Need help on a motorcycle project

kamikazee,

Welcome to V is for Voltage, we do have several members who can help you with your project. I believe your project is very realistic with one exception, cost. To build what you want will require some very high dollar batteries, Lithium Ion, to get the range and speed you want. I think you should know you cost estimates are very low.

I build e-bikes and my e-bikes are in your price range so I am sure you can see you will need to revise your cost estimate. I will not guess at something I don't know but don't give up on your idea, it is a great way to go.

One of these days I hope to be able to purchase or build a motorcycle with the following requirements. 60-MPH with a minimum range of 60 miles.

Good Luck,
Chas S.

Oooo, sounds fun! I wish I got paid more so I could do the same (only work like 14 hours a week, but still good for a 16 year old, I guess). You're lucky. You have family to help. I don't know anyone who does cool stuff like that.

Anyway: A lot of people like that motor. I know Andrew (on this forum) has done a similiar conversion with two Eteks, so I know it's a realistic project. Whether you can do it under your budget, I couldn't say. Just guessing I would say you would have to find some really good deals to do it. Figure that the electronics (Etek, Alltrax, wiring, fuses, solenoids, etc.) might well cost you $1000.

Andrew uses a Curtis, but an Etek with an Alltrax controller is a popular combination.

In regards to batteries, you really have three basic options:
1. Lead acid. These are the cheapest (initially) batteries available. But, you get what you pay for. They are not very energy dense (big and heavy for their capacity), and do not have a very long cycle life (a few hundred at best). They also cannot be discharged all the way if you want them to last more than a few months.

2. NiMH or NiCD. These are the mid-range batteries. They are more energy dense than lead acid and last longer. They can be discharged further than lead acid, but, as with all batteries, last longer if you do not deep-cycle them. They are about 2-4 times more expensive than lead acid, but may save you money in the long run, since you do not have to replace them as often.

3. Lithium. These come in various flavors. The most popular right now are LiFePo4. This chemistry is currently the best you can get. They have far higher energy density than lead acid or any of the nickel chemistries. They are also far more expensive. A motorcycle sized pack will easily be into the thousands. But if somehow you can afford them they are definitely the way to go. Remember, however, that they supposedly have an unbelievably high cycle life (2000+ stated), so might be cheaper than lead acid in the long run. A123 cells (used in DeWalt 36 volt tools) are some of the best you can get. They are small, though, so you will need lots of them, and a potentially expensive balancing system.

In regards to how many you will need, I cannot really say. It depends on the chemistry. If you use lead acid, you will need four (12V batteries) if you want to run the Etek at the rated voltage, but some have run it at 60 or even 72 volts, which would require five or six batteries, respectively. Capacity wise, you pretty much whatever will fit on your bike.
If you used NiMH or NiCD, you will need 40 (1.2V cells) to run them at 48 volts, or 50 or 60 to run at 60 or 72 volts. Get the idea? Mind, though, you may have a hard time finding big enough cells.
Lithium cells are 3.3 volts nominal. I let you figure out how many you need ;).

There's all sorts of little things that might come in handy to know. Read around here and you'll find out a lot. If you need some help, you know where you can get it :).

Hi kamikazee,

Check out my conversion in progress: http://visforvoltage.org/blog/jdh25501/2347 - I just started mounting my batteries this weekend (2 done 5 to go!)

I got the bike free. So far I've spent $1000 on batteries for 7 75Ah batteries (when you add in shipping costs and the high price of lead right now) and about $600 for a Kelly Controller and two DC/DC converters. I've also spent about $40 on metal supplies. Next up I'm about to buy an ADC motor and all the various switching and cabling - that will probably be another $1500 ish. So, I'm a little over your upper limit of $3000. And that's without paying a dime for the bike.

Some random notes:

- Choose your bike that you're going to convert. I'd suggest something in the 600+ cc range - a bigger bike gives you more space to put stuff. Of course if you're lucky enough to find something for free then figure out how to make that work!

- You might not need as much in the way of batteries that I've opted for - I'm aiming for a 50 mile range and a 65mph top speed. I'd suggest that with your budget you should only consider lead acid. You can always upgrade to lithium later.

- I went with an Advanced DC (which is just a brand name - nothing advanced about it!) series wound motor. They come with more powerful output and they're more robust. They're bigger and heavier and less efficient than the ETek or the Perm132. One of the problems with the Perm is that it rotates the wrong way for my installation (it can work in both directions but is not as efficient when run the way I'd need it to).

- Andrew was very helpful when I started my project - but he seems to have dropped off from this board of late? He steered me towards the ADCs rather than the ETeks (even though he has a dual Etek setup)

- I went with a Kelly controller. They're new to the game - but they were less expensive and they rate their controller up to 84V (I'm going for 7 x 12V = 84V system). It's programmable like the Alltrax and if you go with the Etek or other Permanent Magnet motor they do a version with regen braking capability (not for the ADC series wound though).

- I've got a nifty spreadsheet (well I think it's good!) at: http://www.editgrid.com/user/jdh2550/CB-72V - if you play around with the figures on the summary tab (the last tab) you can see how additional weight affects required torque. It also plots available torque for the Perm132 (which is a more powerful equivalent than the Etek, and an ADC). If you want to play with it - go to the URL and either choose Export and save it as an Excel file on your PC or do a Save As... and create your own copy to play with online. If you want more explanation of the calculations drop me a message here or email me (you can use the links beneath this post to contact me).

- Two books I recommend are Bob Brandt: Build Your Own Electric Vehicle & John Bidwell: Secrets of El Ninja. The first is geared towards cars and trucks but has a very good coverage of all the math to figure out required torque. The second is a much shorter read and is about a conversion of a Kwakky Ninja 900cc (might be a good choice for you to follow that to the letter?). Note that some folks don't think Bidwell's design of motor on the swing arm is good - others think it's great. It wasn't an option for me with the CB-750.

- There are lots of web resources (google for the EV Album) and most folks are happy to answer questions.

Good luck! And remember to have fun - if it doesn't work out quite how you expect it then don't worry you've still learned a lot, right? That's my philosophy - but so far (touch wood!) things are going OK - I hope to be riding my CB-84V in early spring next year...

That looks like a nice conversion - I've never seen a motor mounted like that before. You might want to ask him if he likes that design and why he changed it from the El Ninja position. You can increase the top speed by reducing the size of the rear sprocket - but you'll sacrifice acceleration - you will also need to calculate the required torque to push the bike at 100kph and make sure that the Perm 132 @ 72V is up to the job. It probably is.

Bear in mind El Ninja is an older book - the batteries will likely cost you more and I'd say $1750 (the price of a Perm 132 based kit) + the price of batteries is your bottom line. Will you have to replace the batteries often? Hmmmm - there's a hot topic! Don't have time to answer it now - but search on this forum for some discussions to see how involved the answer can be...