Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

hzoltaan · 02-03-2012, 08:37 AM

Hi,

I thought I build an elecric bicycle before I jump head on into converting a motorcycle just to see how it works... I decided to have a "blog" here.

I'll try to keep it cheap.

Things I'd like to achieve:
- to go to work.

I live in a city... (well, a few cities built together in a huge industrial area) and I live some 14kms from work. getting to work by bus or train is some 90 minutes, with the bike it could be a little less. I could charge (at least partially) the batteries at work, so they will have to be able to give me some 20-25km range.

So far the idea is:

- bike: a simple Dutch roadster, slim tyres
- motor: 12V power steering motor (because it's cheap and I trust it more than the chinese motors one can find on internet.) the idea is not mine, I stole it from Julian Edgar, I hope he does not mind. ( Browser Warning)

- batteries: 2 x Greensaver 12V 20Ah/2Hr, I found them on internet. They were new/old stock sitting in a warehouse for three years where they were recharged every 6 month. (so the seller claims) they arrived in original packaging with 12.80 v so it does look promising. I hope they are in good shape.

- drivetrain: I was considering friction drive, but If I can manage I'd like something better. The huge ratio between the rpms of the motor and wheel makes a simple chain connection hardly possible. I found somwhere that the gearbox from an angle grinder was used. I checked mine, the ratio is 1:3.08, which could work with a 1:4 - 1:5 chain transmission. I do not know if the angle grinder gears will be able to handle the torque, and also I could not find exact data on steering motor RPM, so I'll have some shooting in the dark here.

- controlling elecrics: copy of Julian Edgar's... I plan to pedal up to a certain speed where I can engage the motor on 12V and we'll see how fast it will be able to go. I think for shorter periods 24V (batteries connected serial) will do no harm. So the bike will be definitely hybrid :Start and acceleration with human power, keeping the speed with electric. I plan to put two small buttons on the handle and a pair of relays by the batteries. Wireing will be simple. I think I will get an ampermeter and voltmeter to check and test the operation at least at the beggining.

Calculations: I used Bicycle Speed (Velocity) And Power Calculator to check what power I need. Assuming, that the steering motor will be able to give me 200-300W, it should give me some 25km/h, which is quite ok. Will see, how it works.

Any Ideas, Recommendations?
(If this works, I might step forward to buy an old palett lift and convert my GS450 which has a half dead engine anyway...

)

02-03-2012, 08:37 AM	#1 (permalink)
hzoltaan EcoModding Lurker Join Date: Jan 2012 Location: Poland Posts: 33 Thanks: 0 Thanked 0 Times in 0 Posts	Electric bicycle building Hi, I thought I build an elecric bicycle before I jump head on into converting a motorcycle just to see how it works... I decided to have a "blog" here. I'll try to keep it cheap. Things I'd like to achieve: - to go to work. I live in a city... (well, a few cities built together in a huge industrial area) and I live some 14kms from work. getting to work by bus or train is some 90 minutes, with the bike it could be a little less. I could charge (at least partially) the batteries at work, so they will have to be able to give me some 20-25km range. So far the idea is: - bike: a simple Dutch roadster, slim tyres - motor: 12V power steering motor (because it's cheap and I trust it more than the chinese motors one can find on internet.) the idea is not mine, I stole it from Julian Edgar, I hope he does not mind. ( Browser Warning) - batteries: 2 x Greensaver 12V 20Ah/2Hr, I found them on internet. They were new/old stock sitting in a warehouse for three years where they were recharged every 6 month. (so the seller claims) they arrived in original packaging with 12.80 v so it does look promising. I hope they are in good shape. - drivetrain: I was considering friction drive, but If I can manage I'd like something better. The huge ratio between the rpms of the motor and wheel makes a simple chain connection hardly possible. I found somwhere that the gearbox from an angle grinder was used. I checked mine, the ratio is 1:3.08, which could work with a 1:4 - 1:5 chain transmission. I do not know if the angle grinder gears will be able to handle the torque, and also I could not find exact data on steering motor RPM, so I'll have some shooting in the dark here. - controlling elecrics: copy of Julian Edgar's... I plan to pedal up to a certain speed where I can engage the motor on 12V and we'll see how fast it will be able to go. I think for shorter periods 24V (batteries connected serial) will do no harm. So the bike will be definitely hybrid :Start and acceleration with human power, keeping the speed with electric. I plan to put two small buttons on the handle and a pair of relays by the batteries. Wireing will be simple. I think I will get an ampermeter and voltmeter to check and test the operation at least at the beggining. Calculations: I used Bicycle Speed (Velocity) And Power Calculator to check what power I need. Assuming, that the steering motor will be able to give me 200-300W, it should give me some 25km/h, which is quite ok. Will see, how it works. Any Ideas, Recommendations? (If this works, I might step forward to buy an old palett lift and convert my GS450 which has a half dead engine anyway... ) Last edited by hzoltaan; 02-03-2012 at 09:02 AM..