First bike, need lots of advice

[flyingpants]

Hi there, this is my first post, although I've read dozens of threads already. I'm obsessed with electric bikes so I think I will fit right in here. I think about them day and night, although I've never ridden one before. My friend recently bought a 72V 20Ah Daymak scooter for $1599 ($1960 total) that will do 75km. I test-rode it, the acceleration is scary fast - and that's a 230lbs bike. So I've decided it's time to pull the trigger.

I used to ride this DeVinci Milano. I could easily maintain 25km/h on flat ground with this bike, while barely touching the pedals. The frame broke and it's gone now.

Here's the view from my house. I live on a steep hill. I'm also at the bottom of the Niagara Escarpment in Hamilton, ON, so I need to be able to shoot up the steep incline at reaosnable speed every day without making my ebike sad.

The Short-term Goal

The short-term goal is just to add a basic conversion kit to my existing bike. Money is tight right now. This is what I came up with so far:

http://i.imgur.com/MOtWhCL.jpg
Thoughts?

The Ultimate Goal
My ultimate goal is to build a bike that will go from Hamilton to Toronto and back with no pedaling (70km each way), able to climb fairly steep hills super comfortable, aerodynamic, and waterproof. Here are some of the requirements:

-140km range (no pedalling), low Wh/km
-LiFePo4
-Needs to fit and support me, I'm 6'2 240lbs
-Most likely a LWB recumbent like a Toureasy, I have back problems
-Needs to be able to climb steep hills such the Jolley cut, and James St. access in Hamilton, every single day with no problems
-Considering a mid-drive motor, possibly with an additional small secondary hub motor
-Needs to be rideable in almost all weather conditions

 

[MadRhino]

My friend recently bought a 72V 20Ah Daymak scooter for $1599 ($1960 total) that will do 75km. I test-rode it, the acceleration is scary fast

You'd probably die of a heart attack with straight white hair and eyeballs out, if you test ride one of my bikes.

 

[d8veh]

That's a lot of torque to put through the front wheel. I think you'd be better with a rear wheel motor.

You should get the upgraded BMS 30 to 60 amps because the controller can be as high as 32 amps, depending which one you get.

Additionally, you should get a pair of their torque arms, and if you want to keep your existing brake levers, a pair of their hidden wire brake sensors. The sensors are essential if you get a bike with integrated levers/gear-changers.

 

[dogman dan]

That looks to me like a lot more hill that a little gearmotor can handle.

Good thing you don't want much. :wink:

Since you mention the goal of no pedaling, I would say leave out all gearmotors, in favor of direct drive motors that can handle more watts, and shed excess heat better than planetary gearmotors. Or a through the gears motor allows shifting down to get up that hill crawling in low gear. Fortunately it's not miles and miles long.

Since you want a bent, I would say head for something with a 20" rear wheel, which will handle hills better.

As for your range, it's possible, but it will take a lot of expensive battery. 1 ah per mile, for 36v batteries, traveling 20-25 mph is one rule of thumb for normal bikes. Carrying that much battery on a regular bike is extremely hard to do. 48v 15 ah is about the max size that carries nice on bikes, but 48v 20 ah is possible.

Switch to a tadpole trike recumbent, and a lot more can be carried easier.

My personal best, is 39 miles from a 48v 15 ah. Achieved by traveling 13 mph. On a regular bike though, not a bent. The faster you go, the worse your range gets. By 30 mph, you can forget going very far. At 30 mph, I get more like 18 miles from the same battery.

Once you settle on what bike you will be using, and what you are willing to spend, we can get more specific about how you could do it. I can say now though, that a little bafang and a tiny battery won't do. Getting up that hill will require one thing, but going long distances might be better with another. I already see a big need for two bikes. But some can be built that do good enough at both.

Mid drive + hub motor is not that bad an idea. But I'd still not recommend that bafang to get up hills that steep. Maybe a GNG kit, plus a bigger hubmotor though. You can do mid drive and a rear hubmotor.

 

[Drunkskunk]

Hills are going to be a killer. That little motor isn't going to live long trying to haul someone your size up those hills. A Crystalyte HS3540 in a 20" wheel would do it.

As for range, on flat ground, you need a battery sized at 36 watts per mile at 20mph. That battery you chose has 432 watts (48v X 9ah =432 watts). that works out to a range of roughly 20km. Add hills or more speed, and that will drop considerably. So considering your need for 140km range, you would need to find a way to strap 7 of those batteries to a bike frame.

