Electric Bikes - Something NEW: Sunstar SO2

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View Full Version : Something NEW: Sunstar SO2

donob08
09-11-09, 08:01 PM
This new motor drive system probably won't hit the US for quite a while, but it is worth keeping track of.

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Click this jpg. That will open another window in which you can zoom in order to read better. It looks like something to look forward to. e-assist through the gears.

The web page is:
http://64.233.169.132/translate_c?hl=en&sl=ja&tl=en&u=http://www.sunstar-engineering.com/motorcycle/assist.html&rurl=www.google.com&usg=ALkJrhh14yR6OLI1c2No34iTdpxtZ5n0vQ

They argue that it could be added to any bike as easily as changing a Bottom Bracket, would fit any/all bikes...

Our Oak Ridge National Laboratory is working on the axial gap motor concept that this uses. They think it may be BIG in future evehicles. I guess the future is now.

Let's hope half of this proves out. This is Gen 2. There was an SO1.

nwmtnbkr
09-11-09, 08:20 PM
The thing that has worried me about mounting a motor near the pedals to work directly with the chain drive is how well the chain will tolerate the additional stress. Guess I can't get the image out of my mind from a post on another forum about a cyclist riding a bike with such a setup bleeding out after his chain broke and flew into his leg, cutting deeply into his femoral artery.
donob08
09-11-09, 09:13 PM
I guess anything is possible, but these systems only increase chain tension by a factor of two. They MATCH the force the rider applies, doubling it. It's a poorly maintained bike that doesn't have a safety margin for that. What if a 250 lbs person got on your bike?

Not to criticize the injured but that bike was an accident waiting to happen. I'd like to think that for steady force a factor of ten bigger than mine wouldn't break anything on my bikes.

The Sunstar is 250 Watts of energy efficiently applied. The eZip is 450 Watts of energy. If energy is bad the eZip is more fearsome. To complete the thought, a good athlete can put out 200 watts of energy , so if a system like this doubles it, the energy is 400 watts, that's while the eZip is applying 450 watts. And because the rider with Sunstar can switch to lower gears, to a big chainwheel in back, the chain tension is lower for a given hill.

donob08
09-12-09, 08:58 AM
"A to B" the english publication has a very good article in their May 08 issue praising Sunstar. Some how news arrives in the US late.

http://www.exacteditions.com/exact/browse/392/428/3702/2/41/0/

I hope this link works for everyone. I have a subscription to "A to B" and it works for me. I'm not sure if my subscription is letting me through.

This is the company web page. Product only sold in Japan and France.

http://www.sunstar-ibike.com/anglais.htm