Need help deciding on which kit to buy

jordogs

10 µW
Joined
Dec 9, 2013
Messages
5
Location
ACT, Australia
Hi all,

I'm looking for a kit for my hardtail mountain bike, image attached. I've also attached the gradient profile from map my ride home. The distance of my commute is about 12 km (7.5 miles) one way, and I have no opportunity to charge it at my destination, so I need a range of at least 25 km (~15.5 miles). I plan to pedal during acceleration and during the hills, however at the end of long days I am so tired I really don't want to have to pedal hard. My goal is a cruising speed of 30 km/h (20mph), regardless of gradient, with a total load of around 135kg, including me, my cargo (in panniers) and the bike (I'm 6ft tall, 90kg/200lb).

From what I can gather I'm thinking I should use a 25 amp controller, with a 36v 15 amp hour battery. At the moment I'm thinking of ordering a PING battery, but if someone can suggest something cheaper or better at a similar cost that would be appreciated. As for the motor itself, other than being a rear hub motor I'm not sure which one I should get, and your recommendations here would be greatly appreciated. The bike frame is aluminium so I also feel I should chuck a torque arm on the rear, and I'd also like recommendations for this.

In case it doesn't show up in my profile, I'm located in ACT, Australia.

My budget for this build is $1000 for the battery and motor kit.
Thanks for your suggestions, Jordan.
 

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Hiya Jordan,

Guess I'm the 1st to chime in here?

Ive been very happy with my 500w direct drive motor kit and with my dealings with Cellman at EM3ev .

http://em3ev.com/store/index.php?route=product/product&path=36&product_id=54

I used the least expensive shipping option (SAL I think it was called) and my kit arrived in about 3 weeks if I recall (to USA), but even Cellman commented that that was pretty fast. I have no idea if shipping is faster or slower to Australia tho.

I'm not seeing a listing for a "rear" Torque Arm at the EM3 site. Not sure why.I thought he used to sell them. I buy mine from EBikeCA and this page on their site has some good info on torque arms in general.

http://www.ebikes.ca/torque_arms/

Even if you are building a rear drive Ebike with a strong steel frame at lower power levels that may not *need* a torque arm I have found that if you are using regenerative braking without one the reverse forces involved will work your axle nut loose over time so I just use torque arms on every build now.

I haven't personally had any experience w/ a ping battery so i can't be any help there. A friend picked up 36v 15ah lifepo4 pack from Vpower and he seems happy with it. The 2C (30amp) rating of this pack will be enough to power a 25 amp controller with a bit of room to spare. Vpower has auctions up on Ebay but their direct website is here if you want to check it out: VpowerHK

http://www.vpower.hk/product.php?id=20

the price seems pretty reasonable if you opt for the free surface shipping option but, again, I have no idea about shipping to your location. My friend had to wait about 8 weeks for delivery to Washington State USA after being quoted 7 to 9 weeks, so at least they deliver, in his experience, within the quoted time frame.

I'm running my 500w EM3 direct drive motor at 48v / 40 amps and i was looking for a specific configuration to fit my bike frame so I built a 16s 12AH headway pack with cells and a BMS from EVassemble. ( http://www.evassemble.com/index.php?mai ). I have been very happy with that battery pack for the last 3 years or so and no complaints with my dealing with them as well but if you are sticking to 25 Amps the 10C headway cells might be a bit overkill.

Any ways, there is my 2 cents.

DC
 
http://www.ebay.com.au/itm/Electric-Bicycle-E-Bike-Conversion-Kit-Brushless-Motor48V-1000W-Rear-Wheel-Rack-/150956506830
10ah of 20C 12s lipo will do the round trip easy at 20mph. That's 4 of these from AU warehouse.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15376
Would recommend the thunder 1220 charger for fast easy balance charging.
http://www.hobbypartz.com/75p-1220-charger.html?gclid=CNa3z9_N57ICFayPPAod10MAPw
And this to monitor battery voltage/capacity.
http://www.ebay.com/itm/Waterproof-Digital-Voltmeter-DC-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-/170846310527
Total will be about $600 including a PSU for the charger. I've got over 10,000 miles on basically the same kit.
 
I'll go along with DC for Cell_man EM#EV.

