Need Help Selecting Bike | Endless Sphere DIY EV Forum

Hi All,

My first post here, and there are so many things going around my head from reading all the great info on here, that i think i should just ask for some advice.

I am thinking of dipping my toe in the electric bike waters for the second time. I have an Urbanmover 36x MTB style off the shelf electric bike at the moment but i think i would like to upgrade to something better. The Urbanmover is fine but the motor is just too weak and it is solely a pedal assist machine.

My thoughts at the moment are this:

I have a 13 mile commute to work (one way) and i need to find a setup that can get me there briskly.

So i was thinking my requirements should be as follows:

- I want 25-30mph top speed and maybe 20mph average (I was thinking a 48v 500w rear wheel setup)
- I will cut down by half on range since this will be half battery weight and i can charge at work (So would 48v 10ah lifepo4 be enough for this range over its life?)
- I do not want lipo ( too difficult for charging etc...)

Do you think a system as above should be enough?

Now the base bikes. I have seen a few and maybe need some help here:

I want a pannier rack that can carry full panniers and battery pack/controller. I want to use Schwalbe Big Apple 26X2.3 to smooth the bumps and give good roll. Maybe a good seat and suspension seatpost to go with this.

This is relatively cheap with a steel frame and front suspension. 7 speed freewheel and v brakes
http://www.amazon.co.uk/Silverfox-T..._1_41?s=sports&ie=UTF8&qid=&sr=1-41



This one has front a rear disks. 7 speed freewheel. Alloy tubing
http://www.ebay.co.uk/itm/VIKING-UR...?pt=UK_Bikes_GL&var=&hash=item7dbd



This one seems good spec for the price. Hydraulic Disks. But is 8 speed? This will be problems for hub motors?
http://www.ebay.co.uk/itm/RALEIGH-A...?pt=UK_Bikes_GL&var=&hash=item7dbc9e90dd



This one is a little more expensive but has the tyres i want on the bike.
http://www.bikes2udirect.com/B.html

Any help in making choices would be much appreciated Though some days you'd make it at that speed with 48v 10 ah, I think you really should go with a 48v 15 ah pingbattery or similar lifepo4. If you are using the lesser c rate cells such as pings, you need the 15 ah to have enough amps to sustain a - watt peak motor. If you went to an A123 pack, then maybe a 12 ah pack would be enough.

It just takes more wh than you think, above 25 mph. About 30-40 wh/mi Plus you really need to not use it all everyday, so even though your max expected use is 520 wh, you want to carry battery about the size of 48v 15 ah.

I kind of like the last bike best. The raliegh is ok, but no rear disk. If it at least has a rear disk mount, you could change that later. The other two , nah. The one thing you really want is a big enough triangle to fit a 48v 15 ah battery. Unless you get a triangle shaped A123 pack, you'll need enough space for a box about 6" x 13" . You won't be as happy if you try to carry the battery in the back. So get a big frame unless you are short. If you are short, get a triangle shaped battery to fit smaller frames. Thank you all for the great replys. Now i find my head is even more confused than when i began

dogman - Thanks for all the good information . It really takes 30-40whrs above 25mph? Wow... i was thinking my max usage would be 20whrs with a bit of pedal assisting. I knew maybe 10ah battery was cutting a bit short over time and i do not want to be left short since is a bit of a leg killing hill just before my work, especially with a 35kg bike with now power

The Raleigh that i linked to there actually has disk front and back (hydraulic). You would recommend disks as a necessity?


So i was thinking that i should discard the idea of buying a very cheap bike and go for the aluminum mid range bikes. Is a 6 or 7 speed cassette required or could i purchase a bike with 8 or 9 cassette?

While the Raleigh above is an ok bike, i would be buying from the UK and paying the price shown. Here in Ireland at the moment is a tax incentive scheme to purchase bikes through your employer and get back approximately half the price of that purchase up to euro through tax. With this is mind i have also seen a few other options to a local chain store on some bikes. The brand is carrera however they sometimes have a reputation for requiring constant maintenance.

