This Bike + This Kit... What do you think?

[Neo2172]

Hello! So I've never build an Ebike before and I'm wanting to keep my first build as cheap as possible. This:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140538595034&ssPageName=STRK:MEWAX:IT

is one of the cheapest rear kits I can find (unless someone knows of a cheaper one). And for less than $250 it doesn't look too bad. What do you think?
It is a 48v 500watt kit, they don't give any info on the controller...

As for the batteries I'm going to start with some lead acids I have laying around and possibly switch over to some lithium? after a few months... Any recommendations on the cheapest way possible to get around 10AH (48v) of modern batteries? I believe I read somewhere that 10AH should get me around a 10 mile range, or was it 20 miles?

Tips comments and feedback are appreciated, Thanks!!

I plan on mounting it to this bike:

 

[torker]

Seller says he will ship to US and Canada only. Are you in one or the other? Otherwise looks good. You will not like lead except it is easy and cheap if you already have them. I looked at that frame for a cheap full. suss. setup. It has 1 1/8" headset so you can upgrade the forks later. The frame is like my FSR. I made battery boxes to hook to the top bar. You might check out my posts or my photobucket link for ideas.

 

[wesnewell]

That's the same kit I bought and I've put over 600 miles on it in a couple months without problems. Using a 14s 5ah lipo pack top speed of 27mph with 270lb rider. I didn't use torque arms, so if that bike has steel dropouts it should work fine without them. If they're aluminum, use torque arm(s). Oh, the tire it comes with is only 1.75, so replace I replaced it with a 2.125 with 65psi rating and new tube. If you change the tire, install some rim tape. I used friction tape. More info here.

http://endless-sphere.com/forums/viewtopic.php?f=4&t=25375

 

[oldpiper]

Where are you going to put 48V of lead? If your answer is "on a rack behind the seatpost" and you are also going to run a rear hub motor (which most people do), then that front wheel will be up in the air every time you start off (unless you or a passenger sits on the handlebars). Keeping the weight as close to the center of the bike and down low is essential for handling, especially with that heavy a battery pack (sitting on the handlebars does also tend to make quick handling a bit more difficult, too).

Cameron

 

[FMB42]

I agree 100% with "oldpiper" about having so much weight up high and over the rear wheel. Handling will definitely suffer from this. Therefor, I would recommend that you follow OP's advice and/or use a lighter (rear mounted) LifePo4 battery. A LiPo battery would be even better (however, extra caution must be exercised when using, charging, and storing LiPo batteries).

Anyway, I purchased the 36v 500w version of your kit from yescom.com (good company, could be the same as your merchant). The only problem I found was that the lead acid battery charger was wired wrong (i.e. red/pos output = negative and black/neg = positive). This was subsequently confirmed by opening the battery charger case (the circuit board outputs have "+" and "-" markings on it).

 

[dogman dan]

It should work good enough, but carrying the battery is always a bitch. You'll break racks, and even seatposts. I beef up my seatpost with a broomstick, and then brace the seatpost rack back to the frame with steel conduit. Even with the bracing, sla's back there is going to be ugly to ride. About 15 pounds is all you want to carry on a rear rack with a rear motor. Even that will handle lousy, but it will be rideable.

Carrying lighter batteries up front is how a lot of us do it. After we get some experience and graduate to lipo batteries.

 

[wesnewell]

Maybe it's because I'm 270lbs, but I first had 22lbs of lead on the rear rack that came with the kit. Before I put and batteries on it I had my 120lb wife jump up and down on it, so the rack is solid. Anyway I didn't have any problems with the front wheel coming off the ground. Of course I don't get on it and jam the throttle either. The problem the lead gave me was the balance when getting off or on it. Other than that the bike handled fair. But it's much better now with a 3.5lb lipo pack.

 

[gensem]

this one should be also a good option

http://www.emissions-free.com/catalog/i14.html

 

[dogman dan]

Yeah, I didn't say unridable. Just lousy handling. A tendency for the frame to flex a lot and give a tail wagging the dog feeling, and a pretty light front wheel. On street, tolerable. On dirt, make you crash more for sure. But nevertheless, on any frame rear battery and rear motor is not as good as in the frame battery, or balancing the bike out with a front motor and rear battery.

 

[Drunkskunk]

+1 to what Dogman said. Also, that bike uses an Aluminum fork, so it's not good for a front motor.

The ultimate answer here is that your bike isn't good for a conversion. You'll spend more than it's worth in parts, broken parts, and headaches to make it eventualy barely adequate. What you need is a bike with an open triangle. Plenty of good used bikes on Criags list for cheap that will work better and ultimatly be cheaper than trying to make that bike work.

