder how wide it will be..

 

[BenBenBen]

Don't know, asked for a CAD but he told me he didn't have it

 

[BigBlock]

Immersion cooling battery technology is very cool.
Can I ask if you did it before ?

I have several experience of immersion cooled battery packs and they are quite complex to design and manage properly. For sure not possible for the average DIY builder.

Also I wouldn't advice for a MX bike where vibrations will make very hard to fully seal the battery enclosure and avoid leaks.

At least for my experience.

 

[BenBenBen]

We got guy doing a cool concept in France
Here a link. https://e-mersiv.com/fr/accueil/

Probably a lot too expensive for any single bike conversion, but maybe inspiration to take. They do not only use the loquid to move the heat out to a radiator and dissipate, they use condensation effect to create cold.

But personally, I wouldn't go for liquid neither. Too heavy, and too much leak risk.

Also you can't plunge the fuses in a bath cause they are not rated to be cooled! So you got to forget about cell level fuses. And even all other fuses that could be in the main enclosure cavity (power, charge...)

And finally, during the test period where you can have to open the pack to check or modify stuff, it can be a real pain!!!

If strong dissipation required, I would prefer liquid cooling through cold plates

But if you finally do it, I'll I'll follow each and every step with a lot of interest

 

[Eastwood]

Because for the bike to handle correctly and the suspension work freely it needs the sprocket at the right place close to the swingarm. The only way to do this is wih gear reduction.

Any updates? Curious to see what you got in the works!

 

[rivvs]

I made some progress. This build will take time since I did not buy a roller frame instead Im buying parts to make the bike. The motor mounts are done

The final desing of the chaincase is done. 3d printed to see fitment.



What took a lot of time was fitting the alta front forks and the rear shock.
machined a new steering stem and rear shock mount.

now it start to look like a motorcyle.

 

[TysonScott]

wow look great!

whyd you go with alta suspension?

 

[speedy1984]

Best build on the forum :wink: