Advise on setup 30m@30mph

NHM

1 mW
Joined
Nov 1, 2014
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14
Preparing for my first ebike build.
My target is to do 30 miles at 30mph. Flat road with max 5 deg hills for max 500 yards.
First advise is mid drive or DD rear hub?
Bike will be a full suspension 29'er with upgraded brakes and wheels.
Will 48v do the job or should I be at 60 or 72v?
Have consulted the simulator, but have a feeling experienced riders can target me better.
Directions to kits would be appreciated. (Not US)
Thanks!

/Neil

PS. No intentions to challenge legislation, so private or legislation free roads only :D
 
http://www.zeromotorcycles.com/motorcycles/
 
It's within the capabilities of the cheap direct-drive hubmotors.

With 29" wheels you should hit 30mph easily with 48V. It will work the motor harder than a 26" wheel, though, so you need to take that into consideration.

You'll need a battery with a useable capacity of 1000Wh, which is largeish for an ebike.
 
Slow DD hub laced in 24" wheel (eg. Clyte HT)
20s 3p of 5800 mah RC Lipo (Read and learn about safe maintenance of them)
Lyen 12 fet controller set to 30A

You will not have high performance but you will do your target speed and range most of the time (short on windy days), if you build a light weight bike and you are not heavyweight yourself.
 
Generic 48V 1000W ebay kit and 30ah 48V battery pack will do it.
 
Im pretty happy with my MAC10T geared hub at 58v (14S Lipo). Do some reading on DD vs geared hub to make sure you know what you want in a hub.

Generally a A DD can
- take more power as it is larger ( heavier )
- stands out more... bad if you want to stay under the radar.
- has some motor drag if you just want to pedal or freewheel down a hill without power.

A geared hub
- smaller physically ( lighter. )
- power tops out at about 2-3kw.
- more torque for the power
- can freewheel (feels like a normal bike when unpowered)

Anyways, have a read of my build log - Similar setup - 29er (mine is hardtail). I found 17Ah of battery to be able to do 50km (30miles) of commuting (using six 7S 5800mAh zippy lipo packs in 14S3P config) ... with a lot of start and stopping on max power mode.
 
Raged said:
...I found 17Ah of battery to be able to do 50km (30miles) of commuting (using six 7S 5800mAh zippy lipo packs in 14S3P config) ... with a lot of start and stopping on max power mode.
but i guess this is with a lot of pedaling. the TS shoud show up and clarify if he wants to ride the bike like a bicycle or like a motorbike. because doing WOT 35mph for 30mi needs 1500Wh imho. i have 20Ah 24s lifepo4 in my 4kW bike and can do that distance. my 2kw midrive with 20Ah gives me 30km at full power.
 
30 mph is doable with 48v, if you choose a hubmotor with a medium fast winding. Typical of the cheaper ebay kits called 48v 1000w.

Many of the other better quality choices are closer to 27-28mph. ( like a mac 10t) This is plenty dude, don't get hung up on 27mph vs 30. Just focus on getting something that works well for you.

As for what will it take to get 30 miles full throttle? That's just some simple math. We know a 48v 15 ah pack will take you about 18miles WOT. That's around 750 watt hours. And the rate is around 41-42 wh/mi. Since adding a 10% reserve to your size is a good idea, do the math with 45 wh/mi.

30 miles x 45 wh/mi. You need a 1350 wh battery. About 48v 28 ah.

That's huge, But in some types of cells it could still be under 20 pounds. How to carry it is a problem, but two 13 or 15 ah batteries could be carried in panniers, one on each side. Or you could carry one in a handlebar bag or box, the other on a rear rack. Ideally, one would fit in the frame triangle.
 