Here is an example:


John, LI-ghtcycle, neptronix - very interesting options there and i will make another post about my thoughts on all of your useful info. My head is awash with so many options

Specs
Lightweight alloy frame
Suntour XCM-V3 forks with 100mm travel
Alloy double wall rims with 26" x 2.10" Kenda tyres
Front and rear Tektro IO mechanical disc brakes
SRAM 24-speed gearing with SRAM X4 rear mech
SRAM chainset
SRAM trigger shifters

cost is 440 but would probably stand me 250 after tax. Well, you might see lower numbers. I carry big wind catching panniers, and raise the handlebars. Some days you'll have a tailwind and get 20 wh mi. Mostly you see about 30 wh/mi at 25, then it goes up a lot for any faster. Hills are another story, I did a ride yesterday up some crazy steep hills and got 70 wh/mi.

Again, if you are going to select a 2c discharge type lifepo4 battery, you pretty much must buy a 15 ah size. Otherwise you discharge at a c rate that lowers the life expectancy too much. BTW, the pingbattery 48v 15 ah is just about the biggest size that can be stuffed into triangles of bikes. And even then, it better be a big triangle. If carried on a rear rack, the 15 pound weight is just about as much as can be tolerated.

I must have been confused which bike I was looking at. I don't get the comment about maintenance, all bikes need a tune every miles or so. Disk brakes are not mandatory, I just thought you wanted them. I'll take em if I can get em though. I like the way trigger shifters work with half twist throttles. Twist shifters have to be dealt with somehow, to make room for a throttle. Removing the front derailur completely is common. Or get a lever shifter. 8 speeds are fine, just need adjustments to the shifters. 9 speeds in the rear are more likely to need a new deraliur and shifter, + wider chain to work with 7 speed cogs that come with motors.

Again, the main thing is get a frame with a generous sized triangle to carry that batery in. Hmmmm ...

I think i may need to lower my speed expectations in order to lower my battery weight. I am not commuting on my current ebike at the moment, but i was getting approx 20 miles to a full charge. 26v 9ah battery. All pedal assist since my current bike does not have a throttle. I would make my 13 miles journey in approx 50min - so maybe 15mph average speed.

Now i am thinking that i will not really be getting a significant performance boost for the amount of money that will be put into this

Here are some photos of the current machine:






The motor has now marking on it. But i think it is a brushless hub motor with 200W continuous. I was thinking of a 500W mac maybe. Is the difference large? Would the Mac be 500W continuous and peak higher??

Either way i could probably sell on the above bike for a decent price rather than mess about with it.

I have some other bikes lying around but i am uncertain of there suitability:

Candidate 1 - the crapper
The frame might not be too bad but has been lying around in rain and all components look shot. Was going to try give this one away


Candidate 2 - the skinny
700c wheels but i think again not suitable


Candidate 3 - the oldie
great bike in its time but it is a little small for me and i am not sure about the comfort


So all in all i should probably do a clear out first

I really do not want to go down the batteries in the triangle route since i am used to carrying plenty of weight on the back and handling is not a big deal for me. I more want briskness in the straight line. Must be rear motor. Fell straight on my shoulder in an icy spell last year. Front wheel began to slide on the bike and of course as the bike was sliding my foot was on the pedal and the motor engaged. Sore shoulder for a month. I thought not very safe for an off the shelf ebike. First of all, you need to decide how much you want to spend and get a clear idea of what you want to achieve. i think that if you use any of your existing bikes as donors, you'll end up wishing for better. You don't have to buy a new donor bike. you can get a perfectly good one on Ebay for half the price.

For £999 you can get an Alien Aurora that'll do everything that you want - ready made. Bear in mind that a kit cost about £250, battery £350 plus donor bike.
http://www.ebay.co.uk/itm/Alien-AURORA-Electric-Sports-Bicycle-Bike-e-bike-/?pt=UK_Bikes_GL&hash=itema0a6

