TexasElectric - eBike build

[Grant-53]

Look for mountain bikes with the spring/shock parallel to the seat tube. Or my Jamis Aragon has a shock seat post and spring handle bar stem along with a spring seat. Very comfy and light with the aluminum frame.

[TexasElectric]

teoman
I've investigated the idea of using a plexi-glass tube to put the cells in series, but the problem I ran into was the cells have a 32.75mm diameter and the closest sized tube I could find was 1 1/2 inch (38.1mm) inner diameter tube. I'd have to play around with securely filling the 5.35mm gap between the cells and the inside of the tube. For the time being I've tabled the idea.

samwichse
I've since backed away from my plans to solder the cells. I'm going to spot weld them.

PS. I'd love to have "screw terminaled" cells, sounds like they'd be easier to work with.

I'm considering kits from eBay. There is a seller in Michigan "eBikeling". He sells Chinese no name hub motors, and brands them with his companies name. I know this because his hub motors and rims use the exact same make/model parts as most other no name Chinese hub motors on eBay.

48V 1500W Direct Drive REAR 700C eBike Kit Electric Bicycle Ebikeling | eBay

What's nice about this guy "eBikeling" is that he is based in the US and offers free shipping, whereas the Chinese sellers are asking over $100 for shipping to the US.

I know about the stigma of buying no name Chinese products. Although, 3 years ago I purchased a set of no name Chinese carbon fiber wheels for my road bike on eBay. I put around 2,000 miles on those wheels, I had multiple situations where I was riding at speeds in excess on 40+mph with no concerns of them failing on me. I sold the wheels right around 2,000 miles of use because I needed the money more than the wheels, but they were still in good condition when I sold them.

My thoughts with this motor is that (irregardless of who/where I buy it from), I plan to only use this 1500w motor at 1/3 or less of it's full potential and by doing so it should last a long time: as apposed to buying a 250w or 500w motor and pegging it at 100% every time I use it. Plus it doesn't hurt to have a little extra power.

Grant-53
I will look into mountain bikes with suspensions in that configuration.



Update on where I stand today
Last week my BMS arrived from China. (fast shipping, only took 10 days)





In addition to the BMS, the Kapton take I ordered arrived. I need to re-place an order for Nickel strips. I accidentally bought Nickel platted tape instead of strips.

I am moving at the end of this month, but before I can move I have to take care of some maintenance to my home. In my free time I will continue working on assembling the battery.

I flip-flopping back to the idea of using a 29r mountain bike. My research online (as well as talking to the local bike shop mechanics), tells me that 29r mountain bikes use 700c rims (same as road bikes). My biggest concern is being able to find a good quality bike. I know Specialized makes good quality bicycles, (as I am currently thinking about buying a brand new RockHopper 29r for this build). But finding a used 26" name brand mountain bike (full suspension or hardtail) that's my size, in good condition and priced around $500-$700 is hit or miss.

Lastly, this is a new configuration I am looking at for my battery. The battery pack (once assembled) would be mounted on the down tube.

5p, 16s



I don't wan't to come off sounding like a snob when I talk about buying a brand new name brand bike. In the past I've bought el-cheapo stuff (electronics, bikes, cars, etc...). Sometimes you get lucky and you discover a diamond in the rough, but generally speaking "you get what you pay for." My current bike is a Colnago cyclocross bicycle. It's not cheap ($,$$$) by any means, but I've had it for over 3,500 miles and it's required very little tweaking/tuning and takes a beating from time to time.

For my e-bike build, my feelings are that the bike is the foundation (and should not be skimped on). The Batteries I bought are good quality (not el-cheapo). The motor I am considering (from eBikeling) is rated for 1500w, if I only use 300w-400w of the motors potential it should last a long time. Likewise the BMS I bought (albeit a no name Chinese brand) is rated at 48v 60a, if I'm running 6-8 amps through it, it should also last a long time.

I would have purchased the BMS through a name brand US seller, but I was unable to find a LiFePO4 48v 60a BMS for under $100 in the US.

[samwichse]

This is going to come as a weird recommendation, but Costco's mountain bikes are a steal for the quality:
http://https//m.costco.com/Diamondba...100303215.html

The tube welds are nice and even, the hardware is all decent mid-grade stuff... if you can get over the Diamondback name, you won't find a nicer ebike project base for $400 IMO.

