New Project: KX-E Supermoto

here's whats happening

i picked up this 2004 kxf250 roller for a pretty awesome price thanks to the guys down at Eastern Motorcycle Wreckers (Victoria, AUS)


the plan is to drop it on 17in motard tyres and combine it with 2 GNG big block motors i picked up from mrtao a while back. all going well i believe this will be a nice power plant for an inner city commuter.
here's a few pictures of my current mounting solution:

front mounting plate:


rear mounting plate:


wooden cutouts mounted in the bike:
View attachment 2

close up:



im aiming for a geared top speed of 85km/h running on 24's (88v) LiPo cells and a distance of around 30km on fairly flat Melbourne roads (enough for a return trip to uni.)
based on the Big block kv of 62 this will be achieved with a 6.8:1 reduction ratio.
as for chain selection the #219 pitch looks suitable and makes this ratio quite achievable with a single stage reduction. the issue i face at the moment is finding 16mm straight bore keyed 219 sprockets as all seem to be either tapered shaft Yamaha style or 3/4in which are too large for the motor shaft. if there is a suitable off the shelf solution id love to hear about it

there's still plenty of detail to fill in here regarding ESC selection, battery capacity and BMS which i hope to gain from this awesome community of e bikers

further details to come:

Is that licensed, road legal?

Or you gonna put pedals on it

haha unfortunate i don't think pedals are going to fool anyone..
Actually I'd love to eventually get it all compliant and road registered, of course that's a long way off. The plan is to first build, test/fix bugs, then once everything's running smoothly approach an engineer to see whats needed for compliance. from what i've read its far easier to start with a motorcycle such as the kx'er and get the modifications approved than to build from scratch, maybe someone who has been through this process can add their opinion.

or maybe i will add pedals for show and have a 200w limit switch for when the po po roll past :wink:

If it doesn't currently have an ADR compliance plate then no chance. Unless you pay multiple $1000's of dollars.

hmm yep bummer. well i guess she'll have to be a fun machine only.. maybe one day ill transfer the components to a compliant frame and follow that dream.
ill ponder on that idea of pedals i cant see it being a major issue as there's a portion of motor shaft protruding on the opposite side that could be utilized for pedal assist lol

I agree about the compliance plate thing- this will never be passed for the road unless you go through the individually constructed vehicle route- which is a pita.

As for motors I know you're fairly set on the gng's but personally I'd go for a John in CR mini hubmonster (single controller) or hubmonster (two controllers) and run them as a mid drive.

Whichever way, keep the updates going and good luck!

What kind of combined power output are you looking to get out of those motors? I am looking into a similar type of dirtbike, but not gonna put pedals on it. I have a 2002 CR80 bike that I am debating the merits of selling the motor and throwing a hubmonster in.

i have had similar thoughts, although the conclusion i've come to is to go ahead with using these motors with the idea that the mid monster will be compatible with the controllers i buy, so down the track i can swap if need be.

i would like to see 16kw peak combined with these motors, i don't think that's too far fetched with good heatskinking with the alloy mounts.

as for progress, uni has got me pretty strapped for time. mid semester breaks coming up soon though so i should have the motors mounted and the chain drive sorted by the end of the month. still not sure which chain to go with to link the motors to each other and to the rear wheel. id like to use 218 chain but the 5/8in bore on these motors makes that impossible with off the shelf products

5/8 is close enough to 16mm to hand ream. What diameter drive sprockets are you seeing?

Another way of doing this would be to get a 5/8" drill bit and mount the sprocket over the drill bit (it should fit on snug) in a drill press. THEN you clamp the sprocket down (in a vice or clamps) so now you have the sprocket in line with the center of the drill press spindle and can now drill and ream to whatever size is available. You will have to absorb the price of the drill bits and reamer, but now you will have the ability to make any sprocket fit your motors.

unfortunately the motor shaft is 5/8 and the sprocket is 16mm, so unless there is a #218 sprocket that is 5/8 diam or less reaming isnt an option

Well, in that case all you need is a beer can! Just use it as a shim and wrap your shaft to get the proper fit. Many here have used this method with success. Another option would be to get some shim stock in .0025" and wrap the shaft, or you could gut the proper size from a feeler gauge set and wrap the shaft. Either way, don't forget to WRAP IT UP!

Hey Mitch,
I am still thinking big block and noticed these guys over the road from me the other day:
http://www.ebay.com.au/itm/Bore-Key-Machining-Pulley-or-Sprocket-from-our-eStore-grub-screw-included-/111365626049?pt=AU_Building_Materials&var=&hash=item19ede898c1

Otherwise there might be a 16mm off the shelf...
http://www.smallparts.com.au/store/categories/Sprockets+PosiDrive/

SD