To make your own ebike from a donor and kit takes a little know-how and a bit of ability to make things. If you have those skills, have a look at these that I made. For about £750, you can have a better bike than the Alien - one with proper full-suspension for about £750.
http://www.pedelecs.co.uk/forum/electric-bike-reviews/-giant-bafang-bpm.html
I use mainly a 10aH44v lipo pack for my 30 mile round trip commute and it does it easily, but I don't go very fast. If you want to go above 15mph, you'd be better off with a 20aH 36v Ping battery. As you've figured out, it's a lot of messing about to charge 20aHs of lipos. The BPM motor is probably the best value for money in the UK, the motors that our US friends use tend to be more expensive over here. A lot of pedelecs forum members have built bikes using the BPM kit from BMSbattery, so there'll be loads of help there if you need it. In the UK we need our bikes to be much more stealthy if you want to go over 15mph, so large 48v batteries and pancake type motors are very risky I think that you'll find a 350w BPM motor with a 20aH battery easily enough to do what you need and give a good balance between speed, climbing power, range, stealthiness and cost. If you have any questions about my builds, send me a pm through the pedelecs forum - or ask here. Well, it's true, for some of us wiring a new controller to a motor is a snap. For others, forget it. There are 8 wires, and you have to figure out what order to put them in. The colors won't match anymore most likely.

You could easily buy a kit and put it on that frame though. But at that point it starts to make sense to use one of your old bikes again. Round and round. Easy decisions if the budget has no limit, tough ones if budget is tight.

Perhaps a good approach would be to build the basic commuter I recomend often, and put off the date to do it till later if you must. Start with a decent direct drive motor kit. These motors generally come with 36v 20 amp controllers. Then depending on your need for speed, or more power to climb hills, buy a 36v 20 ah or 48v 15 ah lifepo4 battery. Pingbattery is my recomended guy. Budget in USD is at least $. But you get a very good bike that can go 20-30 miles, at 20-27 mph. The battery will fit in the triangle of some MTB's. Expect to get around 10,000 miles out of it. Hi All,

The Electric bike has been on the back burner for a while and sadly i am still in the car for now. It has come back into my mind recently that i must get a project underway for next spring and take to the roads again. What stirred my interest again was seeing a Big Turtle King Electric scooter on special offer in my own country. The Add said Yamaha. The max speed up to 45Km/h and the range up to 65Km/h. On further investigation the bike was chinese. Have a 60V/20Ah SLA Battery.

So low cycles for recharge and certainly not capable of the range and speed required for my 13 miles commute each way. Think i would be lucky to get half way at the 45km/h speed. Bike weighs 150kg. Add to this tax and insurance and the bike is a complete non-starter and the battery would be dead in two years.

So this has brought me back to bicycles. Really the only way to go. Cheaper, lighter, more bang for buck, no tax, no insurance and if stranded you can cycles or push it with ease.

I have been look more at some projects and more specifically Lipo. It interest me a lot as a way to get a cheap battery that does not add too much weight to the bike.

I was looking at various build threads on the kw/h consumed by various projects and it seems to vary greatly so i cannot guage with certainty what are my required:

I see over on pedelecs some figures as low as 5/10 kw/h
On here i see figures of maybe 20/kwh up to 20mph and then it goes through the roof after this.

So i was thinking between 20-25mph might be the sweet spot in the range/performance equation. Maybe even 20mph.

With this is mind the project i was dreaming of in this.

1. Found a very good deal on this bike and i love the look of the bike:



Pros:
Stealthy
Front Rear Discs
My preferred bike style for bike
Only one chainring and one sprocket with nexus hub (maybe a con)

Cons:
38t chainring and 16T rear sprocket with Nexus three (it is sufficient for pedal assist? at 20-25mph?)
Is nexus any good for an electrice project?
Motor must be front mounted.
Is front discs sufficient to clear motor?
Front dropout? Right for torque plates?

I am sure there are many other questions

2. Falcon Ev Frame Bag.



Stealthy. Looks like it is made for this bike. Colours and all. Could hold my lipo or lifepo4 batteries and maybe controller.

3. Batteries

Was thinking 4 of these to start me off. To give a 44V 10.4Ah 20C Pack ... mated to a cheap charger



http://www.ebay.co.uk/itm/mAh-2...sGames_RadioControlled_JN&hash=item19bccd

4. Motor

I was initially think of a Mac 500W kit but maybe i should look of the 350W Front kit since i am not looking for mad speed. In fact 22mph might be just right.

Questions: I hope you guys can helps out

The nexus 3 speed hub: It is any good for an electric bike? Maybe could change the sprocket from 16T to 13/14T. The Chainring at 38T i could change this to up the gearing. What do you think. Ideally i would like to leave the bike as standard as possible but also help out with pedal assist.

