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  1. marka-ee

    EZ Rider Kit - popped one open to see what's inside (Brompton conversion)

    I know what you mean by ruining the elegant folding bike by burdening it down with all that extra weight. My solution would be to put the battery in my backpack and then use the smallest motor I can find, 250 watts as you have noticed is actually plenty. The idea is just to take the edge off all...
  2. marka-ee

    EZ Rider Kit - popped one open to see what's inside (Brompton conversion)

    I've been considering getting a high quality small folding bike as well. Either a Brompton or a Birdy. Is there any small mid-drive kit that might actually work with one of these? Maybe with a little extra welding? My advice to you on your controller is just replace it entirely with some other...
  3. marka-ee

    Cannondale Moto FR suspension forks. Why did Cannondale saw off disc brake mount?

    I'll try to take a picture of the area tomorrow, but in the meantime they were definitely amputated because the area of the mount definitely protrudes several millimeters and there was an intention to put something there, but then surgically removed. If I can't weld something to the protruding...
  4. marka-ee

    Cannondale Moto FR suspension forks. Why did Cannondale saw off disc brake mount?

    I recently purchased some used Cannondale Moto FR suspension forks. These are the ones which use needle bearings in both sides thereby highly reducing any static friction, which is sometimes called stiction. One peculiar thing about these, and I've seen other examples with the same situation...
  5. marka-ee

    RC Drive Recumbent Trike Build

    If you're referring to my question about modeling the stress on this type of pulley, I think it's a very difficult problem for any level of engineer. The problem is that the loads on the teeth are one level of complexity, but then the side-mounted nature of the pulley, and then the fact that...
  6. marka-ee

    Great test of different sealants in motorcycle tires

    These tests are rather useless and here's the reason:. These substances change their properties after a few days or weeks and the effective nature of what might work when it's brand new changes substantially. I have found this to be the case with slime and also Stans, which is a latex-based...
  7. marka-ee

    RC Drive Recumbent Trike Build

    Yeah, I've been 3D printing for more than seven years now. My next 3D printing project will be CADing up and printing the 20 inch toothed belt pulley for the back wheel of my trike. It's going to attach to the side of the rim. Modeling the stress on this is very complicated so I'm just going to...
  8. marka-ee

    RC Drive Recumbent Trike Build

    I'm just curious how much filament you went through so far on this project.
  9. marka-ee

    is geared hub motor feasible in a 20-inch rim?

    For what it's worth, it's not a home-built trike. It's actually a Optima Rhino FS, which is full suspension but not the terribly fancy kind with double A arms on the front however it does ride very well from what I can tell. They only made a few dozen of them. When I get the time I'm going to...
  10. marka-ee

    DIY powerwall 14s100p 18650s DIYBMSv4 currently running

    Is this a power wall or is it a battery with a charger and or inverter attached? There is a difference.
  11. marka-ee

    Observations from a new to tadpole trike rider.

    The problem with both flea markets and secondhand stores is now they look stuff up on the internet to get closer to the actual value. In the old days, they probably would have sold that weird bicycle for $100. I consider myself lucky to get my full suspension trike for $1200 recently.
  12. marka-ee

    Observations from a new to tadpole trike rider.

    Back to my trike topic, I did notice that when I was doing my speed test with the direct drive motor that the 48 volt battery pack I was testing with was rather saggy. It actually sagged down to about 41 volts. So the first thing I have to do is get a real battery pack on there and test it...
  13. marka-ee

    Observations from a new to tadpole trike rider.

    I'm fully aware that the world is supplied by the Chinese. What I'm talking about is when we are purchasing things such as hobbyist electronics devices or other more esoteric things, the Chinese are very inaccurate often on the specifications. Take for example 18650 lithium cells. I go around to...
  14. marka-ee

    Going from hub motor to 3000 watt belt drive. A good idea or not?

    I have rear suspension and my rear tire is 2.12 wide which is the widest I can fit.
  15. marka-ee

    Ring gear / drone motor Ebike prototype

    So to mitigate this as much as possible, the goal would be to use an idler bearing with the largest diameter feasible. I think I have this correct. Secondarily, it's best to use the largest pulley on the motor as well. The overall limiter on this is to get the largest possible pulley onto the...
  16. marka-ee

    KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)

    It's been a few years since I've looked at this thread. Can anybody tell me what the overall stability is of this software these days or is it still in a very experimental stage? I would primarily be interested in it for its field strength weakening as a possibility to increase my speed maybe...
  17. marka-ee

    Ring gear / drone motor Ebike prototype

    I'm not understanding the loss of efficiency of having an idler roller on the belt. Would that simply be a matter of the bearing spinning drag? For me, it doesn't matter how close the motor is to the wheel. So I can envision having a belt wrap around slightly more than half the motor pulley and...
  18. marka-ee

    Linkage Mechanism- any engeneers here?

    true, the dominant factor: "patents". I remember seeing somewhere a very elegant folding bicycle design that got held up because of a patent issue. I can't put my finger on where I saw the design but when I saw it as an engineer I thought that it was extremely elegant.
  19. marka-ee

    Ring gear / drone motor Ebike prototype

    What did you mean by 'requires high tension' ? Does that mean that you needed a lot of belt tension so that it doesn't slip on the small pulley side? Can you comment on the noise of the belt versus the gear version? If I'm not mistaken, the AT-5 belt has 5mm pitch. Isn't that too fine for this...
  20. marka-ee

    ebike's working logic

    你真的认为如果你用中文发帖，你会在这里得到答案吗？这显然是一个英语论坛。 Translation: Do you really think you'll get answers here if you post in Chinese? This is obviously an English language forum.
  21. marka-ee

    Observations from a new to tadpole trike rider.

    It's a Chinese kit, so as everybody knows, even if they did state a maximum speed, it would be in what I call Red Chinese units, which mean nothing. It came with its own controller, so that's what I tested with. getting the red Chinese kit was fairly affordable. Other options would have been...
  22. marka-ee

    Observations from a new to tadpole trike rider.

    Well, I received a direct drive 20-inch hub motor hoping that it would go faster than the small 250-watt Bafang hub motor that I was testing with. But alas, it's not the case. In fact, the direct drive hub motor at 48 volts is getting the exact same top speed as the small geared hub motor that...
  23. marka-ee

    birdy bike

    Most hub motors would have a problem with that bracket that intrudes into the space between the dropouts. By the way, I really like that suspension design. I'll bet it's really smooth on even the smallest bumps.
  24. marka-ee

    belts: Gates vs Optibelt ?

    That's true. Now that I think about it, I could create the 3D model so that it fits the angles of the spokes exactly and also the curvature of the rim so that it is a very snug fitting system. Then, maybe even simple tie wraps, multiple per spoke, could be used to fasten it. However, I'm still...
  25. marka-ee

    belts: Gates vs Optibelt ?

    , which is less noise prone than direct gear. Also, this video is very good. I like the design Tom did on the second video. He has gone through many revisions. Although I'm thinking of somehow attaching it to the rim instead of the disc hub because I want to go as big as possible. The...
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