Specifications
Color: Green
Frame: Overdrive 27" Butted 6061-T6 Aluminum with Formed Top / Down Tube, Machined Headtube, Forged Drop Outs with Replaceable Hanger, disc only
Fork: SR Suntour XCT, 80mm Travel, Coil Spring, 28.6mm Stanchions
Headset: FSA IS-3 Integrated
Cranks: Suntour XCT, 42/32/22T
Bottom Bracket: Square Taper - 5pc
F. Derailleur: Shimano TX50, Top Swing, Dual Pull, 34.9mm Band Clamp
R. Derailleur: Shimano Acera M360 8spd
Shifter: Shimano Altus EF-51 8spd
Cogset: Shimano HG-31 8spd Cassette (11-32t)
Chain: KMC Z82
Brakes: Tektro Aries Mechanical Disc w/ 160mm Rotors
Brake Levers: Shimano Altus EF-51
Front Hub: 32h SL-7 Alloy w/ CNC Disc Mount
Rear Hub: 32h SL-7 Alloy Cassette w/ CNC Disc mount
Spokes: Black 14g Stainless Steel
Rims: DB SL-27 27.5" 32h Doublewall
Tires: Chaoyang Hornet 27.5x2.1
Handlebar: DB Laser Series, Low Rise, 600mm Wide, 31.8mm Bar Bore
Grips: DB4L 135mm Kraton
Stem: DB AL6061 Ahead, 31.8mm, 7°
Seatpost: DB Micro Adjust 30.9mm
Seat: DB Race s M-series saddle

You can usually find them in store if you want to go take it for a spin, although beware the store demo models are apparently assembled by chimpanzees (out at least employees with no clue about bicycles). Is be using one myself if I wasn't so in love with my old Trek 820.

[Grant-53]

The Diamondback bikes are well known. Mongoose built a suspension with a lever and a shock just in front off the seat tube. Lots of options.

[TexasElectric]

samwichse & Grant-53

When I got back into bicycling (4 years ago), the bike I purchased was a DiamondBack mountain bike. I grew up riding DiamondBack mountain bikes. I like the brand a lot. I have given consideration to their bikes, kind of a maybe...

I rode with a guy for 2 years, he had a GT mountain bike. He liked it a lot, no problems. There are definitely other options.

[samwichse]

I only meant that some people get snooty about them because Wal-Mart sells some of their cheaper bikes.

A lot of people won't get caught dead riding a "Wal-Mart bike" for... ego(?) reasons. No matter what the quality.

[vskid3]

Originally Posted by samwichse

I only meant that some people get snooty about them because Wal-Mart sells some of their cheaper bikes.

A lot of people won't get caught dead riding a "Wal-Mart bike" for... ego(?) reasons. No matter what the quality.

Do they sell Diamondback bikes? I've never seen one in their stores and the only 2 I can find on their website look like they come from third party sellers. Walmart has some decent bikes if you know what you're looking for and/or upgrading most of the parts, but the average person looking for a reliable bike would probably be better off visiting a bike shop.

TexasElectric- With the lower speeds you're planning on riding, a decent hardtail with wide tires should do great. You'll have a lot more room inside the triangle for your battery, too.

[Grant-53]

There was an issue with some of the low end bikes such as Next having poor wheel bearings and clunky components. I'm building a mountain bike out of spare parts and a Next frame left for junk. If the screwdriver fits your hand use it. If someone wants to name their dog 'Phydeaux' let them. My Huffy 3 speed will be 50 years old this spring!

[Shortie771]

Definitely following this. Keep up the good work! Will pedal power assist in recharging the batteries on this?

I've been floating around the idea of building an enclosed electric reverse trike for running into town (about 4 miles) for things. Maybe even to and from work, but that's about 15 miles of mostly interstate each way.

[vskid3]

Originally Posted by Shortie771

Will pedal power assist in recharging the batteries on this?

Some kits/controllers support regen that's enabled through either the brake switch or another switch. They're good for recovering some power when braking, but you're better off to power the wheel directly with the pedals than trying to charge the battery. It's more efficient to power a bike with electricity than a human/food, so trying to use a human to charge the battery will just make the human power that much worse (PDF of a paper comparing ebike to human powered bike). You can pedal in addition to the motor for increased range or acceleration, but it doesn't actually charge the battery.