I recently put one of the 1000 watt 48 volt ebay motors on a mountain bike. I have 15ah at 48 volts. My other build is a recumbent trike with an RC motor on it and I have been surprised to find that it is more efficient than the hub motor. It is about a 2500 watt motor with serious acceleration and about 30 mph top speed. It has 20ah @ 48 volts I think it would do 30 miles but likely no reserve at all. I have put 20 miles on it on multiple occasions. It is also far more comfortable than the bike and could more easily carry more battery. It is a much more difficult build though where the hub motor is almost turnkey.
 
The efficiency different is because of wind drag difference between the recumbent trike and the mountain bike. The same setup will go faster and farther on a recumbent than it will on a mountain bike. A 48V 1000W generic DD system using a 20ah battery will top out around 30mph for ~20 miles. The same system on a recumbent will top out around 35mph and go ~40 miles on a charge.
 
I pedal a bit (ghost pedal a lot ) but I think its more to do with the freewheel. My ride is rolling hills, so when I'm going down hill, I don't need to throttle... and when I'm near the busy area's in the city, I can just roll with the other riders... e.g. feather the throttle and freewheel roll with them.
 
I am with dogman why is 30mph so important ?? I have a Mac10 t on a 26in wh full suspense 30amp controller I run a HPC 52v 12.5 AH battery I weight in @ 6ft 255 LBs on the flat I getting around 22 mi top speed 28 , the 30mi is that to and from work?? if that's the case its 15 mi oneway just take your charger to work pug in your bike @work . The faster wind Mac s might work better for you then a 10 t you can get just the hub from Paul at EMV3 for around $250 and it is a quality hub motor
 
These are great experiences. Thanks!
Indeed different feedback from riders towards the calcucations. I was at a 72V mid drive cranking out 3-6kW. Most posts from experienced riders are at the 1kW 48V DD motor and serious rack of batteries.
'I set my target at 30 miles doing 30mph, as this is a reference towards my timetrial route doing 25 mph at 20 miles. My aim is to build a ebike that i can extract power consumption and road data towards the pure leg powered ride. (I believe the cycle analyst can do that for me with a data logger.)
As I will need to slow down to 20mph as part of my ride is rural (and have no intentions of provoking legislation) this will cut down on the battery rack.
Curius that no posts mid drive units like the cyclone pack.
Will look more into EMV3´s packs.
Thanks. Pic will be posted of my ride eventually.
/Neil
 
On my second build right now - check my Ross build thread below. After much consideration, including all you're going through now, went with the MAC 10T from EM3ev and a 48V battery pack. FYI, cell_man won't warranty the motor with any higher voltage battery as that would stress the motor too much. I'm putting on a 4 * 8S1P A123 AMP20 battery pack yielding 40ah @48V. I like to stay in the safe 80%<SOC<20% capacity range for battery longevity, so effectively about 25ah. And yea, expecting 25 miles @25mph, the longest ride I'll be taking, which will do me fine. Motor on its way so all theoretical until the wheel is on and I'm spinning asphalt.
 
i have built my own mid drive, but this is a totally different story. it can do 30mi/55km/h but it can't do 30mi with 1000Wh. maybe going flat, but i'm mountainbiking with it. as you said it would be your FIRST bike we were suggestion a hub motor as this is what most of us start with. you're up and running much faster then with a middrive.
if you want to go the mid drive route: there is LightningRod's mid drive, EGO kit, and many others more.
 
Most people suggest a hub motor because the chances of f*ck up are less and you don't need any special tools as long as you get a complete kit.

It's literally :
- screw on the side panels of the motor. (if you bought an already laced kit)
- Bolt brake disc to hub.
- Strap on the freewheel. (twists on).
- Align wheel into frame with the right washer sizes and tighten it. This takes a while... it's not hard but time consuming. Might need to file down the dropouts a bit.
- put on a torque arm.
- plug everything in to the controller (all plugs are the right sizes and can't be mixed up). All you need is the plugs to motor, power, 3speed switch, throttle.
- mount controller (my first version was just cable tie to the seat post).
- mount throttle.
- plug battery in and make sure it won't fall off the bike.
- check spoke tension.
- Go.

