Help With First Build

Joined
Oct 6, 2015
Messages
10
Location
California
I am looking to build an electric bike.
See the thing is though, I'm under a budget so trying to keep costs mostly down.
You think I could get a cheaper deal by buying individual parts and putting together a bike myself possibly?

-Aiden

https://www.lesswrong.com/posts/o5PojLYFEWtyeo4ct/the-ai-that-pretends-to-be-human (The AI That Pretends To Be Human)
 
ilikepancakez said:
Located in the U.S.
Not according to your profile; that says you are in Zimbabwe.

Which is true?
 
Not much you can do to change the type of brakes you have on that frame. But different pads can make a ton of difference, and if you must, upgrade to better grade road bike rim brakes. They don't have to be poor brakes, but you can't go to disc without disc brake mounts on the frame.

The handlebars are not made for ebike throttles, but a thumb throttle could work ok. I'd put flat bars or riser bars on it for a commute. You won't see the truck that kills you riding in a racing tuck, in city traffic. So change the handlebars.

Ok choice for a cheap kit. Most get a kit that works fine, for a bargain. It should last a long time. The battery too, but too small for 30 miles riding fast. At full cruise of 25-30 mph, you will get about 12 miles or so. It will go 30 miles, but only by riding slow, so your pedaling is 50% of the energy needed. Like 15 mph or slower. Charge at work if the 30 miles is a two way commute.
 
That bike is not a good bike to convert you need a good used MT bike that already has Hyd Disc brakes look on craigslist you will find a ton of them almost all will be a better choice then that bike . You don,t want to use 700 wheels or the road race bars.
 
The motor kit is 26", so you need a 26" bike with V brakes, not caliper that suck. The bike should have steel dropouts, not aluminum. You'll need close to 1000wh of battery for 30 miles @ 25 mph on level ground. And more in hilly conditions, or slow down to 20 mph. Replace the tires with 2.125" or larger for best ride. there are lots of suitable bikes for under $200 new from hardtail cruisers to DS mtb. Road bikes would not be a good choice imo.
 
That's the wrong type of bike o convert with a 1000w motor. If you wnt 30 mph, you should get a strong MTB frame with disc brakes. It's a lightweight road bike with thin tyres. It's just not designed for the weight and torsion of a 1000w ebike kit.

It's possible to get it up to 30 mph with a lightweight motor and battery as long as you want to pedal hard and you switch off the power below 15 mph. It'll slow own a lot on a hill.

With the right kit and moderate pedalling, 25 mph and 30 miles should be possible. Don't expect it to be an electric motorcycle though.
 
I think the chemistry of the battery you are looking at is Lithium Cobalt. It has many good attributes. But this is considered to have risk of fire more than the other lithium combinations. Consider Lithium iron phosphate. (LiFePO4) A lot safer but it will draw power a little less.
 
There's nothing wrong with that battery. It has Samsung cells, so relatively safe and half the weight of LiFePO4.
 
I am also doing a first e-bike build. I choose a Giant Escape 3 as my builder. I have already converted it into a Giant City. I am in Phoenix Az. Home of Lectric Cycles. I have ridden a few bikes with their mid-drive system and it seems to work very well, but it is kinda pricey. In the beginning I wanted to GO BIG with a 750 watt motor & 48 volt battery. Today I rode 2 e-bikes both with 500 watt motors & both were made like the Giant Escape. I was able to reach 30 mph easily.

I'd like to know what is the best combination of motor & battery-that will give you the best of both worlds (SPEED AND DISTANCE)?
 
Drop bars are fine with a thumb throttle. I used some PVC pipe to provide a spacer and cable ties to strap it to the inside of the left hand shifter. You just move your thumb down and pull it towards you to throttle up.

throttle_dropbar.jpg


Better pads will make a big difference to your braking ability but then it comes down to your tires. This is where the thin tires sorta suck and alot of people get MTB frames for balloon tires and bigger contact patch. See what the fattest tire you can put on the frame is.

My cyclocross is based on a 29er frame (big 2.2" tires) with a BBS02 750w with a 48t chainring. Easily cruises to 50km/h and the central weight distribution is good for handling.
 
Are Samsung Lipo batteries immune from the dangers of lithium cobalt? Are the risk factors the same as LiFePO4? If they are the same then why use anything but lipo?
 
Samsung batteries are as safe as any. They're the same cells as what's in your latop. You have nothing to worry about.
 
Raged said:
Drop bars are fine with a thumb throttle. I used some PVC pipe to provide a spacer and cable ties to strap it to the inside of the left hand shifter. You just move your thumb down and pull it towards you to throttle up.

The easiest way to fit a throttle to a road bike is with one of these, which positions it in a convenient position.

http://pages.ebay.com/link/?nav=item.view&id=111765295778&alt=web
 
lap tops in the beginning were starting fires with Lipo. The engineers redesigned them to draw less power and solved the problem. If Lipo starts on fire you can not put it out. They generate oxygen in a fire and it goes out when the oxygen is done. What about LiMn2O4? A lot lighter than LiFePO4 and a higher discharge rate?

Regardless of who makes it, LiPO has more risk. It is what grounded the 777' dream liners. They had to build an elaborate box and exhaust system to protect the plane when the next event happens. They should have used a different Lithium chemistry. Then no box or exhaust system. Save the weight and space. And I have heard of LiFePO4 that can be made with very high discharge rates.

I think the perfect application for Lipo is racing. And phones and laptops. Either to go real fast or when space is a premium and the power demand is low.

Would you put the Samsungs in an airplane as opposed to LA batteries? I would not. Nor in a marine application. It would work. But what if in .25% of the time (1 in 400) it would flame? Not good enough.
 
IMO, the problem with the 787 dreamliner was the design of the rear battery pack using 5C rated cells and pulling 20% or higher amps than it was rated for. It has 2 of the same batteries, and they only had the problem with the one that draws more amps than it was rated for. The whole thing could have been avoided if they didn't have idiots designing them. The box to vent them wasn't really a fix. I assume they've corrected the design problem by now by using higher rated batteries, limiting amp draw and charging via the bms or a combination of the 2.
 
They kept the batteries. That is why they built the big box and venting systems. For all their needs with less space and weight considering the box and vents, they could have changed to LiFePO4 with less space and weight. I know the attributes are better with lipo except the risks. How is it possible that the risks are the same?

When someone asks what my rig weighs I answer it is weightless. The power overrides the weight. Unless racing is the focus I don't care if the battery is a little more weight. I don't want lead acid but 4 or 5 pounds more is not an issue. I now have an all cell LiMn2O4 and that is lighter than LiFePO4 and it will draw more power. And less risk than lipo.
 
18650 cells are half the weight of LiFePO4. They're used in just about every OEM electric bike now. There must be a reason for that!
 
Probably because, the oem bikes are slow as crap with low wattage motors and controllers.
 
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