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Luna Fixed Stealth Bike

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    Luna Fixed Stealth Bike

    * Work in Progress*

    Belt Removal:

    But first you need to remove that shifter box (aka click box), put it on 2nd gear and loosen the rear nut at the back of the shifter box

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    You may need to loosen up the tensioner just a little, it possible that yours is already at the maximum forward position in that case just loosen up the axles nut.

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    Now that the axle is loose and at the most forward position, please watch this video to remove the belt.

    CS note: We have been in contact with Gates and removing the CDX Belt like this is fine.

    Adjusting the belt tension:

    Gates carbon drives has an app (android and IOS) to tune the belt to the right tension (on this bike best is 45-60hz). Just need a quiet place to do the tension test and need to test at multiple spots.

    Just watch these 2 videos:

    If you need to adjust the shifting after re-installing everything , please watch this video:

    Adding fenders:

    (with thanks to reddit user /u/bourbonben)

    Planet Bike Full bike fenders - 700c x 45mm

    Had to trim the front arms, and cut the mounting tab off the back. I used a zip tie for now, will secure it direct to the brake bridge when I eventually have the back wheel off.

    Considerations for adding second battery for more range

    Generally speaking this is not advisable. It would require extensive modifications and could compromise the battery. Please note that Luna can not take responsibility for the consequences if you break your bike or battery. There are a few separate proposals, we will discuss each below.

    Manually switching batteries: Physically unplugging battery 1 from the controller, then plugging battery 2 into the controller. This would be the most straightforward, and eliminates a lot of potential danger in doing the other methods incorrectly. As long as the second battery is a normal 36v nominal battery that should be fine.

    Alternately, this might work to switch it (currently unconfirmed) If you do use this, take care to switch it when the bike is not using maximum power.

    Parallel wiring: The idea here being that you would put another battery in parallel. Generally this is strongly discouraged on bms protected packs unless you are unplugging them from eachother when charging, and are making sure both batteries are identical, and both batteries are same voltage at time of connecting them. Given that this would be difficult to meet these requirements there is another way you might go by using a diode to block current from flowing back into the other battery. This page goes over that in more detail. For a working example of this idea in practice, see this page.

    Theoretically you could use Luna remote switches on each battery in that parallel circuit, and switch back and forth by turning the one battery off and then turning the other battery on. This would not be advisable due to the possibility of accidentally not turning the other battery off, which would lead to a massive influx of power which could cause a fire. It might be possible to modify a couple remotes to use the same button with a circuit to control making sure that one remote is always off before another one is turned on, but this is outside the scope of what we can advise on.

    Charging integrated battery via the charge port: This is unsafe for multiple reasons. Primarily because any second battery you want to wire up will have a discharge rate ten times higher than the safe charge rate on the charge port. This will burn out the charge port instantly and is also likely to damage the integrated battery on the bike. The port expects something like 2-3A, and another battery can put out 20-30A, maybe higher.

    Additionally, as with any BMS-protected battery the charge port is how the battery bms is reset if something trips it. So if you are charging the original battery while in use, if something like a short happens in a cell, (which normally the BMS would protect against by shutting down the battery) you may be forcing it to reset despite it not being safe to do so.

    In theory you could limit the current of the discharge on the secondary pack using some custom circuitry, so when you plug into the charge port it is not charging it at some massively high rate of current. For example something like this, which can also do CC/CV charging, an important safety consideration. However, you would still be resetting the BMS on the original battery whenever you are charging it. Do so at your own risk.


    No PAS
    Maybe PAS magnets have fallen off, or PAS disc is stripped and not spinning all the time. (updating later with technical info on opening/servicing and checking wiring connections internally)
    Removing the motor

    1st remove the non drive side crank bolt. Its really long, holds the non drive side crank arm on, and threads into the drive tube. Use a standard crank puller to remove crank.

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    2nd, pull on drive side crank arm. it will just pull out by hand, attached to a long, splined, drive tube.
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    3rd to remove the front belt ring, you will need to start by prying out the rubber seal in the center of the ring.

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    4th using standard threaded bb tool, (BB-22) turn the splined nut clockwise to remove it, it's reverse thread so it turns the opposite of normal threads

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    5th remove the 6 phillips bolts on drive side, and remove the cover and trim ring.

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    6th loosen the 2 set screws on the top of the motor, they are 3mm hex.

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    7th the motor comes out through non drive side, so push it through slowly, wiggling it as you go, I also unplugged and removed the speed sensor, this is not necessary, since it can stay in place.

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    8th unplug the 2 connectors that lead to the motor.

