Looking good man.

Very nice. Yes, 7075 is really tough stuff, but that's why I like it! :mdr:

You are going to use washers on the motor mount screws, right? :wink:

Thanks! Uhhhh, I didn't think about using washers for the motor actually but it might be a good idea indeed! :) I should have some 5mm washers laying around here, somewhere lol... need to find them first.

Nice project.
 

Your project is looking good. I will be truly interested in how exactly you set this up, and of course how it all works together once you get her going. Good machining work for a basement job as well. Very ambitious adventure. Our 14 year old son is also trying to get me to help him build something like this, but I told him he needs to save up some money if he plans to get involved in anything of this nature. What is your total investment so far on this?

Thank you Jerry. On page 2 I posted a 3D model, the driveline will look like that and will be mounted to the frame. Above, on the pictures, you can see a one-way bearing with normal bike size #25 pitch, this one-way bearing sprocket will drive the sprocket which is between the cranks. The rest of the driveline - to the wheel - will be like a normal bike. (It's hard to explain, especially because my English isn't that good. I hope you understand it, if not, just ask! :))

To be honest, I didn't expect it to be so expensive. Small things like the 2 one-way bearings costed me $160, which is quite expensive for some bearings imo. Just costs I overlooked... A rough estimation: €1500 (about $2100) including everything except the bike itself.

Great to hear your son wants to do something like this. Sometimes it's really frustrating for me, I never did something like this before (I'm 17 myself) so it's very new for me too. But everytime I finish something (painted the bike, made the driveline etc.) I get a huge smile on my face which is awesome and keeps me motivated! :mdr:

Wondering out.
 

The wife and I just returned from wondering about for the day. We just hopped on a few buses and trams and found our way to a shopping center near the Czech airport. That gave us a chance to sit down and eat some chinese food after getting a haircut, and than basically do wome window shopping. I just happened to go into a moto sports shop to look at some of their quads, and dirtbikes. BUT guess what I found there. It was a "Giant" brand mountain bike already converted into a 25mph E-bike. The price tag was about 23,000ckz, wich converts to approximately $1300 US. That was the price for the whole bike with motor, ESC, batteries and ready to ride out the door. It had a rear power hub that looked pretty solid and had a very clean look about it. The batteries and equipment were mounted in a solid aluminum sort of box that was mounted vertically on the center post of the bike just under the seat. It had a thumb throttle and two wheel disc brakes. Not too bad for the price, don't you think? The mechanism was kind of like what you are working on now and all looked very professionally done from what I could tell. Something to think over I guess. I wish we had our camera so I could take some snaphots of it to share on here. Oh well.

Oh yes, you live in Prague, I've read your thread about MGM :) That's nice idd! Especially the two disc brakes. 25mph is quite fast too!

You should have a look at http://www.stealthelectricbikes.com/, they make crazy fast downhill E-Bike's, with lots lots of power. But the pricetag is about 5 times higher than yours...

Byte, those Stealth Electric bikes are $10 000 including shipping. I know 'cause I asked.

I didn't posted since 2 months... shame on me! But I'm very busy with school, so I can't work much on my bike. Anyway, last week I had some spare time and this week too so I made some progress. (Excuse me for these crappy pictures, they're made with my mobile)

I finished (95%) my battery box, made from 5mm some kind of "black mirroring" plexiglass. My 4 LiPo's should fit in there perfectly and I will mount the ESC under the ESC :)

http://img860.imageshack.us/img860/6...0610160854.jpg
http://img832.imageshack.us/img832/7...0610160941.jpg
http://img23.imageshack.us/img23/453...0610161025.jpg
http://img89.imageshack.us/img89/857...0610161117.jpg


And right now I'm working on the 2 mounts for the motor. Also made of 7075 aluminium.
http://img269.imageshack.us/img269/3...0608193802.jpg
http://img705.imageshack.us/img705/1...0610164536.jpg
http://img714.imageshack.us/img714/5...0610164612.jpg

I will try to get these mounts finished asap and make some high quality pics of it!


- Patrick

Those Giant bikes are really good quality here in Europe, you should check them out, if you did not made it already.

Battery box:


http://img696.imageshack.us/img696/755/img3208k.jpg
Front-top

http://img215.imageshack.us/img215/7131/img3210ky.jpg
Back-top

http://img801.imageshack.us/img801/673/img3211c.jpg
Inside

http://img34.imageshack.us/img34/733/img3212lm.jpg
Closed

http://img638.imageshack.us/img638/772/img3214d.jpg
CC ESC mounted underneath the battery box, I like this design

http://img225.imageshack.us/img225/8789/img3215x.jpg
Battery connectors

http://img813.imageshack.us/img813/2743/img3225u.jpg
Frame mounts

http://img232.imageshack.us/img232/9641/img3227x.jpg
Closer view

http://img21.imageshack.us/img21/9880/img3228m.jpg
Put some soft foam in it to protect the frame

Mounted the drive on the bike, and I'm very very very lucky: about everything fits perfectly, the mounts feel very solid but I need to drill out a few pieces out of the mounts to get it fitted 100% perfect. I set my alarm for 8AM tomorrow and I plan to start working at 9AM till 12AM, take a brake and start working again at 2PM till I get tired hehe. Maybe I could make my first testride tomorrow? (With video ofcourse!) I'm so excited about this! :mrgreen:

http://img695.imageshack.us/img695/194/img3231x.jpg
http://img163.imageshack.us/img163/3411/img3232f.jpg
http://img809.imageshack.us/img809/8324/img3233g.jpg
http://img28.imageshack.us/img28/1198/img3234m.jpg
http://img546.imageshack.us/img546/1509/img3236j.jpg

Looks really nice!! It's coming together!!

