Le Toy II electric street bike

Discussion in 'Electric Bicycles' started by johnrobholmes, Aug 4, 2009.

  1. johnrobholmes

    johnrobholmes Member

    I have been working with electric bikes for about two years now, and have a new favorite build (aren't they all favorites?). The dirty component list:

    24 Bikes "Le Toy II" street/trials frame
    2003 Marzocchi Z1 Dirt Jumper fork
    Profile cranks
    Thompson stem
    Hayes Stroker 8" front brake
    XTR rear V brakes
    9 Continent hub motor
    12s 10ah Zippy lipo
    Castle HV110 with 800uf added capacitance
    Servo tester
    Magura 5k POT throttle
    Handbuilt front wheel Marzocchi hub/Salsa Delgado rim/DT spokes


    Here she is in "stock" form
     

    Attached Files:


  2. johnrobholmes

    johnrobholmes Member

    She goes about 27mph on the flats and gets to top speed in a hurry. Range is around 15 miles with zero pedaling, about 12 if I ride hard and stand up a lot. It is quite the fun ride, but a bit hard to bunnyhop compared to a normal bike.
     
  3. bluegoatwoods

    bluegoatwoods Well-Known Member

    It's a fine looking bike and 15 miles with no pedaling is very reasonable range.
     
  4. johnrobholmes

    johnrobholmes Member

    Thank you sir :euro:


    I think I am going to add some umph to the build. The frame and fork is stout as all getout so I am beefing up the wheels and changing the power plant.

    I laced a 17" motorcycle rim into a Marzocchi 20mm front hub with 10ga stainless motorcycle spokes. Tire is a Shinko 17x2.5 DOT rated dual sport. After riding it and loving the stability, I think I may do the same for the rear and convert this to a divorced drivetrain. I also have some slick DOT rated tires that are 2 lbs lighter than the shinkos (also DOT rated). This particular wheel is earmarked for another build, but I figure I can test it out on this guy for a while. :whistling:

    Who am I kidding, it is here to stay. I already ordered a fatty single speed hub for the rear to lace up to match. Now do I get a 16" or 17" rim for the back :scooter:
     

    Attached Files:

  5. AussieJester

    AussieJester Member

    Nice build nick looks familiar :p

    KiM
     
  6. johnrobholmes

    johnrobholmes Member

    I have been putting a good many miles on this bike, using about 700 to 800 watt/hours per day on my commuting days. Then I like to joyride and go to friends houses on top of this :grin5:

    I laced up a PUMA motor into a Rhyno Lite rim, and have been running it for a few weeks now. It runs very solid on 12s lipo with the HV110 controller, but with an old firmware it lost sync because of the high motor inductance. A firmware upgrade fixed the issue, Castle was already aware of it.

    I decided to use a Shenzen Sucteam controller and put 72v on the motor. It climbed like a goat and ran very stout for a few days. Then I hit a pothole on power going over 30mph downhill. It broke all three gears as the wheel unloaded and reloaded on the backside of the hole. Not a good hubmotor for 72v.


    So the 9c wheel is back on the bike, but relaced into a black Rhyno like rim with better spokes. It is pokey at first compared to the PUMA, since it has a higher resistance and inertia. But, the middle range power is very nice as a PM motor should be. Top speed seems to be the same as the PUMA, but hill climbing slower if I start the hill slow. I MAY relace the hub again with a drive side outbound radial lace. This will bring the dish better and lower drive side tension, making the wheel balanced and laterally stable.



    I am going to weld up a rack for the batteries and weld some tabs to the frame so that a divorced driveline can mount. On future frame builds I will weld bearing cups so that jackshafts will be integrated in the frame. There will be adjustment mechanisms or tensioners involved. That is the next build however...
     
  7. johnrobholmes

    johnrobholmes Member

    I remounted my batteries and controller onto a rear rack to clean up the frame and play around.


    The added rear weight bias makes it handle horribly.
    The rear skips over bumps and is unpredictable in rough cornering.
    The front unweights and skips when turning
    It also takes longer to lean from one direction to another. (seems odd since the center of mass should be similar to old position, maybe even more centralized)
    It is harder to park at racks, since it is topheavy.
    With the reduced front weight it wheelies a bit too easy now.


