New guy saying hi!

[Groundthinking]

Hi guys my name is Richie and I'm new here. Sorry if I am breaking protocol by asking questions in my first post, if so I apologise in advance.
I have been researching Ebikes for the past year and a bit and have decided to take the plunge!
I am going to be building up a modest commuter bike based on the Trek 7.0 platform. I found this bike in a council clean up and have since been fixing it up as its derailleurs, cables and brakes were completely seized.
I have some what of an idea of what I want but with your help I know I can make my dream bike. By the way I have no experience with electrics so I want to make this as painless/reliable as possible whilst still being able to choose what I want...ie. geared, but with generous power

Heres what I think I want to do:

AIM: I want a 20km to 30km range and the ability to cruise at 40kmh with good pedalling, I have no problem with peddling with the kit, what I am looking for is for the kit to help me get up hills at 30-40km/h which is 20-25mph. I don't think I want more than this as I'm riding city streets.

- Cellman Mac Kit 500w with 8t, 9fet (this is recommended on the website but maybe 10t with 6fet would be adequate?)
- ping battery 36v 10ah or 48v 10ah (looking for reliability here hence Lifep04 and not sure if the 48v will over stress the mac kit and its controller? will take reliability over speed)

I am thinking of mounting the motor on the front as I like to peddle hard as well and dont want it to interfere with that at all. Once again completely baseless logic there just assuming it will feel strange?

I also know that cellman does a 50v 10ah lipo battery i dont know what the thoughts are between this and the ping with the Mac motor but am totally open to suggestion.

I think that is all my questions atm. Ill post the bike build up on the forum when I get started with your help. BTW do you need a cycle analyst? I'm confused or will the kit still work reliably without it on its own?

haha sorry if this was painful guys I'm just a noob who has been bitten by the electric bug

 

[Ykick]

What continent/country are you located?

 

[dogman dan]

A 10 ah ping will struggle to power a bigger motor and controller, so I keep saying get the 15 ah. 20 is too big to carry well, but 15 ah is tolerable. Carry the battery inside the front triangle of the bike if possible.

In general, a rear motor works better for most. It won't change your pedaling, and be quite compatible with bikes with 7 speeds. Front hubs are more for bikes that can't take a rear, like delta trikes, or bikes without suspension forks. Front hub can be nice in some ways, but many hate that much weight on the front wheel when they come to curbs or other obstacles.

You should get your 40 kph, but it will not be quite that fast up steep hills. You should see 25kph up the hills.

 

[wesnewell]

Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations. Thank you.

 

[John in CR]

Wenewell, how's that new job with the NSA workin out for ya? It's certainly wearing on the rest of us. :wink:

 

[HAROX]

Wenewell, how's that new job with the NSA workin out for ya? It's certainly wearing on the rest of us. :wink:

for sure. :wink:
and yea, Groundthinking, I do need a cycleanalyst. do you have an extra by chance? Just kidding. not

 

[wesnewell]

Wenewell, how's that new job with the NSA workin out for ya? It's certainly wearing on the rest of us. :wink:

If I could just get the people that run this forum to make entering a location mandatory on sign up it would make my job a lot easier.

 

[el_walto]

MAC 10T at 48v will do what you are looking for.

Get the 6 or 9fet with 3077. 4110 fets will just run hotter and are only needed for 72v setup. I have the 12fet and it has crazy\twitchy acceleration\hill climbing, probably a little hard on the motor.

If you are going front wheel, you need solid forks that are steel, and use the 6 fet controller for this.

Consider a battery from the same supplier for simplicity reasons. Make sure you have a large enough triangle on your frame: http://em3ev.com/store/index.php?route=product/product&path=35&product_id=123

 

[Groundthinking]

Hi guys thanks for replying.

I am located in Sydney, NSW, Australia.
Bike has a 7 speed cog at the back. The frame is 58.5cm.

So far suggestions have been:

- 48v battery with MAC 10t with either 6 or 9 fet. Cheers el walto and would the 10.25 amp version be adequate (http://em3ev.com/store/index.php?route=product/product&path=35&product_id=128)? Also whilst I like the triangle frame pack for practicality reasons, it is too expensive at that price, does anyone know if cellman does the other battery versions in that bag?
- 15ah battery Ping battery. Thanks Dogman and would you recommend the 36v or 48v version? I think 25km/h up hills is acceptable performance for me.

I will take your suggestions on board regarding the rear hub set up with battery in the frame.

So I have 2 major questions regarding batteries.

1) Considering cellman says you get 30% higher top speed and more torque using 48v vs 36v holding all other things equal. Would a 36v system with 8t and 9 fet produce the same performance as a 48v system with 10t and 6fet? Which one would be more reliable?

2) I would like to buy everything including batteries from cellman but am a little wary of the Lipo battery configurations in regards to reliability/longevity and complications/risks with charging. If I were to go with a mac motor 10t, 6fet, which battery would better suit my needs a 50v 10ah lipo or a 48v 10a LifeP04 considering I want reliability?

 

[Samd]

Heya fella from down the south,
are the wheels 26" or 29er/700c wheels?

Cheers.

 

[Groundthinking]

Hey samd, they are 700c. I should have mentioned this earlier as this changes the gearing significantly doesn't it?