Bonus points for trying to make it stealth to avoid the po-po
 
NHM said:
...
Curius that no posts mid drive units like the cyclone pack.
Will look more into EMV3´s packs.
Thanks. Pic will be posted of my ride eventually.
/Neil
Well, you are riding mostly on the flat and a hub motor is very simple and efficient. Mid drives do require much more building and tuning, and at the end they also require much more maintenance. A low power mid drive can be reliable, and for someone willing to add some fair leg power, can give a long range with a relatively small battery. Most suggestions that were given are targetting your required speed and range to be done on motor power only.
 
I have about the same wishlist. My goal is to make a commuter for a 40 km round trip (20 km one way) to work and it will be run for about 10 000 km / year. Temperature +30 -> -15 C, rain, snow and shine... It is not clear if I'll be able to charge at work or not and I also wish to have extra capacity for weekends and battery longlivery. I am quite light, 70 kg and I don't mind the large battery. I've come to the conclusion that a BMC V4T from Ilia run at 72 Volts in a 28" wheel and dual Ping LiFePO4 36V 20 Ah will do the job limited to somewhat 1200W and 50 km/h to be nice on the cluch and gears. The higher voltage compared to a 48V setup makes 3-4 % units higher efficiency at max speed and about 10 % units at speeds below 30 km/h. If I charge at work I'll have 2.5x capacity if going full throttle all way and the battery will last more then ten years and still get me to work at full speed. The commute is very flat, 14 km along a 70 km/h low traffic road and 6 km at bike paths (where i have to slow down...) in the two cities. Will start the build in the middle of januari I hope.
 
If your commute is flat, 30-MPH can be easily done with 48V, but if more volts will fit your budget, you will appreciate that after you have read more. A longtail cargobike would be my first choice as a serious commuter (edgerunner, Mundo, ODK, etc), they can easily hold a largish 20-Ah battery.

For a 30-mile commute, I would add a modest front fairing to reduce drag. It would not help much at 20-MPH, but for 30-MPH and 30 miles, you need all the help you can get. All the longtails I mentioned allow a large chainring (52T-60T) so you can pedal along with the motor. being able to add pedaling should help your battery range quite e bit...
 
Might be worth looking at recumbents with a fairing, if you really want to go 30 mph efficiently.

I have a huge longtail, and at times it's been quite capable of 32 mph depending on the motor I have on it. But the wind drag of the huge panniers I put on it make anything above 20 mph use crazy amounts of power. But for a short trip, very nice to haul ass to the grocery.

That's the real tradeoff, the wind drag of 30 mph for a long trip just means you have to carry a gigantic battery to have long range, which makes you need a longtail, or a frame designed with a large battery tray.

Dropping your speeds to 25-27 mph gains you much. Less battery needed, a 48v 20 ah likely plenty for 30 miles. That's a battery that fits in a normal bikes frame bag.

And one thing I've noticed since the 70's when I had a 30 mph moped. Cars will behave around you like you are a bike going 15-20 mph. At 30 mph, they will try to kill you all day turning in front of you.

It's a bit like, ride bike speed, or be a motorcycle. In between is dangerous.
 
I have been riding a bike like this for five years now. It is a Trek 820 with a 48v 20a lifepo4 battery measuring 13x5.5x5.5 inches. I have done an average of 30 mi at 30 mph many times. In hilly areas this usually means speeds between 23 and 45 mph. At these speeds though you had better have some good tires. As cheep as they look the Bontrager tires that came with the bike may not last 10000 miles as I am on my third set but they are tough as nails and have carried me reliably over a lot of tough terrain. To get the miles out it is just as important to have the right tire pressure. I have done over 70 miles at an average speed of 15 mph which you will find is a more normal speed on an ebike. My bike is a front hub drive jz36v500w from e-bikekit and has never been more then warm to the touch. The reason that I went with this config is because of ease of maintenance and balancing for street or back woods = no mountains just hills.
 
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