Bike Forums

Bike Forums (
-   Electric Bikes (
-   -   PapaMotor 48v 1000w build (

Brainfarth 01-26-13 01:33 PM

PapaMotor 48v 1000w build
4 Attachment(s)
This has been an interesting adventure...
To start, I had to buy a bike that would hold up against the new components, so I found a 2009/10 Trek 6 series on craigslist for $400. Then I purchased a 48v 15ah PapaMotor kit with a 5 amp charger and the disc mount option for around $1200. I also bought a rear utility rack ($20), new Hemisphere 26"x1.95" tires ($130 mounted), rear mount kickstand ($20) and tons of other miscellaneous stuff.
Getting the battery here from China with the new Lithium restrictions was a real pain and turned into a lengthy delay. Hopefully they have found a faster shipping method since then.
I had an issue with the freewheel going out, so I had it repaired and upgraded locally. I'm sure they would have warrantied it, but I did not want to wait for the replacement to be shipped here.
Another problem was with the BMS(battery management system) not charging correctly. They shipped me a new one after I sent them a picture of it with one of the lights that would not turn off.
All in all, I am pretty happy with the setup. I have been riding it 13 miles every day, to and from work. Pouring down rain and temperatures in the 20's have only slowed me down a little.
To the pictures...

Brainfarth 01-26-13 01:36 PM

1 Attachment(s)
An issue that I have address very soon is the lower mounting bar for my rear rack. It has bent and I'll have to replace it with something stronger. Dropping off of curbs has done this damage.

Brainfarth 01-26-13 01:40 PM

1 Attachment(s)
I found that the battery fits great in an old tackle box. I used a piece of Styrofoam to fill the void and keep it secure. Also, I mounted the breaker switch so I could flip it from outside of the box. Remember to check all of your wiring connections. I had quite a few that were loose.
I plan on installing a waterproof key switch in the future, along with a trailer plug for the battery plug-in. I'll post those modifications when I get that far.

Brainfarth 01-26-13 01:45 PM

2 Attachment(s)
I had to modify the thumb throttle a little to keep it from hitting my gear selectors. I didnt want to move it farther away because it would have been difficult to reach the other levers. Also, I busted the plastic cover for the low-battery light on the controller by flipping the bike upside down to work on something. You may want to place somekind of spacer to keep this from happening to you.
I used the break levers that came with the kit for a while, but I was not impressed with their quality. The adjusters stripped out after 2 weeks, so I changed back to my old levers. The kit ones have a safety option that kills the motor when you hit the handle, so I figured it would be fine without them. And to keep the look clean, I drilled a hole in my frame for the throttle control cable.

Brainfarth 01-26-13 01:55 PM

1 Attachment(s)
I mounted the motor controller to the upright post on my bike. I was able to use the mounting point for the old cut holder for the lower side of the controller and a ziptie on the top side. I cut down a few cables because they were so long and wrapped the whole group in a plastic bag, then a piece of fake leather. They still get a little wet, but this has not caused any issues as of yet. I would love to hide everything in the tackle box, but I think the controller would overheat in there.

Brainfarth 01-26-13 01:59 PM

2 Attachment(s)
One bad thing about the Rockshox is there are no decent fender options. You can find one on the frame, but you still get hosed with water and road debris. I bought a cheap plastic kit from Fred Meyers and modified it to mount on the cross-over. It works pretty slick. Eventually I'll put on on the back because the tire spits up all over everything back there.

Brainfarth 01-26-13 02:07 PM

1 Attachment(s)
I opted for the disc brake adapter plate, which I did not have to use after all. All I did was get some bolts that were 1/4" longer and then I used washers to push the caliper out to the correct orientation to the disc. But I did have to use the disc mounting nut (they call it a female screw). Mine are 44mm x 6 hole.

Brainfarth 01-26-13 02:37 PM

Ebike range and speed
I forgot to add: The bike pushes me to a little over 30mph (I'm a big guy) on flat ground. With no help peddling, I can cruise a little under 20 miles at or around 20mph. If you gun-it for long periods, your range falls short.