These lipos? Good or bad choice?

Range:
Ok so with this setup i would have 44V (more off the charger) driving a 350W front drive motor. 10.4Ah pack but many say only 70% useable. So 7.2Ah or so.

Then i would have 316 usable W/hrs. So 44V driving 350W motor with pedal assist to 20-22mph for 13 miles.

So i could only use 24W/hrs per mile. It is doable or not? Wouldn't be my first choice for a longish ride because of lack of suspension. But I'm old, have a wrecked back, got tired of breaking spokes because I no longer weigh 115 pounds. A lot depends on the road conditions where you ride. Here the heat cracks make it bumpy as hell.

The nexus means front hub, which I actually prefer on slowish street commuter bikes. Maybe you could pick out something with front suspension, and regular gearing. Then you get some suspension and could easily be sure to keep the front disk by using a rear hub.

Not that I can tell you what kind of bike you prefer. But there has been a definite trend among us here, to head towards full suspension for the second e bike, which is often intended to go 30 mph or more. Unless you raced, you may not realize how much the road vibration gets old when going that fast at all times. Most of us are used to going over 20 mph in short bursts, not for half an hour or more.

As for getting great range it's not really a matter of motor choice so much as choosing to pedal a lot, and not go so fast. In general, 20 mph takes 350 watts no matter what motor you are using. Pedaling to 10 mph before using the motor saves power no matter what motor you are using, and so on. The way you get 20 mph to take 200 watts is to PEDAL. Personally, I'd just carry 6 of those batteries so you don't have to be so tight on energy. Carrying 6 is generally pretty easy, and still pretty light. Hi All,

This thread is a little old but rather than start a new thread i have drag up my old one looking for advice. Again

My current ebike is out of action and i am currently cycling to work on a hybrid (no powerrrr), but it is amazing how the old body adapts. Takes me about 60min to do my 12.5mile commute one way to work. Not too bad and to be honest my old electric bike did not get me there much faster. I think when i was looking at the stats i was averaging 13.9mph on the old bike.

But i have still been building my new project in my head. It is definitely a slow burner. Since i was last cosidering a purchase of a potential project i have learned a little more and so can maybe be a bit more sensible in what i want to achieve.

From gleaning information and knowledge of the more experienced member here i have come to the following conclusions for my build.

1. Bike - Ideally full suspension and minimum front suspension. Because of the cost of a good full suspension i am siding with a decent quality hardtail when good triangle space.
2. Motor - Either a MAC 500w (8T)rear or a BPM 500W rear(siding towards the MAC). My commute is mostly flat but there are a couple of hills so i would like a little torque for these.
3. Speed - I must remember this is a bicycle and for a commute. So reliability No. 1 (for this reason i ignored the cyclone type motor). Initially i though more speeeddd, but by being more sensible i think it would draw too much attention. Also i am aware the efficiency Wh/per mile decrease rapidly as speed increases. So i think 22mph without pedaling capability would be sufficient (although i would always pedal). This would also avoid larger crank upgrades.
4. Battery - Lipo Out. I think Ping Out. A123 Cellman with high C potential seems the best at this moment in time. Now straight away i would say triangle pack 52v 11Ah but the reality is i think this is overkill for my targets. I can charge each side of 12.5miles and i think 39V 9Ah pack would be spot on.
5. Future upgrades - I want to select wisely and this is where the MAC 8T comes in. But then maybe i make the wrong choice with the 39V battery if i get the bug for future performance.

The reason for this post is i would like some more advice on potential bike choices. Again!!! I have spotted a bike on offer for a very good price and the moment. Very good spec for the price and i can get a tax break on it. Here it is

Voodoo Bantu


It is very good spec for the price. Suntour Raidon Air 120mm and Shimano Hydraulics 180mm front and 160mm rear

Would the 160mm rotor cause problems for motor install at the rear?

Need someone to critique the drop out. They are not flat so i would be thinking torque arm either side and not plates.



Here is another bike i have been watching but i think it is made from much cheaper components and maybe and bad FS?



Thank you in advance for any advice