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  1. B

    electric bicycle as college project, couple of questions

    Not sure on the weight of the bike but it's pretty heavy as the my1020 motors weigh a fair bit. The reason the whole reduction system is mounted so high is because of the width of the thing, it would hit the pedal arms if mounted any lower so would make pedalling impossible. I agree the...
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    electric bicycle as college project, couple of questions

    Hi everyone just a couple of pics of my built bicycle. It achieves around 25mph using 4, Turnigy 11.1v 2200mAh batteries in series to give 44.4v or 48v+ hot off the charger. The only problem is they run out too quick as my 48v 1000w electric scooter controller must have a cut off at 42v...
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    electric bicycle as college project, couple of questions

    Ok will have a look round at others projects and see where they have positioned things. Just that if mounted where i wanted it, in the middle of the frame the motor may extrude out either side of the pedal assembl,y and therefore would make pedaling or infact just using the pedals as foot rests...
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    electric bicycle as college project, couple of questions

    Have just drawn up the reduction system based on the one i found on this forum earlier in my topic. The funny looking part on the right hand side of the jack shaft is a bicycles rear wheel hub cut in half and the freewheel adaptor part is retained so that a bmx freewheel sprocket will screw on...
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    electric bicycle as college project, couple of questions

    Thanks for the link, yeah i could use that but since i've just butchered a bicycle hub and got the cassette freewheel holder part i will try and use this. Basically i just cut the actual wheel hub in half and the internal diameter just need boring a little to fit my 20mm jack shaft. Only...
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    electric bicycle as college project, couple of questions

    Right, i thought that bmx freewheels on the rear wheel hub were left handed threads. But when you take a cassette of a mountain bikes rear wheel hub you have to unscrew it counter clockwise so therefore the thread is the other way round to that of a bmx's hub i thought, but as you just checked...
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    electric bicycle as college project, couple of questions

    Thanks for the info. Just out of interest do you have any pictures of your assembly. I'm not sure if a bmx freewheel will screw onto the cassette type freewheel adaptor hub part as the cassette screws on clockwise whereas bmx freewheels are left handed threads, so would this mean i need a bmx...
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    electric bicycle as college project, couple of questions

    Yeah i mean the threaded part which the cassette screws onto on say a mountain bike. What i was going to use it for is to secure a freewheel onto the motors reduction systems jackshaft by building/constructing a part to weld or secure on somehow to the freewheel adapter using the side where the...
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    electric bicycle as college project, couple of questions

    Thanks for the help Bandaro, so what i'll do is take the complete shaft out of the motor and then have both of the steps machined down to accept an 8mm or so thread (same as the original thread but just longer) to hold the pulley on properly. Failing this, i thought i could machine out one end...
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    electric bicycle as college project, couple of questions

    I've got my belt with pulleys and a bicycle pitched sprocket to mount to the jackshaft but have come to a problem. The problem is that the smallest pulley which attaches to the motor will not be able to fit to the motors shaft properly. This is because there is only a small amount of thread from...
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    electric bicycle as college project, couple of questions

    Thanks for the heads up. I'll be using a bicycle chain as the sprockets on the freewheel crank are the 1/2" pitch which i think bicycle chains are? When i get it all assembled i will see whats what and go from there if anything needs altering. Evan.
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    electric bicycle as college project, couple of questions

    No worries, yeah crank part with the pedals, thought i was doing something wrong for a minute, as it took me a while to figure out the crank rpm calculations :D Will post up some pics when i've got the reduction system constructed and the parts arrive. Evan.
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    electric bicycle as college project, couple of questions

    The reason for choosing the 24:1 reduction ratio to the crank is so that i can get a crank rpm of around 125, usually people on here are trying to achieve a crank rpm in the region of 80-120rpm. I am intending on using the unite MY1020 motor for a while and then when funds allow go for an RC...
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    electric bicycle as college project, couple of questions

    Pareabellum: thats a shame to hear that, hope you get it sorted soon. I've decided to go for a 12 toothed pully to a 72 tooth for the reduction (from motor) then from this i will run a 12 tooth sprocket down to a 48 tooth freewheel crank assembly. This should give me an overall reduction of...
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    electric bicycle as college project, couple of questions

    That looks great, how is the motor connected inside to the clutch housing part? I don't suppose you have used the dirt bike/mini moto centrifugal clutch attached to the motors shaft? I thought those gearboxes have cogs inside as i've taken them apart before, unless i'm mistaken, maybe i could...
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    electric bicycle as college project, couple of questions

    That should be good then with 50mph+ top speed. I didn't make the above motor reduction system pictured as i found it on here and wondered if i could do something similar. Have you got the right topic? Evan.
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    electric bicycle as college project, couple of questions

    Yeah i will be upping the power at a later date to achieve a better top speed and a little more torque. I have found a video on youtube showing a bicycle here in the UK using the My1020 motor connected straight from the motor to the crank via chain and sprockets and went fairly well, that why i...
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    electric bicycle as college project, couple of questions

    Right i've decided to go with the MY1020 1000 watt 48v motor for now just as a starting point and then possibly upgrade to an RC motor at a later date. I am going to run a belt reduction system and then to a chain setup to drive a freewheel crank, but need some help on the reduction ratio to...
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    electric bicycle as college project, couple of questions

    Thanks for the info, 40mph is good even with pedaling! That controller you made sounds very tempting if it doubles the input voltage to the motor. I may look into this further. As for the motor, i'll probably stick with the one in the link as i can get it here in the UK, so parts availability...
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    electric bicycle as college project, couple of questions

    Thanks for all your help everyone. Yeah i know i said i would like to do 40mph+ but now i'm thinking realistically with budgets and after all, it's a college project so improvements can be documented and acted upon at a later date if need be, so as long as it does 30, maybe 35mph if i'm lucky :)...
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    electric bicycle as college project, couple of questions

    Well i would like to go down the brushless route but the only problem is Turnigy are out of stock on most of the good powerful motors so thats why i turned to the relatively cheap and powerful MY1020 motor (48v 1000w). I was wondering what controller and throttle control to use, i was thinking...
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    electric bicycle as college project, couple of questions

    I've been thinking of using one of these electric motors, 48v 1000watt and i think used for electric scooters. Would it be suitable if a reduction system is added to achieve a good speed or are they just not that powerful? I haven't found many people using these motors, only on youtube bikes. So...
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    electric bicycle as college project, couple of questions

    Yeah there is a machine shop at college so any work on a lathe etc could be achieved. I been thinking of getting a disk braked rear wheel to bolt the sprockets onto for a direct drive, i think i may go down this route as it seems a bit more easy and that way i can make my own reduction system. I...
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    electric bicycle as college project, couple of questions

    Well i may use a pocket bike gearbox or possibly construct my own reduction system as they don't seem too difficult if using say belts and then a chain setup to the wheels/crank. I haven't really looked into 4QD controllers that much so didn't realise they weren't for brushless motors, i have...
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    electric bicycle as college project, couple of questions

    Andje: I have got a basic front suspension bike but not with a disk brake, about 2 years ago i made a petrol powered bicycle and it used a midi moto 49cc pull start engine and achieved a genuine 41mph in the 1st gear of the bike (gearing was way too high), this bike had no suspension and no disk...
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