jonescg's NEW electric racebike BUILD thread!

Thanks,
I was just reading up about that. "chain pull angle".
I imagine regen-braking would be one of the big reasons to aligned with the swing-arm-pivot. But other than that, it seems you are right about it not being a big-enough issue to see done on many motorcycles.


Mike Edwards said:
EBJ said:
How is it that a motorcycle can get away with having the pivot-point of the swing arm at a slightly different location than the drive-sprocket? Is the whole point of chain-slack to allow for that? Seems to me that having a jack-shaft at the same pivot-point of the swing-arm would be a better option, but I don't think I've ever seen that on a motorcycle.

Why not?
Do you think it is just adding too-much complication to have a second drive-chain, or... does having the drive-sprocket at a different location than the swing-arm-pivot actually provide some sort of benefit?
Click to expand...

Having the swing arm pivot in a different position to the chain drive has advantages and disadvantages. If you read up on squat and anti-squat with regards to the suspension you will get an idea of what I am referring to. Ultimately the pull of the chain operates at a different angle to the movement of the swing arm/suspension so it can have a positive affect but generally it is considered negative.

The only electric bikes I've seen that have had the motor drive on the same axis as the swing arm pivot are Kingston University and The Danish Future Electric guys (http://www.futureelectric.dk). In theory it is the most desirable solution but it relies an awful lot on the flexibility and stiffness of the rest of the chassis. In my opinion nobody has managed to get the balance of the two right so far.
Click to expand...
 
EBJ said:
Thanks,
I was just reading up about that. "chain pull angle".
I imagine regen-braking would be one of the big reasons to aligned with the swing-arm-pivot. But other than that, it seems you are right about it not being a big-enough issue to see done on many motorcycles.
Click to expand...

I suspect I am the only person yet to be convinced about the benefits of regen braking on an electric race bike.

On track many people trail brake to the apex of the corner. The complexity of being able to balance the real braking with the regen as the bike leans over without overloading the front are just mind boggling.

Sure there may be a place for it when the bike is bolt upright but at the limit the balance of the bike is too important unless you can have a perfectly smooth transition between the two.
 
Yeah, there's no real point for regen on a race bike for two main reasons. Mainly: Your rear wheel braking is non-existent since if you are hard on the front brakes, the rear wheel will be skipping along the asphalt. Secondly; we are pushing our motors to the limits, so they are hot. The regular racing cycle will be like 90% WOT and 10% off. Regen would make that 99% on and 1% off. So you'd be heating up your motor and not giving it a chance to cool down on the off-duty part of the racetrack cycle.

It's nice to have a little bit of 'engine braking' when you throttle off, but for the most part, it will be switched off.

Ratking; I will endeavour to get as many pics as possible :)
 
Farfle said:
Is that swingarm assymetrical?
Click to expand...

I believe it is because the wheel doesn't sit central between swingarm sides. It's off center to give room on one side for the sprocket and then to allow the chain to fit through the swingarm too.
 
Not only that, Ducati had a pair of exhaust pipes going past it, and the shock mount was off to one side to accommodate it. Now it will have a 5 x 50 mm2 cables going past it :D
 
The reason I use regen on my bike is mainly for the weight saving of not having a lever/pedal, disc and caliper (3kg).
regen is used both in straight line braking while the front is full on and is left on through the transition into tip in as I let go of the front brake and right up to apex to keep scrubbing speed off then get straight back on the amps no gap to neutral throttle and then roll on.
Regen is good because the more volts you have left at the end of the race the better chance you have of out gunning some one to the flag.
Every iota counts. Plus regen is a very user friendly feeling brake as long as you have pot modulation.
If you have a overheating problem, regen isnt the cause, its not having a big enough cooling system.
 
G'day Dan, congratulations on moving on from lurker status :D

I'm still a good $15k shy of where I need to be for this bike to be on the track at any point. All things going to plan I will have it ready to roll EXCEPT the controller and battery packs in about late April.