 

[Samd]

Having both 26" and 29er wheels I can confirm it does change things (funnily enough by a ratio of 26/29 mate).

So you'll get about 10 more top speed and ten percent less acceleration off the mark. Not much but if you are talking about hills, which voltage to run and which wind of motor to select you might select for a Mac/BPM/Ezee sized gearmotor then it's a factor.

Are the front forks steel at the dropout? A fridge magnet or similar will quickly confirm...

Cheers.

 

[Groundthinking]

The bike isn't here with me atm, but from memory I am certain it is high tensile steel...here is a link to a more current version, but nearly every component on mine seems to be the same as this one...http://www.trekbikes.com/int/en/bikes/town/fitness/fx/7_0_fx/#/int/en/model/details?url=int/en/bikes/town/fitness/fx/7_0_fx

I have the 22.5inch frame version. I am also now not adverse to putting the motor in the rear wheel if it fits with the cassette and disc brakes that I plan on running on it.

 

[Samd]

Should be a ripper. There are local options too for gearmotors such as ES user BenMoore in Melb for BPM motors, and Gloworm in Sydney make great Ezee wheelsets. I have a disused front I just pm'd you about but will happily keep it in my shed!

Some local lipo battery makers too.

Of course the Mac is still a nice choice. I think you'll love that bike under some good geared power.

 

[Groundthinking]

Funny you mention glowworm i drove past them yesterday will check them out. Which local Lipo manufacturers do you recommend?

So the Ezee is a front hub geared motor, what controller battery go well with this motor? On another website it says its got a 20A current limit

 

[Nanoha]

Hi Groundthinking.
The ezee motor is almost identical to the BMC, MAC and Bafang BPM.
I would put it a lot closer to the BMC than the others in terms of build quality and seals.

If you are going to drop by glow worm then I would just test ride a complete bike to see if it meets your needs.
That way it saves you the hassle of sourcing everything and then wondering if it will all work and for how long.

 

[Samd]

Ezee do both front and rear. You can compare it on the ebike.ca sim to the BPM and maybe the mac too.

I've run my front ezee at 15s63v32a and 10s42v35a in bursts but you'll need really rugged front forks and torque arms. A tight steer tube too. It got silly for traction on 700c28 road tyres though and I swapped it out for a tiny q100 for my flat work commute. The nice part about ezee is the warranty and local supply of gears in the unlikely event you strip one.

I'm running my rear BPM on same wattages but the chinese wheel build and rim that arrived were pretty average.

I run a v1 rear ezee on my wife's cargo bike with two kids in it. You could put a keg of beer up front and it'd still climb over a hummer. I'm running 42v21a in that from a tiny 6fet.

 

[chas58]

Hey samd, they are 700c. I should have mentioned this earlier as this changes the gearing significantly doesn't it?

Maybe. 26" wheels are not 26." In fact a typical 26" mountain bike tire is basically the same circumference as a typical road bike tire.

Its the tires that matter, and that can make a big difference. (obviously a 26x1" tire is different than a 700c x 2" tire)

 

[chas58]

Ah, I see you have the Trek FX. I am tempted to use that as a bike to electrify. It looks like a good basis. The less expensive ones (7.0 to 7.3) tend to have steel front forks. Personally I wouldn’t put anything over 250 watts on the front because a failure there can maim or kill you. But people do it.

1) Considering cellman says you get 30% higher top speed and more torque using 48v vs 36v holding all other things equal. Would a 36v system with 8t and 9 fet produce the same performance as a 48v system with 10t and 6fet? Which one would be more reliable?

2) I would like to buy everything including batteries from cellman but am a little wary of the Lipo battery configurations in regards to reliability/longevity and complications/risks with charging. If I were to go with a mac motor 10t, 6fet, which battery would better suit my needs a 50v 10ah lipo or a 48v 10a LifeP04 considering I want reliability?

#2 Cellman doesn’t cell Lipo, its mostly Li-Ion. No worries there. However, LifePO4 will give you about twice the duty cycles. It is a bit heavier than Li-Ion.

#1: Good question. I’m not sure anyone knows!
Power is watt x amps, so current being the same, the 48v will give more power. But you ask a good question, at the same power level, and assuming the motors are turning the same speed, is there really any difference between 48v and 36v?

If you keep the current the same (assuming the wheel speed is the same), the 36v will have 33% less power and also 33% more range (and also be 33% smaller, lighter, and cheaper). But people like power. I like 36v, but I like providing 50% of the power. Most people eventually want more power and increase the voltage.

 

[Samd]

Personally I wouldn’t put anything over 250 watts on the front because a failure there can maim or kill you. But people do it.

Strongly disagree. The reality is that lots of us here do it.
A decent pair of front steel forks with a TA will happily take 1 kilowatt. And we should be talking the rate of change of torque, driven by amps and the torque and braking characteristics of the motor.

If you want finite data on fork failures there is a brilliant 8 page epic read where Justin destructively tested lots of varied kinds here:
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=14195&hilit=front+fork+test+torque&start=50

The front fork myth is in danger of being propagated across here in the same way as the myth that gear motors strip with more than a kilowatt. You may find a few front failures on here. And just as many rears.