My First Build - Pics And Questions

Hey everyone I'm getting started on my first electric build, I've built a gas bike before but I'm wanting to put together an electric to ride on the bike paths... you get tired of the loud 2-cycle engine noise after awhile. I've decided to put together my own system using a large 36v scooter motor. I will also be using a controller pulled from an electric scooter. As you can see in my pics below I plan on mounting the motor on the downtube in front of the crank. I plan on putting together a front freewheel so the pedals won't spin when using the motor. I would love to have a dual front freewheel, but after doing some research here and and on google I don't think anyone sells components to easily make a dual front freewheel. From what I've read the only place to get semi-inexpensive parts to build a front freewheel is here: http://www.sickbikeparts.com/catalog/index.php?cPath=21&osCsid=eb2665b9bd0b9a0d057357d5f359fbec is that the only place? Or is there somewhere better/easier/cheaper? OK so on to my questions... First of all I don't understand how to build a front freewheel with the parts listed on that page. Which specific parts do I need? I have never taken apart bicycle gears/cranks/shafts so I'm a complete noob in this department. If I buy the right parts from that page are they all going to bolt together and install without me having to weld or do anything hard? Is it that simple or will it require more work than I'm thinking? My next question is will I be able to find a sprocket that fits on this motor that will fit a regular bicycle chain? The motor shaft is shaped to fit a sprocket with a dual D-bore like this:


So I'm thinking if I can put together the front freewheel crank setup, find a sprocket for the motor that I can use with a bicycle chain, and figure out a good way to mount the motor I'll be set. The motor is just taped on right now so you can get an idea of what I'm thinking. Do you think this setup will work? Am I missing anything? I realize that when I'm pedaling only I will have added drag because I'm turning the motor, I am fine with this. That is unless I had a dual front freewheel, I don't think that is available anywhere though.

Ok so give me some tips Sphere! I think the hardest part for me is goung to be setting up the freewheeling front crank so the pedals don't spin when the motor is running. Any insight here would be MUCH appreciated. Here are the pics:

Basically you are looking at a "Cyclone" build. That name is a brand of bike motor system that does exactly what you're wanting to do, except that I think the higher wattage versions use a planetary gearset on the motor itself to reduce it's speed and increase it's torque, and I think they have a freewheel on the motor shaft to prevent having to turn it when only pedalling.

I'm not sure exactly which parts on SBP you'll need to do this, but if you check some of the Cyclone threads around here you will probably see enough to tell you.

I burned up a similar Unite motor in a couple of weeks, so pay attention to any odors or smoke from the motor, and feel the motor often after use. If it starts to burn the varnish off of the windings then the gearing is too high, so take it easier.

Looks to me like the motor is going to touch the wheel when you hit a bump. You'll go flying over the bars and break both collarbones like I did when I got a waterbottle into the front wheel. So get a rigid fork on there, or move the motor closer to the crank, whatever gives you the clearance you need.

You probobally realize it already, the pics look like you are just in the early mock up stages.

Basically you are looking at a "Cyclone" build. That name is a brand of bike motor system that does exactly what you're wanting to do, except that I think the higher wattage versions use a planetary gearset on the motor itself to reduce it's speed and increase it's torque, and I think they have a freewheel on the motor shaft to prevent having to turn it when only pedalling.

I'm not sure exactly which parts on SBP you'll need to do this, but if you check some of the Cyclone threads around here you will probably see enough to tell you.



I have a cyclone setup and the freewheels they sell are pure junk. The freewheel crank from sickbikeparts is far superior! I have been through 3 of the "cheap" Cyclone freewheels (Lida ??) and only one that sickbike parts sells, plus the bearings can be replaced if and/or when they go out. It has been talked a lot about on this forum so search for it. Cyclone is a good setup otherwise though, I like it a lot and have put 2000 plus miles on mine.

From Sickbikeparts you will need the HD freewheel, 2 main sprockets, the bolt kit for the sprockets, and the 2 crank arms.
You may also want to get the crank spindle they sell for the Starter option. its extra wide and off set to the left so your left foot peddle will clear that motor.

But you may have a problem still. I think that motor's rpm range is too high to go straight to the crank sprocket. I think you will need a reduction gear between it and the crank.

Go to the "non-hub" resources sticky. Look for Miles' freewheeling crank links (link added below).

If a BMX bike has a freewheel on the rear wheel hub, the tooth-count on the rear-sprocket can only go so low. By moving the Freewheel to the Bottom-Bracket (BB, the pedal-axle)), the rear cog can be much smaller (also requires the rear cog to be 'fixed' and no freewheeling). This means for a BMX that the BB chainring can also then be smaller (while maintaining the same ratio) for more ground clearance on stunts. Such bikes are called "trials" bikes, so a trials-crank set ($25) will accept a generic freewheel.

I haven't done this (just read about it) so buyer beware...

http://endless-sphere.com/forums/viewtopic.php?f=28&t=7192#p165215