Interesting about regen. I figure if I allow the motor to cool more during deceleration, I can hammer it harder under acceleration. If I was employing regen at a significant level, all things being equal I would be no better or worse off, except that the complexity of the system is lower. I'll only have 9 kWh on board - 30% more than last time but at considerably more power.
 
Quick question Chris and hope its not off topic

Would randy able able to build a frame based on the same motor that you are using that can be exchanged for a registed road bike. Would it be legal.
 
I can't see why not. Regardless of the motor that's in there, the bike needs to pass ADR, and most of that stuff is cosmetic. Approved turn signals, headlights, numberplate must be visible to revenue raising cameras etc. The department of transport will have the final say, and they will normally get their advice from an engineer who they get to choose.
 
Hmm you know what
my pack would fit right in that frame. 250 wide, 185 deep and 735 tall.
And Ive just ordered another $6k worth of Lipo cells from YGS
so I will have 2 packs but they will be 177v.
I am tempted to go higher voltage (350v) but not 700v
That would mean $9k on a Rinehart straight away.
Ive just asked Yasa for a quote on a 400 but of course thay havnt responded.
Looks like they are already corporate and not dealing with Prototypers

MCD_1632w1_600_clear.png
 
Yes, Yasa offered me a motor for 7000 pounds, and that was the best they could offer. I declined, and went for the more affordable 5000 pound motor. Now neither company will sell one-offs.

Two packs eh? Good thinking - it means more time lapping and less time charging. Although all of the high voltage isolation is built into my pack, so a second battery wouldn't be cheap.

I kind of wanted the frame to be future-proof, so when the next best chemistry in a convenient format comes along I can rip the cells out and put new ones in.
 
The frame looks good!

On the high-voltage topic - spoke to the 600V e-bus driver on the weekend. Their 1st prototype didn't have any BMS/monitoring :shock:
Check out the size of that motor. Not an option for an e-moto obviously..
file.php

file.php
 
Thanks Dmitrii, I have a few more PCBs for you to draw up for me if you need some cash. My new workplace is VERY keen on some EIG cells, so there could be a big purchase of them sooner than first thought. I've been working on a better PCB layout for them which should fit snugly.

In racebike news, my battery box has been submitted for construction! All of the sheets of polycarbonate are being CNC cur and drilled, so hopefully everything will line up as planned.

I have also received my two 6 amp chargers. At 350 V each :D I need to come up with a control box which both monitors their current and voltage, as well as having an output divider for the ENABLE lead. This means I can drip the charge current down to 3 amps if I want to bring it up slowly for balancing / monitoring, or if the power at the racetracks are woefully inadequate.

I am wondering if I'll even need a HVC because the cells are only ever being charged to 4.167 V per cell...
 
Another update from Randy:
framework020_zps35cfb264.jpg


How stiff is my frame? :D He's at a point where he can work the suspension and the motor mount into the frame. Now, a simple monoshock would give you about 87 mm of linear wheel travel with limited adjustability. So he has proposed building a linkage system into it so I can potentially squeeze about 100 mm of travel and another 15 mm of shock adjustment. The rising rate can be changed too. So, this adds cost and complexity, but makes the bike considerably more accommodating to tune-ups.

Another point is the motor mount. He's got the option of mounting the motor with room for adjustment about the swing-arm pivot. This means the anti-squat can be adjusted. The bike appears to squat under acceleration. It's called anti-squat because technically the bike actually pops up a bit. It looks like it squats because the weight of the rider is left behind, causing it to drop at the rear. Critical at the point of throttling on at the apex, you want the bike to still have some travel, rather than bottom out right when you need the traction most. At least that's my weak understanding of it :lol:

So I have opted for the added adjustability, so the talented rider who isn't me can tune it to get the best out of it.

Jay - what do you reckon? Sounds right?
 
Definitely go for having a linkage if you can. Even better if you can bolt on different offset mounting points on to the swing arm for greater adjustability later on.
 