    There is a metal plate the 2 3mm bolts press onto. It just fits into a recess on the motor. Make sure to put it in a safe place so it isn't lost

    You can access the charge wire going into seat tube by just pushing the motor out halfway. It has a tiny XT30 connector on it, hopefully it just got unplugged if you are opening it for that reason.
    Last edited by paxtana; 07-29-2019, 04:32 PM.

    I'm curious about Shimano's new e-bike IGHs. The SG-C7000-5 is a 5 speed with a 263% range and first gear 1:1 (aiming at a 20 mph max, IIUC) and the SG-7001-8 is an 8 speed 307% with 1:1 5th gear.
    They're part of Shimano's Steps system; would it be a useful upgrade for the Stealth? I deal with hills and could be persuaded to beta test one... :-)


    • Retrorockit
      Retrorockit commented
      Editing a comment
      The 5 speed is new and was offered in Japan first, and is just now showing up on OEM bikes in Europe. It seems to be intended for the 350W 20mph world E bike market. The 1:1 first gear means it can work on small wheel folding bikes. Whether it will be offered for the 750W US market remains to be seen. It supports Di2 electronic shifting also. So maybe an automatic transmission ( they did this with a 4 speed IGH years ago).

    Can anyone confirm the sizes of the threaded holes on the seat stays above the axle? Mine appear to be different left - right. Unfortunately Luna support wasn't much help.

    EDIT - M6x1.00 - cleaned the holes out really well, then a little oil on the screws and it worked out just fine. Probably just paint/assembly crud in there.
    Last edited by purplegorilla23; 08-06-2019, 04:05 PM. Reason: Solved - M6x1.00


      Curious about replacing the batteries when they wear out, my commute is about 20 miles each way, so would charge/ discharge the bike about 300 times a year. This would be less than three years with a typical battery life? Then what’s entailed it remove/replace the cells? Would I have to pull the motor to gain access to the cells?


        MinnRider While I hate to have to say 'it depends', that would be the most accurate answer. The number of cycles you get is highly dependent upon how the battery is treated.

        See this page for a detailed rundown:

        See this page for supporting information


        • MinnRider
          MinnRider commented
          Editing a comment
          Thanks, the info on care and feeding of the batteries for maximum life is helpful. Still interested in the implied part of the question, though, once they do wear out, how difficult is it to replace them? With an external pack, it's pretty obvious and easy. Since these are in the downtube, how will I pull/replace them? I'd guess by pulling the motor and sliding them out individually, but perhaps there is an access opening on the downtube? Thanks.

        • paxtana
          paxtana commented
          Editing a comment
          You need to remove the motor and the entire thing slides out from there

        Regarding motor removal, I get to 4th and the chainring and all just spin with the BB and tool, clockwise. How do I turn just the splined nut? Not the first time I’m confused.


        • Jasdidit
          Jasdidit commented
          Editing a comment
          The picture shows how I did it. The threads are reverse, so I just used a 1/2" cordless impact driver in reverse to bbbbrrrraaaack, spin it right off. I tried using a ratchet, but that was just futile. It might be possible to use a rod through a hole in the chain ring to keep it from moving while the nut is loosened, but I had the 1/2" driver and decided to use that to prevent damaging the sprocket.

        bikedog good question. I don't have the answer but you could ask Joel, he's the agent that took those nice pics for us. He answers phones so if you give us a call and leave a message for Joel he should call you back within a business day.



        • bikedog
          bikedog commented
          Editing a comment
          Thank you. I spoke with Joel yesterday, a veritable font of wisdom he is. The impact wrench did not work for me, however, during our conversation he came up with put the rear wheel and belt back on and use the disc brake to immobilize the chain ring. Worked peachy keen swell. Joel opined that might be the factory method.

        Hi -- I'm interested in upgrading the Carbon Gates Belt Drive group set on the stealth -- it ships with 22T rear and 55T front, and I think the belt is 120T? I'd like to get more power from each rotation / go faster, but am curious what rear cog/front cog would work to these ends. The LBS says if I replace either the front or the rear, I need a longer belt. Ideally, I'd like to keep the 120T belt and simply upgrade either the rear or the front cog...from my understanding, either making the rear smaller (presumably less teeth?) or the front larger (more teeth) would be way to go. I basically want the 3 gears to mean more (right now, I tend to just stick in the third gear because pedaling in 1 or 2 doesn't feel like it gives me enough power). Thanks for your help.


        • paxtana
          paxtana commented
          Editing a comment
          No idea, sorry. As far as I know nobody has done that sort of modification

        Hey, Looking into purchasing one of these bikes. What is the recommendation for cold weather riding and storage? I intend to ride 10ish miles a day throughout winter and I have an un-heated garage. Will I be needing to bring my bike in to charge?

        Our temperatures average lows of 16F sometimes dropping much lower. I assume this might not be a good fit since its a built in battery, unless I want to bring my bike in every night.