I was so tired yesterday I wasn't in the mood to post here... Anyway, yesterday I woke up at 8AM, started working on my bike at 9AM. The first thing I started to do was drilling out the bore of the motor sprocket to 12mm, it was very hard steel so it took me some time. The result? Horrible.
The hole I drilled was not in line, the sprocket is useless. At afternoon my dad came to help me, as a lot of things are almost impossible to do alone. My goal was to make just a little ride on the bike, so I wasn't working very secure and solid as I had little time left. It was 9PM at that time and I started ductaping all things together, I was very tired. Even though the sprocket wasn't drilled in line, I still placed it on the motor as I just wanted to see this thing turn. In the mean time I concluded that if I would make a test ride, the battery box could fall off, the chains will probably flying everywhere etc. So my goal changed to power up the motor on the bike. At about 10PM the bike was completely assembled... I plugged in the batteries while my dad was holding up the rear wheel, twisted the throttle a little and the motor started running, all the sprockets were running, everything worked like it should do. Wow, I'll never forget that smile on my face at that moment, it was so big! :mrgreen: That feeling I had... goosebumps... just because the rear wheel was running by motor, oh damn that was great! hehe If I would have make a test ride something would have been damaged probably, so I decided not to do that. It will take some time to make everything perfect before I make my first testride. I just want to have everything very solid and perfect. Anyway, a pic how the bike looked yesterday night:

http://img708.imageshack.us/img708/6302/artsd.jpg

After that I went to sleep and waked up today at 1PM lol, I'm 1 hour awake now. In a few days I go on holiday again, so it might take a few weeks till I make my first testride :(

Great work man. I'm really digging your battery box.

Great work
 

I really enjoyed your machine work and fabrication process, but your drivetrain design seems a bit over complicated for my taste. When you compare what you have done on your project, to the readily available and hugely simplified hubs that are on the open market I doubt many people would want to go in this direction. I to think you are going to have a lot of issues with chain problems, and getting your electronics setup properly in order to get this E-bike working to a level that you will enjoy riding it. Still your machine work is pretty cool, and it appears that you can do just about anything to fabricate a workable solution. Not sure what this setup has cost you, but when you can purchase a chinese hub kit for under $500 and easily convert a montain bike in one day to a powered 25mph vehicle other options are likely to fall short. The major cost in any E-bike project is the battery setup, which one can spend anywhere from $500 to $2000 depending on what type and voltage one wants to use, and how fast they want to go. As long as you enjoy your work that is the main thing. Have fun and I always lean towards what I learned in my younger days, which is KISS. "Keep It Simple Sir".

Hub motors have their appeal, but personally I think this is a much better setup. An RC motor has way more power than most unmodified hub motors. You also have the advantage of multiple gears with this setup, which is awesome for climbing extremely steep hills or just riding at peak efficiency. Flying down the street shifting though the gears like an F1 driver would be sooo sick! :intello:

If I had access to the tools and had the skills to build an RC bike I would be all over it. :smile:

I get it.
 

Yea I get the appeal and would probably do the same sort of thing myself if I had the machining equipment, but with us moving every few years from country to country it is jsut too much hassle. As for the difference between hubs and this setup it kind of reminds me of when I first started into the Maxx line of R/C's and reading why everyone wanted to get rid of the tranny setup and install a center diff instead. It simplifies the setup, and makes for less things to go wrong. Less maintenance, and the only chain to deal with is the bikes original chain. Just too many things to go wrong in lew of only having the hub to deal with. Believe me I love the mechanics of our hobby, and wish that I had the equipment to do some fabrication of my own some days. This particular setup just looks like too much trouble, which may turn out to be a maintenance nightmare.

On a side subject I contacted a friend of mine who lives here in DC(where we are this week) who is also a huge cycling fanatic and has a carbon fiber bike valued around $10K. Well at least it used to be worth that. He was going down hill at approximately 30-40mph when a (lady driver) car passed him on the left and then cut directly in front of him turning into a parking lot leaving him nowhere to go. He always wears his helmet and flourecent/eluminated vest for safety, and it was in braod daylight. He hit her passenger side and flew 18-25 feet into the air according to witnesses. The last thing he remembers was the lift-off, but he landed in grass shattering two vertibrey and required two delicate very lengthy surgeries to fuse the bones, remove bone paritcales, and repair the damage. He might be out of the Hospital this evening, but is in for some seriously long therapy to try and overcome this event. His bike was trashed as it shattered into a million pieces. Of course the woman did not see him, so she says. Probably talking on her cell phone. Everyone is doing that here even though it is against the law. We have seen people texting while going 70mph on the highway.

IMO this bike should be better than the hub-versions when its all worked out and perfected. Takes more time and care, but I love the setup!

PS: Just wear a rubber band around your pant legs so they do not get drawn into the chans and such.......

TG