 

[Neo2172]

Thanks for all the reply's guys. I just won this kit: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.l2557&rt=nc&nma=true&item=250826915359&si=1mK4TXLFGOjsZIgkZptCEjh9qo0%253D&viewitem=&sspagename=STRK%3AMEWAX%3AIT

Its shipping from CA so I should have it within a week (hopefully). I have been looking into lipo and am pretty sure I'll be buying some to replace the lead within the first few weeks of having the kit. I'm thinking about going with 2 5ah 6s lipo packs from hobbyking... I'll wire them in series for 44v. I plan on buying the cheapest ones possible on HK, I would be fine with 15c --- doesnt matter if they ship from the USA or China, I can wait if they are cheaper from china. Couple questions - first, what would be the cheapest charging solution for this, I think wenswell is using the 48v SLA charger that comes with the kit and just watching the batts as they charge. But lets say I want to buy a (sub $30) lipo charger... What would I buy? Second, how far do you think 5ah of lipo will get me on a charge, I weigh 175 pounds, do you think I could go 10 miles on 5ah? Basically what is the best bang for the buck lipo battery I can get right now? I know there are some 8ah lipos out there but if they cost twice as much as the 5ah its not a good deal... what's the term I'm looking for... is it cost to watt hour? that might be the term I'm looking for. So i guess I'd want the cheapest $ per watt hour battery. It would also be nice if I could find a cheap charger that will also balance the cells.

Oh! and where is the cheapest place to get a torque arm?

Thanks guys! I'm looking forward to building this thing!

 

[wesnewell]

Looks identical to what I have. I weigh 270lbs. On 7ah lead, got about 6 miles of no pedaling. On 5ah 14s lipo get about 10 miles. With 12s, I'd guess 8 miles, but lvc may gut you off earlier. Of course if you pedal too, you can extend the range considerably. If your bike has steel dropouts you may get by without torque arms. I don't have any on my rear wheel kit. Not a problem so far with about 1k miles on the kit. HK is probably the best place to buy lipo. Probably ebay for a cheap charger.

 

[Neo2172]

Looks identical to what I have. I weigh 270lbs. On 7ah lead, got about 6 miles of no pedaling. On 5ah 14s lipo get about 10 miles. With 12s, I'd guess 8 miles, but lvc may gut you off earlier. Of course if you pedal too, you can extend the range considerably. If your bike has steel dropouts you may get by without torque arms. I don't have any on my rear wheel kit. Not a problem so far with about 1k miles on the kit. HK is probably the best place to buy lipo. Probably ebay for a cheap charger.

So maybe something like this for the charger: http://cgi.ebay.com/Lipo-Battery-Charger-Discharger-iMAX-B6-12V-5A-Power-/250820986638?pt=Radio_Control_Parts_Accessories&hash=item3a6618870e

and something like this to get the 12v: http://cgi.ebay.com/CAR-CIGARETTE-LIGHTER-SOCKET-ADAPTER-110V-AC-12V-DC-/150536508622?pt=PDA_Accessories&hash=item230cacd4ce


That would be a pretty cheap charging setup...

How exactly do you go about using the included lead charger for the lipo?

EDIT: this would probably be better for the power supply: http://cgi.ebay.com/POWER-12v-5A-Adapter-MYSTEKY-iMAX-B5-B6-RC-Charger-/250303929803?_trksid=p4340.m263&_trkparms=algo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D120686176054%26ps%3D63%26clkid%3D284701529991324165

 

[999zip999]

You can get a old comoly 21sp. bike for 60usd. so you don't have to worry about the rear dropouts. For the frame flex too. Lead will disapiont you. You can save your bike for a second. Cheap way in. Let us know how it works out.

 

[wesnewell]

I bought a Hyperion 1420i for $180 and a 600W 24V psu to power it. I don't know much about the cheap chargers, but that one is only a 50w charger, but should be ok for balancing every now and then.
I simply plug the included charger in and monitor the voltage. It's not real fast either, but convenient not to remove the battery from the bike. Takes about 1-2 hr. to fully charge my 5ah 14s pack. I usually stop charging about 58.6V, although I've let it go to 59.1 a couple of times. Battery settled under 58.8v in a few seconds. You only want to got to 50.4V with 12s. And make sure you don't forget it charging. I'm not sure what voltage it will stop at, but I know it will go to at least 60V, and that would likely cause major damage to 12s lipo. That's one of the reasons I went to 14s. I think if I had 12s, I'd buy one 60-90 minute timer plug for it.

 

[Neo2172]

but that one is only a 50w charger,

So basically it will work but it will take a long time to charge a 5ah 6s pack correct? Any idea just how long a 5ah 6s pack might take to charge with a charger like this?

 

[wesnewell]

6x4.2=25.2x5ah=126wh/50=2.5hr.