    I will be making a rack to hold the batteries around the top tube, very similar to a motorcycle gas tank. This thing handles like a bag of runny **** now. I can't jump down stairs like this either. I figured this would happen, but I didn't think it would handle so badly with the weight change.

    crappy phone pic
     

    Attached Files:

  8. AussieJester

    AussieJester Member

    I think moving the batteries towards the middle is going to help but not solve the handling problems, I freakin LOVE that front rim you have laced in good luck bending that out of shape haha...one lined up for the rear also or is it not possible with the hub motor?
    Im not familar with this 'DOT' rating business we have no such thing here in OZ...is the tire (on the front) thats DOT rated meant for bicycle or light motorcycle use? I would very much like to follow suit with the rim/tire/spoke combo on my new buid did you buy this rim online or from LBS? it just looks badass tuff unbreakable and having had a massive off from front tire failure before im somewhat paranoid about front wheels now :-S

    Hope the re-organisation of weight gets you the handling your after anywayz John...

    KiM
     
  9. johnrobholmes

    johnrobholmes Member

    When I had the batteries tucked in the frame it handled great. I will be remounting them like they were.


    DOT is department of transportation. Vehicles need DOT spec tires, or they are not street legal. Ebikes have no such restriction, but mopeds and scooters do. I got them because they were beefy and would not shred up like bike tires do. Just a few hundred miles on my rear bike tire and it is showing wear. I should get thousands out of the DOT tire. It is a dual sport tire designed for a bike that weighs 300 or 400lbs. It may not have the grip that a bike tire has, but I can deal with a bit slower cornering speed.


    I won't be lacing up a hubmotor into one of those rims, just because I would lose too much speed. I have a single speed 135mm OLD rear hub that is delegated for the task, but I will have to use a divorced driveline. Not sure if I will do that to this bike, or save it for another bike.

    I got the rim from OEMcycle. I had to call up and get the rim, since the webstore selects rims based on model instead of rim spec. Only available in 28 and 32 hole versions, but 32 hole mtb hubs are easy enough to find. I got the spokes custom cut, don't remember the place.
     
  10. AussieJester

    AussieJester Member

    Appologies i scrolled up and checked previous pics of battery placement, when you said "very similar to a motorcycle gas tank" i assumed ontop of the top bar, lowering the weight down will definitely be a big improvement ;-)

    Cheers for the info on the tires/rims...i shall checkout the site you mention and also hit up some moped/scooter sites also...They definitely look the part MUST have hehee...OH..spokes...you would of had to drill out the stock bicycle hub holes to suit larger gauge spokes? This doesn't make the hub too much 'weaker' does it? like, there is still adequate "meat" on the hub so the spokes wont 'pul' out and break the hub?


    Thanks again mate ;-)

    KiM
     
  11. safe

    safe Active Member

    If you go back to Endless Sphere I had posted a lot on a very involved thread about how center of mass effects handling. The mistake most people make is thinking that the axis of rotation is a constant at all speeds, but in fact the axis angle changes. The faster you go the more rotation occurs along the horizontal axis, while the slower you go the rotation occurs on an axis that goes from about the top of the front wheel (typically) to the contact patch of the rear wheel.

    Anyway... we all kind of know intuitively that rear rack mounted battery ebikes are going to handle badly... but just how badly it really is can come as a shock. (no doubt)

    You probably remember it:

    http://endless-sphere.com/forums/viewtopic.php?f=3&t=5891&start=465&hilit=center+of+mass

    [​IMG]
     
    Last edited: Sep 7, 2009
  12. johnrobholmes

    johnrobholmes Member

    I chose my hubs specifically for drilling out. High flange downhill or street type hubs. The front is a marzocchi qr20 type. The rear I don't recall offhand, it is a cheaper one.

    I did have to size up the holes a few, from 14ga to 10ga.

    I certainly do remember that long *** thread, and the handling changes significantly with speed. At higher speeds I didn't notice much difference, but at lower speeds I could feel the weight jacking the rear around. I typically use front brake only, unless entering a turn. Every time I hit the brakes I could perceive that weight behind my *** acting up.

    For slow putting around the low slung weight would be great, for really fast corning higher weight would probably be best. For the way I ride my bike I need the weight centralized in the bike, otherwise I can't yank the bike around fast. I want to at least hop curbs at speed again.
     
  13. safe

    safe Active Member

    As I recall the "saddlebag" location works pretty well for touring. Just getting the weight lower in the rear will help. However, a lot of the tricks that you do on a mountain bike require the balance to be just about perfectly in the middle.

    There was a guy using the name "Tiberius" at Endless Sphere that mounted his batteries really high and forward and then entered a race in England and blew away the competition. He said he was really pleased with the way it handles at higher speed even though at slow speed it tended to fall over.

