eBay special - good idea or bad?

neptronix

neptronix

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Hey there. Remember me? the one with the 700c bike lookin' for a little hill climb assist setup, nothing full blown.. i'm 220lbs and don't need a long commute.

Per mwkeefer's recommendation, i am getting rid of the 700c bike, and getting an aluminum mountain bike + installing a front steel fork + doing a front steel conversion.

Looking for a geared hub motor here. Was looking at the ampedbikes kit but it's a little bit over my budget right now :\

I stumbled across this on eBay ( from a company that is 5 miles away from me ), and was wondering what you guys think:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250475531832

Not sure what motor that is.. maybe a bafang?

Here's some info on the controller ( i haven't heard it mentioned on here.. )
http://njyl1.en.alibaba.com/product/257308517-209512304/electric_bike_controller.html

Opinions?
 
Are you sure you want to go lead acid?
 
I took a look at the Ebay listing and here's my input.

Total kit weight has to be wrong. A 12ah SLA battery weighs just under 10 pounds (4.5 kg). Three batteries is 13.5 kg. There is no way that the remaining components (wheel, controller, rack, etc) total to 1.5 kg.

They are very optimistic about the number of cycles you can get out of a SLA pack. Real world with deep discharge they are good for 100-150, not 300-500. I would consider it a 'starter' battery until you can get something better (and much lighter).

The range claim of 25 km is probably accurate. With light to moderate pedaling you should be able to get 15-17 miles out of the pack. With no pedaling maybe 10 miles. Remember that with SLA you are lucky to get 60% of the pack's nominal capacity. Top speed would be a bit slow for me (25 kph = 15 mph yuk...) but that's your call.

It does look like a Bafang motor although AFAIK Bafang's are not nominal 500 watt, more like 250 watt. As long as you don't over power them they are pretty good motors.

As with all EBay vendors be careful. You can spend $100-150 more and buy something from a proven reputable vendor with many good reviews from members of these forums.

Take care and be safe,
Bill
 
Hi fifth, The vender actually did spell it out about the batteries identical to what you said. They also say they are giving the batteries for free so there is no warranty on them. :wink:
 
HI,
If you search for an "hill climb assist setup" you should just forget lead acid batteries. Even if they are "given" ;)
You should really invest in a Lipo kit or better a lifepo4 kit.
then 370$ for a bafang kit is not really that cheap ;) there is on the forum some people which are selling the same at the half of the price :) (maybe without the bag :D)
Grüß,
Dodjob
 
IMHO, I think a 700c bike would be great. Put a geared rear hub on it, and mount it with excellent torque arms to protect the road bike frame.

My $0.02
 
liveforphysics said:
IMHO, I think a 700c bike would be great. Put a geared rear hub on it, and mount it with excellent torque arms to protect the road bike frame.

My $0.02
Click to expand...

+1

IMHO, there are several options for 700c out there and each one is different, make sure you have enough room in the frame & forks for beefy tires if you so desire, we have excellent roads here in the Portland Oregon area (I'm in Oregon City) so I wouldn't be afraid of 700c at all.

There are a wide selection of 700c tires available to do most anything you want, but each 700c is different, my Nishiki tops out at about a 700x25c size tire, but there are 700x38c+ sized tires out there if you have the frame to accept them, but I'm also not going to say that building a 26" is a bad idea, most kits out there are built for a 26" MTB frame, and I won't say there is a good reason you had that recommendation, there probably is.

My experience having recently used a couple 700c bikes, is that I get a huge amount more speed for the same effort with thin 700c tires, and though I haven't experienced an electrified 700c yet, (still waiting for the pre-order of the Kepler Drive later this month) as long as you build as you're describing, it could suit a 700c quite well, keeping things light and more importantly, putting the battery and motor in different locations to balance the load.


That being said, I also agree there are better deals in the for sale selection both new and used.
 
1. I figure the lead acid are just starter batteries. Because it would be my first eBike and all.

2. I'm 220lb and got flats on my bike ( Diamondback insight1 ) repeatedly. Someone hinted that this bike is for lighter folk. I figured this could plain just be the wrong bike for me.
( am i right? )

3. I've had a really hard time finding anything that would work for that 700c bike. It's aluminum from start to finish. And finding a steel fork has not exactly been easy.