EBikeFL 01-26-13 03:03 PM

Congratulations, Brainfarth. :thumb: The e-bike looks great. I couldn't help noticing the cluttered dining room table with tools and parts...looks just like mine. :roflmao2:

You may want to use a 3M weather stripping sealant to seal that drilled hole. Keep an eye on it being so close to a weld point.

From the looks of your rear disc rotor it looks like your brake pads are only contacting half the rotor. You may see better stopping power if you can get the entire brake pad to contact the entire height of the rear rotor.

How do like 30 mph? ;)

Keep us posted on any changes and a great write-up once again. :thumb:

EBikeFL 01-26-13 03:38 PM


Originally Posted by Brainfarth (Post 15201412)
I also bought a rear utility rack ($20), new Hemisphere 26"x1.95" tires ($130 mounted), rear mount kickstand ($20) and tons of other miscellaneous stuff.

I tried the Armadillo Hemisphere on the rear as well and found the ride very harsh. The tires may be bulletproof but I hated the feel of them. If you want to stay with 26" x 1.95" tires, you may like the Schwalbe Marathon Supremes which are also bulletproof but not as stiff as the Hemisphere.

I'm currently using Schwalbe Big Apple tires in the 26" x 2.35" size and love them. They give the feeling of riding on an air suspension but don't make you feel like you're riding 10 feet off the ground like the Schwalbe Fat Frank tires did. Using a set of these Big Apple tires may solve the issue with you bending the rear rack...of course, staying away from riding off curbs will help too. ;)

Brainfarth 06-20-13 10:48 AM

Update: My Ping BMS failed so they sent me another. It worked great for a while, then it started to charge the cells unequally. So I gave up on their BMS and contacted for a custom one. After a confusing install, I got it working and it ballanced things fairly quickly and I got my range back. Unfortunately, one of the cell connectors on the board broke, so I replaced it with another. I think there are other issues because it wont charge now, so I put the old Ping BMS back on and I'm limping by until I can get it repaired or replaced.
Here is a video I created from a recent ride:

Brainfarth 06-20-13 10:57 AM

1 Attachment(s)
The new BMS I purchased supported data logging. So I could get real-time information on each cell and many other bits of information.

powell 06-20-13 05:01 PM

Is this video in fast forward mode?

Jimi77 06-21-13 12:02 AM

Nice build and good luck with the battery and bms.

slickdude 02-22-14 08:50 PM

The main key to buying the Papamotors is the Torque and axel width. 100mm for the axel width if up front, more for the rear setup. My suggestion is go a front hub unless you are doing a lot of steep mountain climbing. The key besides the width of 100mm is make sure the front forks are made of steel. There is a reason for this and it is a major safety issue.

Polycarbon and Aluminum crack without warning. Steel cracks slowly ;) and at speeds, this makes a significant safety difference. The reason for the front setup is it is easy, quick and unless you are climbing steep grades like you are using this for more road riding, it's a natural. Instead of spending 400 dollars, remember the cheapest steel bikes make the best candidates because of the aforementioned.

Now, if you want a real performance monster, you might try considering a Polycarbon bike and replacing the front forks with steel forks. Then dropping in your wheel/motor hub. That will leave everything else super light on the bike. Make sure if you are going for top end speed to go for a 700 style wheel for more onroad rides or a 29" for the off road. Bigger wheels move you faster ;) Papamotors does make a 700 sized hub in a 1KW configuration.

Wambalam45 02-04-15 02:23 PM

Brainfarth, how did you get the disc base to install onto the motor as seen on page 12 of v1.5 manual, picture 2.3.6-2? My original wheel has a solid disc base fashioned into the axle and cannot be taken off.

christo930 02-06-15 02:11 AM

I think it's time for a new chain:) That was the first thing I noticed when I brought up the close-up of the rear of the bike.

All times are GMT -6. The time now is 02:37 AM.