    Higher weight locations will tend to rotate more easily in the front, but it will rotate less easily in the back. It really all comes back to those orthographic vector diagrams I had posted. In order to rotate a mass you need leverage from traction, but if the center of mass is offline of the natural rotation axis then the mass has to rotate itself in a semi circle which is the root of all the weird feeling behavior. It's a complicated topic that's for sure...
     
  14. johnrobholmes

    johnrobholmes Member

    I am putting this particular build on hold for a while. I sold off the hub to a friend so he could get his ebike up and running. It will allow me to focus on other builds in the mean time, and put a fire to get them done. In the mean time I am riding around a 50cc gasser that gets 90mph. Sad but true, the gasser is less expensive to operate over the long term since I use Lipo batteries on my builds, and the initial cost of vehicle was rather low at $600 built.
     
  15. safe

    safe Active Member

    LiPo and LiFePO4 are great performers, but expensive.

    You might think about doing something like I did with NiCads and solderless tubes. The NiCads last a long time, are idiot proof, and the solderless tubes allow you to easily repair cells that go bad. (which they always do) The SubC size allows for 10C discharge rates, so that's an added plus, but I tend to use more like 3C at most.

    Gasoline is better on the "bottom line" than electric.

    It will take at least $4 gasoline before that changes...
     
  16. AussieJester

    AussieJester Member

    ahhh..safe...He sells batteries pal i think he is well aware of the price of things

    http://holmeshobbies.com/home.php

    He owns an online store OH OH...reminds me i need to order the programming
    gear for the HV110 ESC from you, shall put through an order next pay mate :)

    KiM
     
  17. safe

    safe Active Member

    I forgot...

    Geez... when a guy that sells batteries decides to switch to gasoline then you know that the economic argument for "Going Green" is in the toilet. ("Going Obama?")

    The Lipo and LiFe batteries are great as far as performance, but they are still expensive compared to NiCads. However, even when it comes to the NiCads the "special deal" that used to exist at All Battery has gotten more expensive.

    What used to be:

    100 NiCd Sub C 2200mAh Batteries for PowerTools No Tabs - $109

    is now:

    100 NiCd Sub C 2200mAh Batteries for PowerTools No Tabs - $160

    ...the price is going up not down.
     
  18. AussieJester

    AussieJester Member


    Nothing we didn't already know though Safe ...has always been the case, Electric is a hard sell simply due to the cost before you even get to the
    complexities and range issues.. BUT...not everyone does it for the 'green' factor granted the majority do but there is a select few that
    get a kick out of the performance...i believe you refer to them as "outlaws" :p I would have a watercooled 10hp 47cc pocket bike motor in a bike in a heart beat if i knew i could get away with it here, i can't i would be nabbed soon as i left the hills.

    KiM
     
    Last edited: Oct 21, 2009
  19. safe

    safe Active Member

    Your reality "makes sense".

    Given your ability to get the "free pass" with the "mobility scooter" it allows you to go infinite on the power side... as long as it's electric. Try to switch to gasoline and you lose your "free pass".

    It still leaves the rest of us scratching our heads about the meaning of all this... I don't think that the expensive batteries are worth it for me, at least not now. Everyone keeps hoping that some breakthrough will occur where batteries suddenly become competitive with gasoline, but it just never happens.

    Sport seems the only angle worth bothering with... so my "EBRR" concept is (though heavily ridiculed) actually the "most realistic" avenue to look into. The Go Kart guys are now getting pretty good at electric, so maybe Go Karts and EBRR machines can all race on the same tracks.

    You saw this right?

    Imagine that motor on your next machine!!!

    http://www.greenmotorsport.com//products_and_services/3,1,388,17,12958.html

    ...they even say that the motor is for:

    "Personal mobility vehicles"

    ...so you could use it. (36 hp for only about 36 lbs)
     
    Last edited: Oct 21, 2009
  20. johnrobholmes

    johnrobholmes Member

    The tradeoff is right at $4 per gallon for a lipo to break even on cost vs gas. LiFe generally does better than gas because of the much longer cycle life, but it depends on which cells you pick.

    With the energy it takes to produce a battery, ship a battery, plus the charging energy, I can't say that I feel it is more "green" than an efficient guzzler. Would be an interesting study if you are into carbon footprints.



    I am already started on another project. Actually two of them. One is converting my santa cruz Bullit to electric, and the other is making a series-parallel hybrid with a 50cc engine.
     
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