 

[d8veh]

The 48v 500w 201 rpm BPM with a 30 amp controller will drag you up that hill OK. It's a superb climber. I'm not to sure why the others are saying it wouldn't. I'm 100kg and I run mine at 36v. It gets me up a 30% grade with a bit of pedalling, and mine's a code 13, which isn't as efficient as the one you chose. Perhaps they can clarify why they say that. Be aware though that its top speed will only be 17mph on a flat road.

 

[dogman dan]

The slow motor would do better than the fast version. I totally agree with that.

Fortunately, if that's the entire hill in the picture, it's very short. So it should not overheat before you get to the top. I just couldn't say if it could climb it at all. Looks even steeper than 30% to me.

But I'm fairly sure that a larger motor given the same volts and amps would climb it better, especially if it's also a slow rpm motor.

I'm not very comfy recommending 1500w into the smaller gearmotors, but I know others have done it with the larger ones, like bmc or mac. Am I just confused and misinformed? How big is the BPM. is it similar to the mac?

 

[d8veh]

Dogman, I think you and the others were getting the BPM confused with the smaller Bafang SWX motors. It's a large geared motor like the MAC. It can go to 2KW for short periods - maybe even higher. I've run one at 64v and 30amps.

 

[dogman dan]

Thank you for the dope slap. I need them from time to time.

201 BPM should work as good as the other stuff I suggested. The hill is short enough to flog hell out of that motor without killing it. I just misunderstood and thought it was the small motor.

I try, but it's hard to keep all the info on all the motors available straight in what's left of my brain. I have some experience with tiny gearmotors, and lots of experience with dd hubmotors.

Where the OP lives, he won't have the climate problem I have. Here in the southwest deserts, gearmotors cool too slow during the summer to be good for me.

So go for it, and give it at least 48v 30 amps. That's 1500w. Cruising at 25 mph on the flat though, you will only use about 800w, and that won't damage the motor.

 

[flyingpants]

So go for it, and give it at least 48v 30 amps. That's 1500w. Cruising at 25 mph on the flat though, you will only use about 800w, and that won't damage the motor.

The motor is rated at 500W. Could you quickly explain how this works? I am guessing the motor just draws more current under a high load.

Using a bicycle power calculator, I got a figure of 1900 watts for a 25% grade at 10mph.

Fortunately, if that's the entire hill in the picture, it's very short. So it should not overheat before you get to the top. I just couldn't say if it could climb it at all. Looks even steeper than 30% to me.

I live at the bottom of a ~300ft escarpment which divides two halves of the city of Hamilton. This means I need to be able to get up and down every day, multiple times a day without worrying about the motor burning out. The main function of the electric motor will be to tackle these slopes. All I want is 6-10mph here.

According to http://www.electricbikerange.info/ and Google Maps, the mountain accesses by my house are roughly 6% (80m/1400m) and 7% (66m/900m) so that's really not too bad. The hill to my house is about 12% (14m/120m). So I am guessing I will be OK.

 

[flyingpants]

Hills are going to be a killer. That little motor isn't going to live long trying to haul someone your size up those hills. A Crystalyte HS3540 in a 20" wheel would do it.

I don't believe that Crystalyte is street-legal in Ontario.

As for range, on flat ground, you need a battery sized at 36 watts per mile at 20mph. That battery you chose has 432 watts (48v X 9ah =432 watts). that works out to a range of roughly 20km. Add hills or more speed, and that will drop considerably. So considering your need for 140km range, you would need to find a way to strap 7 of those batteries to a bike frame.

Where did you get 36 watts per mile? I have read as low as 10 watts per mile, I'm a bit heavy but that shouldn't increase my power consumption by 3x. My friend consistently gets 53 miles from 72v20Ah, only 27Wh/mile and that's with SLAs, 365lbs including him and the bike.

 

[dnmun]

if you get 10W/mile you need to do a thread about it then.

you need to plan for opportunity charging so you can get the mileage you expect. toureasy is a good choice if you can do that but you wanna have the motor on the rear wheel imo. maybe hang the batteries underneath.

 

[d8veh]

The motor is rated at 500W. Could you quickly explain how this works? I am guessing the motor just draws more current under a high load.

It means that you can run at 500w all day and it won't overheat. It can go to 2kw or more but not for a long time. That hill is not long enough to raise the temperature significantly.

The motor will draw about as much as you give it. It's the controller that limits the current. I ran one at 40 amps and it didn't complain.

 

[Drunkskunk]

I don't believe that Crystalyte is street-legal in Ontario.

