Luna cycles Sur-Ron Electric trailbike

Discussion in 'Electric Motorcycles' started by dogsslober, Jan 2, 2018.

  1. liberpolly

    liberpolly Nu, shoyn, nudnick!

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    Actually this throttle weirdness may be the best way to manage the insane torque curve of an electric motor. Quite a few people high-sided their Zero motorcycles because their throttle hand wasn't trained to that. Traction control is another solution, but you cannot expect that in a $4K bike.

    Try giving yourself a chance to get used to it before modifying it...
  2. TeeJayIdaho

    TeeJayIdaho Adventurer

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    Maybe yours is screwy. I don't notice anything like what you are feeling on mine. I've had my X bike since last November and I haven't once thought the throttle was problematic - although perhaps all my other bikes are POS's / beaters in your view. Been on other forums where they discuss this bike in depth and the throttle just doesn't seem to come up much. Now if you want to complain about brake strength (or lack thereof) I'll happily agree on that. Winter project will be to swap in some better brakes that stop faster / stronger so I don't blow through corners.
  3. dentvet

    dentvet Long timer

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    Bring yours to the barton ride this weekend and we can compare bikes. Electric dirtbikes without a clutch are going to be a compromise but its interesting to hear that the EM bike was way better than yours.
  4. smdub

    smdub Adventurer

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    I have like a half dozen other bikes that all feel roughly similar (not absolute power wise but in linearity.) The SurRon is definitely the odd man out so it's the one that'll get tinkered with. If it made as much torque as a Zero than maybe that wouldn't be warranted. :)

    Barton ride? I'll be in New Windsor MD on Sunday for the MAVT trials event.

    The EM on its full power map MIGHT have had a hair more throttle lag than the SurRon but it was hard to tell without going back and forth a few times which I didn't do. It weighs slightly more too so that may be some of it. Maybe mine really is a one-off problem. I didn't get a chance to map the sensor tonight. Oh, stoppies/nose wheelies are another place it really shows. It takes a huge amount of twisting your wrist down to start moving forward again when all it should take is a little flick w/ the amount of torque it has.
    ToriMish and Bucho like this.
  5. ToriMish

    ToriMish Long timer

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    Well, I've been considering an E-Moto for quite a while now, and had been very interested in the ALTA (now bust), the KTM Freeride E (not available in Australia), and the Electric Motion EM Escape. Out of these the EM Escape is available here in Australia, but for a price of approximately $15,500 . . . I've done a bunch of reading about the Sur-Ron and have watched a bunch of recent videos. It looks like the bike to go for - the pricing is excellent for what you get and I think it would be an incredible play bike for my local area. I reckon I'll place the order this week. Can't wait.
    HapHazard likes this.
  6. ToriMish

    ToriMish Long timer

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    Hey NAM - I'm a few hours from Melbourne in the Grampians and I am trying to find a good supplier for one of these. I can't find any Melbourne/Vic suppliers - but I have happened across AE Bikes (https://www.aebikes.com.au/) - and they have good reviews and support. Where did you source your Sur-Ron?
  7. TeeJayIdaho

    TeeJayIdaho Adventurer

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    Nice area the Grampians! Did some hiking there a couple times years ago when I lived in Bendigo. Probably have some photos around somewhere of me on the balconies. :-)
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  8. Mikey Boy

    Mikey Boy Been here awhile

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    I'm considering one of these. I can register it as a moped in CA for street legality and hit the trails. Might run into problems on MTB trails though.

    It looks like a blast and in a class all by itself.
    voltsxamps likes this.
  9. smdub

    smdub Adventurer

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    Ok, the throttle sensor is indeed non-linear (see the graph below.) I stuffed my Fluke multimeter probes in the connector and started subdividing the wheel movement at the box. (Did this w/ the kickstand down so the bike wouldn't move.) My tick marks weren't perfect so the line is a little jumpy but you get the idea. Its clearly S-shaped. The gap from the magnet to the hall sensor will shift the whole curve up/down so some may be on a straighter part of the curve than others.
    Sur-Ron_LBX.jpg

    I put the bike up on a stand and adjusted the throttle 'slack' at the grip until it started spinning the rear wheel. That took 0.96V. I backed it off about 1.5 turns to 0.9V for 'off' throttle. That at least gets me on a straighter part of the curve. Riding it around its much improved but still not great. Was just testing in the back parking lot w/o any real hills. It's now difficult to hold the bike back w/ just my feet at half throttle (I put tick marks on the throttle grip too.) I might put a current clamp on one of the motor wires to test but it SEEMS the controller input may be fairly linear and the curve is mostly from the throttle 'pot'.
    woodsrider-boyd likes this.
  10. woodsrider-boyd

    woodsrider-boyd Wow, these guys are fast

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    I am completely ignorant of how our battery powered electric bikes work, so forgive me if this suggestion is ridiculous, but would a throttle from another e-bike like an Alta work better with the Sur Ron? The throttle response on my Alta is amazing, very predictable, very consistent, and very easy to precisely control, its one of the things that I love most about it.

