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Track bike with 14" wheels

Discussion in 'Racing, Motorsports, and Track Days' at netrider.net.au started by Bluefang12, Jul 27, 2011.

  1. Hey guys and girls, I have been lurking in the forum reading random posts and learning abit.

    I am a Electric propulsion nut, i have had a few E-bikes that i have built one which went up to >70km/h and i have recently finished building a 50cc to electric scooter conversion driving through the CVT transmission which i am now just waiting for government red tape to allow me onto the road with it.


    I would like to build a high speed race bike to test afew theory's , i personally think for a performance electric vehicle a CVT transmission is godly, keeps the motor in high rpm which is fantastic for the motor and controller while multiplying the torque for low speed take off while still allowing a high top speed. The most appropriate bike i have found with a CVT that is easily adaptable to electric power is a Gilera DNA. The DNA has only 14" wheels and seeing as i want to build something that is capable of holding its own in the Electric motorbike racing i would like to know what your thoughts are on a 100kg bike with 40kw running thru a CVT hurtling down a race track at ~200km/h?

    Am i(or whoever rides it) going to crash and burn or is it possible with some tweaks, good tyres and some skill?


     

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  2. Not on this site, and a very long read, but you may find this, and this interesting.

    There was also a note I saw some-place that somebody at the recent US Grand Prix at La Guna Seca lapped an electric bike 10 sec off the pace of a motoGP bike, right in the middle of the competitive race lap times for a 600 STK. That's not hanging around.
     
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  3. To be close to a 600 bike is pretty good for electric, most of the bikes i seem to hear about have lap times similar to 400cc race bikes.

    Thanks for the links, i ll join that forum and have a read. :)
     
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  4. Don't tell them I sent you - they'll laugh at you. LOL.
     
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  5. <-- Is thinking of converting a mixed up Scooter/Motorbike to electric with only 14" wheels, I am sure they would laugh at me for other reasons :)

    Mentioned it to a guy at work to does track days etc, he couldnt stop laughing when i showed him the bike, "your going to go racing on that under powered scooter?".... Uhh it will have 40kw and weigh bugger all
     
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  6. Look - I'm not laughing. The Doc uses 2 Agnii motors [sp?] and he points out a clip on you2b where somebody put one - a smaller model - in a mountain bike, direct drive to the back wheel. So this guy get's on it, like, this is a big joke. Hey - everyone, look how slow this POS electric bike goes - and he nails it. It was like dumping the clutch on an R1 at valve-bounce! This thing flipped him SO HARD! It was friggen awesome!
     
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  7. #7 Bluefang12, Jul 27, 2011
    Last edited by a moderator: Jul 13, 2015
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  8. Haven't opened the links KD posted but in case you hadn't heard of it, try this site
     
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  9. Cool idea, a 40kw 100kgs sounds good, whats that 125 2 stroke specs, no well close.

    Wouldn't the issue be getting tyres that fit that are rated for that speed? The originals I would say weren't really designed for racing.
     
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  10. Yeah i guess getting tyres would be hard, but i am hoping that i can get tyres from racing scooters assuming they use 14" wheels, otherwise i might have to rethink the idea which would be a pitty as the DNA seems to be a very good base for a electric bike.
     
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  11. The thing is likely to be far more sensitive to track imperfections even if you can get traction from such small diameter tyres. Just something more to think about. And that engine looks like un-sprung mass, that will make it tricky to get the suspension working as well.
     
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  12. Ohh well i may have to go back to my other idea of using a standard bike and doing a custom built CVT on it. I just really liked the idea of having the CVT built into the swing arm and everything setup with out me having to get all sorts of approvals for modifications to the bike on top of the electric conversion.
     
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  13. Are you building a track bike only or do you want it registered?
     
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  14. I would prefer it to be both, but thinking about it i would probably build it as a track only bike. For personal transport i prefer my e-bike over short distances as its much faster thru traffic and more fun even with out a high top speed(Top speed limit to work etc is 60km/h).
     
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  15. why couldnt you swap the wheels for maybe some 16"
    I have toyed with the idea of making a electrice race bike the thing that put me off was the price of lithium batteries.
    Though i still want to build one hopefully before next year and compete in the ttgpx.
     
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  16. I have worked out that for a lithium battery pack using high quality Lipo from RC planes etc it would cost about $3k for a 7kwh pack. A BMS and charging system would be about $1k. The motors would be about $700+300 in extra parts and my time to rewind and improve them. The controllers would be ~$1k including shipping. About $1k for wiring, relays, contactors etc. The CVT if i am lucky and can get a swing arm from a trashed 250+cc scooter will be $1k once its been modified with belt, torque spring and rollers. Bike as a rolling chassis should be under $3k and then probably about $1k on machining to get everything to work together. So will probably work out to $12k and blow out to about $15k for a bike that i reckon has 40kw normaly and the potential for 60kw of power and a CVT drive so no gear changes slowing you down. Ambitious hey :)

    The problem with changing the wheels on the Gilera DNA is the CVT is part of the swing arm and is only large enough for 14"wheels :( But like someone else pointed out its probably not a good idea to use that bike seeing as the engine is part of the swing arm so its alot of weight where it shouldnt be.
     
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