Possably not, although there is a statute in the law that might make any kit illegal in Ontario:
"For use in the Province of Ontario, a power-assisted bicycle, or e-bike, is a bicycle that: ....bears a label that is permanently affixed by the manufacturer and appears in a conspicuous location stating, in both official languages, that the vehicle is a power-assisted bicycle as defined federally" (Source: http://www.mto.gov.on.ca/english/dandv/vehicle/emerging/e-bike-faq.shtml)
A kit won't have that label.

I think its more important to meet the spirit of the law in a case like this. The police are unlikely to give you trouble unless you give them reason to. As for the Crystalyte, I've seen no official watt rating from Crystalyte. If you operate it as a 500w or less motor, there is no grounds to challenge that it is anything except a 500w or less motor.

Where did you get 36 watts per mile? I have read as low as 10 watts per mile, I'm a bit heavy but that shouldn't increase my power consumption by 3x. My friend consistently gets 53 miles from 72v20Ah, only 27Wh/mile and that's with SLAs, 365lbs including him and the bike.

10w/mi average at 20 MPH might be possible in a streamlined velo going down hill. Anyone who says they can average it on a normal ebike without pedaling has also caught fish bigger than the boat, but it got away, once saw bigfoot come right up to the window, and once won the lottery, but lost the ticket. Very doubtful.
25-30wh/mi is pretty normal at 20mph on flat ground. But you need a battery bigger than that to accommodate natural degradation of the battery over time, hills/headwinds/other factors that come up, and also retain a reserve, as it is bad to fully drain a battery very often. Thus, 36/wh per mile gives you an estimation of the battery size you will need to account for all of these factors.

 

[wesnewell]

Welcome to ES****Do this before your first post or now (it's retroactive)*****
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 and you will waste your time and others. Thank you.
http://www.goldenmotor.ca/categories/E%252dBike-Kit/26-Inch/Rear/

 

[torker]

If I went with a rear motor on a Toureasy I would use a magicpie with the alloy spoked wheel. Op is a big guy and a Toureasy will be way heavy back . I hope this makes sense. Plus the MP alloy is 20 inch good for torque

The good is there is a ton of battery space on the lower tube

 

[dogman dan]

It's not hard to get up 12% grades reliably. You just need a slower winding motor that can periodically handle 1200-1500w. You will slow to less than 10 mph on that hill to your house, but a slower winding motor will handle it fine for the short duration of that climb.

Legal stuff is your own problem, but one nice thing about the slowest windings is that you don't stick out like a scofflaw on a bike with a 20 mph top speed. Ride 35 mph and you do.

Any of the motors we previously talked about will work for the ride. They won't be fazed much by any of the hills that are less than 10%. Even in 26" wheels you will be fine.

That photo just looked steeper than 15% to me.

 

[e-beach]

You could also call Grin Tech, at (604) 569-0902. Maybe they can help you out. They are Canadian after all....

Also, as WesNewell suggested...

 

[LockH]

Hi. Toronto guy here. Once rode a commercial ebike from Toronto to Hamilton (took the train back) and got lost around the harbour and chucked the bike in the trunk of a taxi to climb the escarpment. Had "run dry" the battery by that point anyway.

One of these bikes as I recall:
http://www.amegoev.com/amego-bold-electric-bicycle-e-scooters-0311-1030.html

... so "only" a 36V/12ah Lithium-flavour pack pushing a 500W-rated rear-drive motor.

And to get to Hamilton along the lakeshore all pretty flat. And me a pretty scrawny guy about 150lbs. With lots of pedaling thrown in.

So, your parameters include *round-trip* Hamilton-Toronto and back??? I'd probably go w/a split pack that I don't need to use both batteries every day. (About 1/2 "weight"/mass requiring less energy to accelerate and move.)

And NO pedaling??? Lots of reasons to pedal, including warmth, exercise and shaving peak outputs at startups or up hills.

Other denisons of ES far more techy than I. So can't tap about your tech needs really, but am curious about what may seem to some as "impossible" specs? And yeah, currently looking to convert recumbent trike. (Think comfy seat w/backrest and much more "aero".)

In Canada we have Lord Justin of ebikes.ca of course, but locally for conversions Golden Motors Canada a savvy/go-to guy.

G'Luck

EDIT: BTW, "cut my ebike teeth" riding all over Toronto on a "tiny" stand up kick bike w/2x 12 volt 10Ah lead batteries, w/lots of "up hills" from lake level (Toronto islands) to Downsview and Sheppard Ave. in east end out near "new" zoo.