The DDs are good and the battery he now has a 36v 16AH is only $500 but you need to buy a charger which are about $75. $235 for the DD kit plus shipping is about what you bugeted for. I was looking at the bottom rt frame mount battery. links

As for the hub kit I would get the middle one 335 rpm.
But this is up to you with big hills you might want the slow one for more torque.

Dan
 
He doesn't have a battery now.
 
I'm more inclined toward wesnewell's suggestion due to the lower price. Is there any distinct advantage to going with the more expensive battery from cell_man? I could make up a 15AH battery with 6 of those lipo batteries wesnewell linked for $200 less than the em3ev, couldn't I? Although apparently 10 AH will be plenty? I'd also prefer to buy in Australia due to the faster shipping, and wesnewell's option caters to that. That said the em3ev option does have a nice battery case, and I know what motor I'm buying better than with the eBay kit. I'm a little divided on what to do.
 
good set up Wesnewell. with the added bonus of being Australian sourced. Kudos.

I think Dand214 was saying the battery Battery pack Cellman has now is a decent option. And within the price range.

DC
 
"Advantage" is hard to quantify completely. Lifepo4 or LiNiMnCoO2 chemistry will be more plug and play, Lipo will give the most bang for the buck in terms of amps/watts per weight and dollar but will require a bit more hands on maintenance. it just depends on what you value the most.

DC
 
Just to give you an alternative point of view: All that stuff is a bit dated now. You can can get higher spec stuff now, which may even cost a lot less.

There's cassette motors now, that are not only very high quality and reliability, but they allow you to use a cassette free-hub on the back, which offers much better gearing options. A standard free-wheel set for that DD motor has 14T top gear, which is too low for comfortable pedalling at 20 mph. You can get a DNP free-wheel with 11T top gear, but they're not the best, and you might have width problems if you go above 7 speed (if you can get one).

There's controllers with nice LCD displays,where you can set the level of pedal assistance. They also have all the features of a cycle computer, plus, they show your battery voltage. These controllers come in sine-wave versions for quieter running and higher efficiency.

If you have nice brake levers, you'll have to chuck them and use the kit's ebrakes, which might well have the wrong leverage for your calipers. You can get in-line brake sensors, so that you don't have to change anything.

For 20 to 22mph, I always recommend this kit from BMSBattery, although you can get it elsewhere, which gives very good hill-climbing, comfortable cruising at 20 mph, top speed about 24mph, range of over 50 miles for a cost of about $850, and weight is only 10.5kg for everything.
Bafang 500w CST motor
36v 20aH shrinktube battery
S12S controller plus LCD display plus speed sensor
Hidden wire brake sensors
Torque arm
Throttle
PAS
Here's a bike with that stuff fitted 24kg total weight:

 
After doing a bit more research, and hearing the advice of others, I've decided 36v may not have the power I need/want, so I've decided on a 48v system. The battery I'm looking at is the 48V20AH LI-ION SHRINK TUBE EBIKE BATTERY PACK from BMS Battery, anyone on this board have any experience with these batteries? Is the charger they come with sufficient? I'm also looking at the 1000w Mac kit at em3ev, with a 9fet 30 amp controller, and 10t 255rpm motor speed. I realize this may be a bit overkill for commuting, but I wouldn't mind the extra power just in case. Am I missing anything here?
 
Pros and Cons on BMS. Some have had good luck with them and some not.
Prices are good but shipping from THEM is always on the upper end and then some. Put what you think you want in the cart and then see what it costs to ship. be sure you are sitting down when you do!

I can't say much against them, other than they don't have much or any support if there is a problem. they are not sure of what they sell from day to day, that I can vouch for. If you know what others have bought and am sure it's the same take that shot.

Batteries are a gamble from most suppliers. Only a few will stand behid they. I can't say that for them myself.
Ping and Cell_man does.

dann
 
Thanks for your response danm,
Since I'm already planning on getting the motor kit from em3ev I might as well get the battery from them too. I'm looking at the 50V 14.35 Ah samsung pack, will this get me a range of at least 20 miles with the kit I previously mentioned?
 
