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Mountain bike electric conversion

August 08, 2008 — BarryK
I am thinking of transferring the electrics from my electric bike to my new mountain bike -- a very interesting project, I reckon!

The electric bike is an el-cheapo from Kmart, AU$399, that I purchased about a year ago. In Australia, a power-assisted bicycle can be a maximum of 200 watts. Same in the UK. The European Union has settled on 250 watts.

The motor on my bike has a "200 watt" sticker on it, but I think it's the same one as the top pics at this site:
(the motor with the ribbing around the circumference)
That does 250 watts. I have read that the Chinese manufacturer just puts the appropriate sticker on it as per the target Government legislation requirements.



Username: John_Doe
"Barry, check out bionx (it's a hub motor system like Sage is talking about) it's probably the most state of the art system out there. I've been dreaming about having one for a year now. Induction to pump power back into the battery cell sounds pretty cool. Also, I just ordered one of these for charging stuff as I go: I've got a cigarette lighter plug with a usb slot to power up a couple of my mobile devices via a tiny USB hub while I ride (a generator like this would be silly if you have a bionx system, yet welcome on a motorless bike).

Username: ANOSage
"Avoid the zbike! Although Canadian, the Bionx seems to suffer southern-neighbour-hype syndrome. I think they mean 8Ah - that should be good for ~8miles range, perhaps. So far, I cannot get NiMH technology to work satisfactorily on my ebike - it cannot supply sufficient peaking power from spirally wound cells. Specialist Li-ion cells can do this, but not at that price and their lifetime in such an application is unproven. TMF lead-acid cells perform spectacularly in dragster bike racing, easily beating reciprocating engines on nitrous - you can get at least half-a-dozen runs out of them! As the deposed CEO of GM infamously said of the brilliantly engineered Impulse "We chose the wrong battery". There was/is no choice and therein lies the problem. I'd be happy to correspond with folks having a sustained technical interest in ebikes. Despite the economic miracle and the smog, there is still a multi-million market opportunity for ebikes in SE Asia, especially to replace tuk-tuk's and those all-purpose family shifting scooters beloved of our Indian friends; just off for a masala dosai breakfast....

Username: BarryK
"The Panther Zbike looks awesome: It's exactly what I want -- an electrified mountain bike, and the AU$1395 is quite attractive. Today I was looking around online, and that price seems quite low. Sage has reservations about the battery, and that would be a significant proportion of the cost. My el-cheapo has two 12v lead-acid batteries (in series) -- the main disadvantage being the limited number of recharge cycles compared with the later technologies (as I understand the situation). I used to have some knowledge about lead-acids, back in my lecturer days. I guess, even if it's recharge cycles are very limited, it is relatively cheap so can be replaced every year or whatever. I presume they do recycle batteries these days -- hope so.

Panther Zbike
Username: BarryK
"Ah, looking at the web page a bit more closely, maybe for AU$1390 you are only getting lead-acid batteries, as they state Lithium-ion battery upgrade is $400. Still a good price though. My el-cheapo has two 12AH 12v sealed lead-acid batteries -- it doesn't say so on the label, but I presume they are designed for deep discharge. What would they cost? -- 50 bucks each?

Controller/motor supplier
Username: lwill
"I'm not real familiar with bike convertion, but if you want to go serious DIY I ran across this company while looking for a fork lift controller. Some even do regenerative braking to help recharging. Might be a bit pricy, but if you got serious mountains, you need a serious mountain bike...

Username: John_Doe
"> Although Canadian, the Bionx seems to suffer southern-neighbour-hype syndrome. Sorry about the "hype syndrome" and btw I thought it was German for some reason. I could have sworn that when I was first looking at it (~1 year ago) that it was built in Germany. Not sure what happened. Seems from review of the current web pages that it is made in Canada now. carry on...

Tags: general