Hi Forum! This is my first post but I have been reading and researching for several weeks.
I'm going to be building my first ebike over the summer, the intention is to commute to work and back on nice days, but I would also like to have a little recreational fun with it too. (Not racing or difficult single track trails etc...)
My route is 12 miles each way and contains a little bit of everything, bike paths, city roads with and without bike lanes (25mph), and paved country roads (45mph) with narrow paved shoulders, there are one or two hills and they aren't very steep, but long.
On my morning commute, I spend almost an hour in traffic and spend about $4 in gas a day. It would be nice to not have to do that anymore with the option of working to get healthier. I weigh about 185 pounds height 6' (not fat) and I have strong skier legs although my cardio fitness isn't that great. I'm very lazy.
I will be able to charge at work if I can take the battery inside, but my bike would be locked to a rack where I can't supervise it all day.
I don't necessarily care about it being 20mph/750W legal as long as it looks more like a bike than anything else.
This is a very popular bike city with bike lanes, dumb bike cops and smart bike thieves, so I have to be careful with how things look. Tinkering Background:
I have an extensive background with mechanical and electrical things. In my man cave I build 5KW tesla coils and large electric/nitro RC helicopters. I'm not as familiar with bikes. I could put one together but I don't know how to lace a wheel, repair chain links or install/uninstall a freewheel. (I could learn, but I want to keep my first project very basic.)
Here are my requirements:
o Able to go at least 12 miles in aforementioned conditions in under an hour with no pedaling. Less is better. (It takes me 45 minutes to drive.)
o It has to look like a bike. Nothing in the frame triangle. No explosive device looking things with wires out. No questions from cops.
o Expensive parts (battery/controller) easily removable and/or lockable.
o Full suspension.
o Disc brakes.
o Safe Lithium Battery
I looked at some of the pre-assembled retail ebikes and didn't like the way they looked (not like a bike), price/power wasn't optimal and they look difficult to repair or upgrade. I took a look at the BionX kits, and they look they have the performance but seem proprietary, which means expensive and difficult to repair or upgrade, and also not a big fan of the LiMn battery chemistry.
So with all that in mind I have decided on the following components as potential candidates, I want this to last me a long time so I am being conservative with ratings.
I'd like to run it by the forum for a sanity check before I pull the trigger and buy it all:Battery:
48V LiFePO4 Ping Battery, either the 15Ah or the 20Ah:http://www.pingbattery.com/servlet/the-12/48V-15AH-V2.5-LiFePO4/Detail http://www.pingbattery.com/servlet/the-2/lifepo4-lithium-ion-phosphate/Detail
The 15Ah says rated at 15A, continuous 30A, cutoff 40A. 720W,1440W,1920W
The 20Ah says rated at 20A, continuous 40A, cutoff 50A. 960W,1920W,2400W
Never had a LiFePO4 battery before, only the LiPo sausage exploding fireball kind in RC.
What's the lifespan difference in running a Ping LiFePO4 battery at its 1C rated vs. 2C continuous discharge rate?eBike Kit:
I think I'd like get the 48V e-bikekit.com rear direct drive kit: http://www.e-bikekit.com/shop/index.php?p=product&id=136&parent=4
I am curious as to which brand of controller and motor hub this kit uses. Is it the same as the suspicious Chinese ones on eBay?
The specs from e-bikekit.com list this controller as 20A @ 48V which would be 960W.
Is this a continuous rating or one of those Chinese maximum theoretical we dare you to try for more than a minute
What's the real deal here?
If it's a continuous rating, then should I pick the 20Ah Ping battery, or if a max rating, then the 15Ah Ping battery?
(Remember, I want to be able to ride the whole 12 miles in under an hour, without pedaling, faster is better.)
This kit comes with special brake pulls, is that for regenerative braking or just simply to cut the power to the motor?
If not for regen, is the motor compatible with regen if I want to upgrade the controller later? (I am fine with soldering etc...)Bike and Bike Accessories:
This is the area I'm most clueless, so most questions.
About the only thing I know for sure is that an aluminum framed bike needs reinforcement in the dropout/forks to prevent torque stripping.
(I have RC helicopter experience and fun stories of how torque loves to modify weak aluminum/plastic parts.)
I am familiar with DoctorBass' torque arms and might get some if they are still available. Or make my own.
I have this bike in mind because it has the most good ratings on Amazon and meets my requirements of disc brakes and full suspension: http://www.amazon.com/GMC-Topkick-Dual-Suspension-Mountain-Bike/dp/B000BT4W2C/ref=sr_1_1?ie=UTF8&qid=1332192244&sr=8-1
The only fault the reviewers say consistently has is that it weighs a ton, but they say it's a good value.
Since it will be electric powered, weight is not a huge deal.
It's also a 700c bike, so I am interested in what the going opinion is on 700c vs 26" in ebikes?
Also any thoughts about mounting a battery on the back of a full suspension bike?
Are there any good seatpost racks that are up to this task?
(I have the machining skills to make or modify a mounting platform.)
Sorry for the long post. I want to make sure I do this right.