What are you missing? Just about $500 now. More later when you start having to replace gears and clutches in the motor. Don't get the geared motor for a commuter with only a 2% grade. By the time you pay shipping you'll probably end up over that $1000 budget, and for what? A slower bike that cost a lot more, and is more prone to breaking down. Why do I waste my time. You're going to pay extra for a 9fet controller, when the kit I recommended comes with a 15 fet. That just doesn't make sense to me.
 
Very interesting, I was debating whether to post my own thread or just throw it in here. Im just another newb!!!

Only question I really was searching for was is EM3ev a good company, consensus is yes. Great. I am shy from buying anything offshore, especially from China.
But I see this user "cell man" person sells the MACS, I again am shy from buying online, I did buy a couple cell phone batteries on ebay once, my only non brick and morter online buy.

Next question I had for a tall heavy dude like me (300 lbs.) what MAC should I buy, 12T,10T,8T or 6T, I assume higher torque is better especially for hills.
So my first choice would be a 10T or I could go safer and slower with 12T.

As with everything on any forum I go to I get mixed information. Now I know the gearless Direct Drive motors have resistance, how much I couldnt find out, searched it and couldnt find much to convince me if its a light drag or heavier drag on the Direct Drive.

So, I hear good things about geared hub motors and I am not going to ride hard core, I am just a lazy tall heavy dude that doesnt like to break too much of a sweat going up hills, but I do like speed on the flats and honestly I think 35-40k/m is plenty for me. The hills around my house are slight 2-3% and long 250m-1km, with some steeper short road hills 100m tops. While if I go into the only provincial park within a city in North America "Fish Creek PP" then there are some steep short hills 30-50% + 75m ; every now and then that I'd like to cruise up without getting off. Then I'd probably have to let the motor cool down by not using the motor and pedalling, anyway enough ranting, more questions.

OK next question, batteries.....was thinking Hobby King lipo, I read up on them about their problems, seems good value. Is this a good choice? Seems like a reasonable price for the issues, that Im willing to put up with. What brand of Hobby King batteries and what C rating?
 
I'm a firm believer in buying from a company in your own country if possible. Several reasons behind. A large dealer buys from China in bulk and pays very little per item in shipping charges compared to a single individual that buys 1 kit. If you buy from a company in your country and a problem arises, you will have some legal recourse. Good luck trying to deal with someone in China. You will be supporting someone in your country. There are lots of dealers in Canada. If I were in Canada, I'd probably buy from goldenmotor.ca. I'm only 270lbs and the 901 pro clone I use has worked well for me. If you want more power on the low end and less top speed, then the magic pie might suit you better. And I've bought all my kits through ebay. They were cheaper buying them that way even though they come from a large dealer that has their own website, but sells them higher on their site. I wouldn't buy any geared motor. Just added parts to fail. Pedaling a DD motor has a little drag, but at slower speeds it's hardly noticeable. Besides, you don't have to pedal, because their are no gears or clutches to fail like they have in geared motors. I run my 901 pro clone on 24s lipo and have over 10,000 miles on it. try that with a geared motor and it'll melt pretty quick or tear up the clutch and gears. I've been using RC lipo ever since I switched to lithium batteries almost 3 years ago. Never even had a puffed cell yet. Not a chance in hell will you see me use anything else until it 's as small, packs as much power, is as light, and doesn't cost much more. For a typical ebike, a 20C pack is plenty.
 
As an update to this thread I did end up going with the ebay kit and batteries wesnewell suggested. I chose those batteries because they are coming from a nearby warehouse (relatively speaking) and shipping was much cheaper than getting from overseas. The ebay kit was cheap and if it doesn't suit my needs (though I expect it will) then there is no big loss.
 
jordogs said:
As an update to this thread I did end up going with the ebay kit and batteries wesnewell suggested. I chose those batteries because they are coming from a nearby warehouse (relatively speaking) and shipping was much cheaper than getting from overseas. The ebay kit was cheap and if it doesn't suit my needs (though I expect it will) then there is no big loss.

Hope it works out for you.. You should read the Endless sphere Thread on LiPo failures... some of them are heartbreaking.
 
Those do require extra work, but from what I read they are worth the bang for the buck.
 
Lipo is not for newbes and need a balance and to follow the lipo rules Very closly or else you my have afire that is hard to put out.best to charge in an old baraque. They are not plug and play but a hobby battery not to be taken to work or school.
 
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