motor options on awkward dh rig (orange 225 prototype)

[bionicdan]

I just wondered if anyone knows of a low rpm motor off the top of their head for a left drive side setup. My bike has 12mm rear through axle and 20mm front and I dont want a bb drive as I pedal allot. I can get a 49t chainring on my disc side so I guess if I use a 12t freewheel Il need a 1000rpm motor for a target of around 20mph. Not looking to break speed barriers but I would like torque for the hills and to match the old hubs 50 mile range.

This 49t chainring is the exact size of my disc so I may use it as my drive and disc. Il mount the motor above it so the caliper is clear of the chain. The back brake rarely gets used at all but legally you have to have one.

http://www.ebay.co.uk/itm/121277807500?_trksid=p2055119.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT

I like the look/weight/pancakeness of the gng but its a 3000rpm thing. I would prefer pancake shape motors to keep it slim. I dont really want motors like my1016 shapes as it may protrude too much. Max 6kg around 400-1200w. The leaf/golden motors look ok but very heavy for the power and size. Bht do a bldc but cant find much info on them. A 500w quick release hub woulb be easy to fit in the rear with some drilled 12mm alu bar but I can only find 250w ones (probably due to the average user not taking precations regarding axle spin).

ps its pink for my gf but I know I am gonna end up stealing it when she isnt looking ha ha

 

[Tench]

Hi, if you decide to go with a hub motor I have an Orange Sub5 swingarm with a conventional dropout going spare, it looks to me like it would be a drop in fit on your frame?, finished in the original silver and good condition. I bought it to use on a bike I am building but decided to go with a complete frame and swing arm scratch build.
it would get you around your 12mm through axle problem.
It is on my put it on ebay pile!

 

[bionicdan]

Hi, cheers for the offer but if I decide to go hub motor I am going to run a 10mm disc grinder down the axle slot so I can pop a hub in and fit some custom slim half moon keys to stop any chance of torque twist.

Just trying to find some motors that dont require frame mods if possible first. I would be happy with a little 350w motor but me and my gf do 50 miles per ride and she would cry if it had less than a conhis 500w for the monster uphill on the last leg home.

 

[crossbreak]

the MAC and Bafang BPM eat hills if they are not too long and too steep... you can test using the ebike.ca simulator if you know the length and elevation of your hill.


The only motor that i know that needs only single reduction are the bare GNG (no idea where to buy) and the one we already talked about that need VOLTS.

First you should ask yourself if you wanna find a motor ($$$) to match your chainwheel ($) or if you better do it the other way around.

For your demands: 50kph, 26" wheels, 36V, 49/12T reduction: 400rpm loaded @ the wheel, 4.1 :1 reduction, 1640rpm loaded motor speed. Motor KV: 61

So you need to find a motor that has 61KV exactly. Good luck the only one that i have in mind is a bare GNG motor (no idea where to buy it). You could buy a GNG kit and throw away the belt etc... mount your own sprocket. that should work fine.

 

[bionicdan]

Ah yes it was 50 mile range im looking for not 50 speed lol.

If you look at my rear drop outs they are 135 internally but about 210mm in total. Even if I threw a 10mm grinder down the slot a hub motors threads wouldnt protrude enough (at least not on my mac or conhis).

49t sprockets are the same diameter as my disc and almost as big as you can buy easily. Any bigger and it may foul my frame. So I picked that one up for free and doesnt matter if I use it or not. It could double as my disc and drive sprocket if needed.

I may make a new hollow axle for the mac so I can slide a 12mm bar through into my frame. I would need a custom torque arm of course, and slots on one side of the axle to allow for wires and or shave some material off the 12mm bar.

I may even gut the mac and make something crazy and use a freewheel in place of the planetary gears.

I wish I could buy a motor like the mac stator only but dont know where to look

I like the look of these new gimbal closed motors and they did do a 200t one (lower rpm?) but cant see it now. Iv seen some say 600w nominal at 30kv. There is two my1016's in the garage and its looking increasing likely I am just going to have to put them on with a super noisey 9t/89t combo

http://www.dys.hk/Product.asp?BigClassName=Gimbal%20Brushless%20Motor