I have also agreed on perhaps the most important part - the colour scheme :D

Keeping it West Australian parochial and gets back to my plant biology roots. Can you see the motorcycle front end in this, our state's floral emblem?

a-mangl.jpg


Red trellis frame and green nosecone, tank etc. Should look good :)
 
Jonescg ..have you seen these ..
http://elithion.com/battery_blocks.php
and info on how they are assembled.
http://liionbms.com/cgi-bin/moin.py/CustomProducts/EDI/EnerdelBattery#head-5c4b017c9f3c02caf73aac63cb87f518f09bd642-6
 
That's really neat. Interesting that they needed to put heatsinks between each cell. I'm always a bit cautions of placing any metal between cells long term, but if they get hot it's good to know you can cool them. Not sure how they'd fit on my bike though...
 
Brace yourselves for an update!

I picked up my flat-packed battery box from BCJ Plastics in Osborne Park. The precision drilling, tapping and routing was well done, but they somehow forgot to make the two dividers. They've since been done, but I have to pick them up on Monday. I also noticed the bevelled edges were cut wrong. They have apologised profusely, and after I gave them the option of either making me two whole new panels or making two little triangles I can glue in place, opted for the small triangle option.

Now the beauty of the clear polycarb box!

The batteries stack below, the contactors and fuses are directly above, and on top of that is the centralised BMS. The main control box will mount to the outside rear of the battery and this is where the relay logic board, main contactor, current sensors, precharge / discharge etc sits. It's currently suspended by my wife's PhD thesis.
BatPack003_zps102444d9.jpg


I haven't got the side and top covers made yet as I was first keen to see how it all lines up. I suspect some kind of active cooling might be good, but I'm not sure how. Keeping it waterproof is my main priority.
BatPack002_zpsbe16f60a.jpg


I loaned my three Gigavac contactors to Entecho as we build the electrics for the hoverpod, so I hope to get my replacements soon. One will go inside the main control box, one for the RHS with 200 A fuse and one to replace the half pack contactor (the one pictured doesn't have auxiliary contacts to warning you if the thing is welded shut).
BatPack004_zps81ec1c81.jpg


I now need to route the 50 mm2 cable out of the box and into the control box, and also try to route the charge cables out too. I'm inclined to take them out the front of the box because there's room for it, but I don't know how it sits with respect to the chassis. The little 15 A, 350 V fuses are for the charge leads. As it's a split pack charge design I need one for each half-pack.

The dimensions are exactly right for a 42s3p LiPo pack to slide straight into each quarter. I need to get the final terminations right so they can connect to the switch gear on top. Braided line might be the way to go here.

The 10 mm deep recesses are so that the 45-odd battery fly wires can go past all the HV switchgear and straight up to a DB50 plug where they will plug into a fully custom BMS from EV-Power. It will end up costing as much as buying one, but at least I know it can fit. All it will do it monitor and warn, no balancing. The balancing is done off-board periodically using another EV-Power creation, mostly using those little balance boards I showed earlier.

So it's coming together!

EDIT to add - I will be glueing the floor to the front and back walls, as well as the bottom of the central dividers for added strength. The false floor with all of the switch gear will remain removable, as will the BMS shelf. If I need to remove a contactor or adjust some packaging I can do it, but I will try to limit the mount of time spent dicking around with at least 175 V on tap.
 
You must log in or register to reply here.

Similar threads

craciunptr
    • Like
    • Cheers
Launching the Kit Version of the Ride Colibri M22 E-Motorcycle
Replies
14
Views
970
craciunptr
craciunptr
C
Need advice on a honda c70 passport build
Replies
5
Views
1,938
100percentjake
1
J
    • Like
ATV Adly QS138 90H V3 + Votol EM200/2
Replies
6
Views
708
SlowCo
SlowCo
O
Battery Build Planning
Replies
1
Views
665
Hummina Shadeeba
H
jonescg
DIY Quadricycle ideas - 100 V controllers?
Replies
4
Views
1,596
AdR
A
Back
Top