4. As for tire width, the rims are a hair over half an inch wide and it looks like 25's are already a stretch on those. I think something with a wider rim would be better to contain the torque, particularly considering that it rains out here pretty often 6 months outta the year.

Okay, if there are better deals out there ( in terms of quality per dollar ), i'll pass this up.
 
Yeah, i'd like to get a geared hub motor rather than a direct drive though. I like the lightness and efficiency of them. That eBike kit is compelling, but i think i shouldn't settle for less than
the best, at least in terms of the motor. ( aren't some geared hub motors 12-15% more efficient? )

i know.. wine taste on a beer budget eh.. :)
 
Hey all,

The motors in the ebay special weren't bafangs but rather GM Mini Hub (the pic anyway, who knows)...

700c bikes are most commonly designed to suit the 165-175lb rider weight (race bikes) range and ride on "well maintained roads". I see people all the time out on these in the 200-300+ lbs weight range, the biggest problem they have pinch flats.

Now take avg rider weight and add 40lb of ebike bits (or more) and were upwards of 300lbs - add to that the simple truth I don't know a single person who realizes they should check their air pressure before each ride, let alone takes the time to check (who isn't a serious racer).. the results are obvious.

Geared motors can run a bit more efficient than a Direct Drive much of the time because they spin up to efficient RPM internally faster and so doing hit their sweet spot. They weigh less to but the downside is lower power handling ability - if you want hill assist, you will be fine ... don't expect to drag race Cars :)

-Mike
 
Yeah, i'm tired of pinch flats. Ready to get something with stupidly wide rims :)
Also, it'd go flat in about 4 hours. lol.

Wish i woulda known that when i forked over for the bike. Oh well, it was only $350. Kind of an entry level road bike.

Yeah, not looking for crazy speed, just hill assist with as much pedaling as possible. I'm in it for the excersize. maybe i'll build a beast though later on.
 
neptronix said:
Yeah, i'm tired of pinch flats. Ready to get something with stupidly wide rims :)
Also, it'd go flat in about 4 hours. lol.

Wish i woulda known that when i forked over for the bike. Oh well, it was only $350. Kind of an entry level road bike.

Yeah, not looking for crazy speed, just hill assist with as much pedaling as possible. I'm in it for the excersize. maybe i'll build a beast though later on.
Click to expand...

I hear ya there! I was filling up my tube on my new 700x25c tire and (yes I used the old one .. I'm cheap .. err poor? :wink: ) a customer outside thought someone had fired a .22!

Good thing I was listening to my Ipod, I didn't think it was that loud ... :roll: :lol:

I don't usually have that problem, but 700c are a pain that way! :evil:

I'd still like to get a beefy 700c frame just the same and get a 700x41c and make a Cyclo-Cross racer/tourer too. :twisted:
 
700c are a pain. I remember having wider rims for my 15 mile non-electric commuter.. changing the innertube in the middle of a long country road SUCKED.. but nothing sucks like a 700c flat. I'm over it! Besides, 26" is generally the standard size for EV stuff. And i'm tired of the lack of options :|

I think you can take a little inefficiency

Anyway i'm off this silly eBay idea. The controller looks like the same as in the eBikekit which is nice, but i'm not convinced that the GM geared motor is worth anything more than $0 considering what i've read.

I think i might wait for the Kepler drive rather than spend serious $$$ on the perfect hub motor. Besides, it sounds cheaper and i've got a serious itch to get into this EV bike stuff O_O
 
I sold my SLA batteriers, For only SGD20.00 for 4 batteries. I bought one Cost SGD35- sgd40 each.. they are very heavy.

myself was curios on what is the SLA batteries for 12v 12hr can give you ... how many watts. okay total my test is
210watts .. From 48v 12hr. however this 210watts can give you a couple of weeks only. After 2months over.. the watts is
only 80watts from 48v 12hr. For short range say 3 or 5km, is okay. if is more then that, you will be riding a electric horse !!
i bought those 4 new batteries (48v 12hr), 2 months ago, i just doing a test. Sla batteries cannot work with 1000watts
motor and controller.

cheers.
kent
 
A geared motor, controller and reasonable lipo pack 12s 5AH would weigh about 12 lbs total added weight and give you approx 10mi of range at 20mph or so.