    I'm guessing that the throttle response is partially controlled by software, and partially controlled by the physical design of the throttle?

    Just thought I would throw that out there in case you cannot get your throttle response setup the way you would like it. Alta parts are hard to come by now, but there is a company selling NOS parts on ebay if you decide to explore that option. They are just starting to inventory their Alta parts and I would guess they have the throttles, but you might have to ping them since they are not listing them on their ebay store currently.

    https://www.ebay.com/sch/m.html?_od...lta+throttle.TRS0&_nkw=Alta+throttle&_sacat=0

    Good luck with this issue, and keep us posted. -Eddie
  11. TeeJayIdaho

    TeeJayIdaho Adventurer

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    Definitely a blast to ride! But yes, if you try to take it on MTB trails you will undoubtedly have problems / complaints. We've got a pretty good network of MTB trails around me but I know that I wouldn't get 50 feet down those trails before the cops were called. So I just treat it like my gas bikes and take it only on trails and roads that I'd take those on.
    WetSideRider likes this.
  12. TeeJayIdaho

    TeeJayIdaho Adventurer

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  13. motodojo

    motodojo Been here awhile

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    Supposedly, a new law is now allowing ebikes on mtb trails on federal lands. With a pedal kit the light bee will be an ebike.
    https://www.pinkbike.com/news/us-se...or-opens-national-park-trails-to-e-bikes.html
  14. SteveAZ

    SteveAZ Long timer

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    I'm pretty sure the regs regarding e-bikes on fed land will be limited to class 1 & 2 and sur-ron, even with pedals, isn't even close to a class 3 although they do sometimes try and pass it off that way
  15. smdub

    smdub Adventurer

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    Yes. Theoretically I could replace the throttle box w/ another. It is powered by 5V (well, a little less) and needs to output 0.8-3.6V over the desired range of motion. I could adapt one of the literally dozens off other ebikes/scooters and likely even the Alta. That is one option I have. Though I'd likely have to test many to find one that works best (I might prefer a non-linear curve that is more aggressive at the start. Won't know until I try.) It would be trial and error finding one.

    Anther option is throttle cams. I could ramp a cam on either the throttle tube or the throttle box (or both.) I could calculate the profiles and CNC machine some.

    The last option (and the one I'm currently favoring) is an electronic approach. I can use a small microprocessor inline to read the throttle signal via ADC (Analog to Digital Converter), run though a curve function, and output that via a DAC (Digital to Analog Converter) to the X controller. I could then quickly try many different curves/profiles. I'm an EE and probably have an appropriate eval board sitting around here I could splice in. It's likely the fastest way for me to test multiple curves. It doesn't have to be the final solution either. I could always choose to later machine a throttle box cam that replicates the electronic curve I ended up liking the best. Though electronic would have some other advantages. One could support two different curves based on eco or sport mode for example.

    It would be convenient if I could identify the connectors that Sur-Ron used. It would allow me to build an inline test harness and not cut the throttle pot wires. I haven't searched for them yet.
    Bucho and woodsrider-boyd like this.
  16. woodsrider-boyd

    woodsrider-boyd Wow, these guys are fast

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    Right on. Good luck and keep us posted, sounds like an interesting little project for the bike.
  17. dentvet

    dentvet Long timer

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    I tried to duplicate the issue you describe of nose wheelie to regular wheelie and there is a lag in response. That said, general offroad riding felt pretty normal (as far as the throttle response goes) to me this weekend.

    I think the throttle mapping is done for safety or rideability for the masses.

    I just ordered one of these throttles just for comparison sake: https://www.ebay.com/itm/Sur-Ron-Su...997825?hash=item23c458a001:g:xoYAAOSwZ75dYvqk

    I'll continue to modify as the bike is too cramped and low on power in some extreme climbing scenarios.
  18. SteveAZ

    SteveAZ Long timer

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    My experience is that the chinese don't overthink this stuff.... or frankly.... mostly don't think about it at all and they just get what they get when they throw it all together unless something is just super wrong

    Not to say I wouldn't buy one... it's one reason I follow the thread... but I know dealing with this chinese stuff what we're getting into... working with luna ain't perfect but a hell of a lot better than just doing an alibaba purchase...
  19. CableDog

    CableDog Adventurer

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    I bought one 2 weeks ago. Best 4k I've ever spent. It's not a motorcycle it's not a bicycle. It's better. I can pull out of my front door with no mess and the world in my play ground. Silent as a ninja on a work night or Sunday morning before church traffic, a wisk in the wind, a side walk to curb assassin. Quick turning with killer suspension. It does need tweaking out of the box, replacement parts are a pia but overall I give it a 9 out of 10. This thing is fun AF!!!
  20. troy safari carpente

    troy safari carpente Team f5oolery

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    As far as real world "dirt bike/off road" capability goes (as benchmarked by contemporary enduro/motocross type bike standards) this appears to have put its sights on the bar - or thereabouts - set by the ALTA Redshift or TACITA t-racE moto's.

    I'm all ears... :ear