The cost should be around 500.00 total.

Kepler's drive is a great solution but as of now it would require his drive unit + motor + controller + batteries (I would assume 6S4P to go about 10-12mi no pedaling at 20ish) in the end its going to run approx 250.00 more but it will (or can with lesser pack) weigh less.

The only downside as I see it to Kepler's drive system is traction in light rain or other wet weather... As I ride in all types of weather rain, snow, etc... the traction is a serious thing for me, all the same I'm on Keplers list to pickup on of the first units - Since most of the time weather isn't wet, I think it will be a great supplement to my existing stable of bikes mostly for non suspended 20" folders.

TBPH - I think you would be happy with any of the 3 viable options (geared hub, direct drive or friction/kepler drive).

-Mike
PS: The controller you saw is not like those from ebk - it's not an infineon. Many (most) controller look alike but they are all different (some more different than other).
 
Yeah, a controller is like a brick wall for how much power you can put out, right? that's why everyone's talking about modifying controllers on here, etc.

Not looking for a lot of boost here. I really want a light bike with a little assistance rather than something for commuting or racing against cars.. so 90% pedaling, 10% electric power or so.

The cell_man kit is appealing! i think i'll wait until some other people have them in their hands though, hehe ;). But i am insistent on a geared hub motor due to the low weight and efficiency.

Batteries are still not decided on. Any opinions on using the Turnigy ( hobby city ) 'nano-tech' packs? I don't need a lot of range, so i was thinking 2-4 of those would do, especially considering the low power draw VS a DD hub motor. I like their compact size, plus i don't need a hell of a lot of range either.
 
The HK lipos would be perfect for a very light very small battery for use as "just an occasional assist". The only issue would be the temptation to overdischarge them, since you'd be carrying only 5 ah or less. For a 15 amp controller, you wouldn't need to use really high c rate ones either. 15 c would be plenty, with 45 amps continuous capability. 10s would work great, but 12s would give a voltage halfway between 36 and 48v.
 
Good point. I think more capacity is better because of the human factor :)
Plus, i'd have to roll my own BMS with those, correct? ( kind of a problem since i'm new to all this. )

I'm about to buy a cell_man geared kit. It's a meager 250w/14ah/36v setup. Considering that i was impressed by an eZip 'trailz' ( 24 volt ), this should be fine, lol.

What about a ping 36v 10ah battery? It says it's good for 300w/400w setups on the site. I'm thinking this will be a safe/reliable combo, plus the BMS and charger is standard. 8lb is nice too.
Good idea, bad idea? I hear the cells themselves are ~2c.. the ping batteries are about 10 cells?.. so 20c?

Or should i just go with the 15ah to be safe? ~12lb is a little over what i'm looking for, but if it adds a significant safety margin, it's worth it to me.

Any opinions = helpful. I was thinking of going with DeWalts, but since the BMS/charger seems to suck i think i'll pass.
 
A 10 ah ping battery would be good for 2c, but for continuous use AND, getting the advertised number of cycles 1c average is better. 36v times 10 amps = 360 watts, so a 10 ah ping should be ok.

But it won't be ok next year, when you want a faster, more powerfull motor. If you get a 15 ah, you could go as big as a 20 amp controller later. You could of course, buy another ping later, and connect them paralell to have a bigger battery when you need it. A bigger battery now would give you more range, and a more reliable battery now, so get a 15 ah now if the money is not a big problem.
 
The ability to run more amperage down the line is a plus, i think 20amp on the cell_man motor sounds safe if i get the upgrade bug.
The extra 5Ah is not a lot more and only 4lb. I'm trying to keep the weight of the bike down so that it's still good for pedaling, but an extra ~$90 for another 5ah is a fabulous deal.

I think i'll go with that battery. It seems like the best noob battery thus far.
 
Now from the start buy a old steel bike como. 10 - 15 years old for 70.00 to 100.00 used these were 400 to 600.00 bikes with good bearing look at the componances stx, Lx ect. And keep the alum. for a road bike. 26in. is best for 220 plus club. I remind you, it will be plus and who wants a lead sled.
 
I've got a chromoly frame Trek 930, about 27lbs. stock. I think it's just right, weight/toughness wise :)
 
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