Homemade Day 6 Electric Bike 48 Volts 1,000 Watts

Boyntonstu

New Member
This is my Day 6 Dream semi-rcumbent bike. Low CG and very stable.

Currently using four Walmart Booster 12V Lipo batteries in series.

It needs higher gearing to pedal assist over 17 MPH.

It can go 30 MPH.

This is by far the best bike that I have ever owned.

I was very lucky to find it in a pawnshop for $200.

FYI http://www.day6bikes.com/ I have no business connection with Day 6 bikes.

Unfortunately, a loud bearing type noise appeared at the end of the video. I will have to get inside the motor to determine the cause.

 

Berry78

Active Member
Welcome! Looks like a comfortable bike :)

Please do be careful though. 30mph crashes can't feel good.
 

George S.

Well-Known Member
Interesting concept, all the way around. I'm trying to figure out your battery pack. Are these the booster packs designed to jump start car batteries? I've used LiPo packs that were meant for drones or model cars, etc.

I like the bike. I have a basic cruiser (in my picture to the left) with a front hub. Having a seat back might help. That's a very long bike. I notice they sell the bike with a mid-drive motor and even offer a Rohloff hub. I've had good luck with just a couple of gears for pedaling but a high enough gear is generally the problem.

Definitely an interesting bike and power pack.

Screenshot 2016-09-19 at 7.52.06 AM.png
 

Berry78

Active Member
Thanks George, for the link. Very interesting looking bike, though from their videos it appears that everyone has his/her arms outstretched pretty far. Makes me wonder if that position would be tiring after a while.

This is definitely catching my eye for my daughter with the spinal fusion. Have to scrounge one up for a test ride.

Thanks, @Boyntonstu !
 

Boyntonstu

New Member
I purchased 4 of these 5,200 Multistars on sale at Hoby King for about $144 including shipping:

Multistar High Capacity 5200mAh 6S 10C Multi-Rotor Lipo Pack

I also got 2 of these rerminal strips on eBay: http://www.ebay.com/itm/172176881092

I will use the strips for cell balancing and for cell Voltage readings.

There are several wiring possibilities:
48V with the batteries in series/parallel.
A pair of 48V strings, one to go out, and a switch to the other string for the ride back.
3 of them in series (1 left as a spare) and a 72 V controller for a fun experiment:

http://www.ebay.com/itm/72V-1000W-Electric-Bicycle-Brushless-Speed-Motor-Controller-For-E-bike-Scooter-/391558687426?hash=item5b2ab76ac2:g:tTgAAOSwM0FXIIWy

My 6 mile rides were OK using the mediocre Walmart Booster 3.5 Ah batteries,
 

Boyntonstu

New Member
Interesting concept, all the way around. I'm trying to figure out your battery pack. Are these the booster packs designed to jump start car batteries? I've used LiPo packs that were meant for drones or model cars, etc.

I like the bike. I have a basic cruiser (in my picture to the left) with a front hub. Having a seat back might help. That's a very long bike. I notice they sell the bike with a mid-drive motor and even offer a Rohloff hub. I've had good luck with just a couple of gears for pedaling but a high enough gear is generally the problem.

Definitely an interesting bike and power pack.

View attachment 10361

The bike is 10" longer than a 'standard' 26" mountain bike.

I agree about the gearing.

I removed both shifters, The chainset can be manually shifted to a lower gear if the battery fails.

The rear freewheel is naturally locked to the highest gear without shifter tension.
I am switching it from 14 to 11 teeth for higher speed PA.
 

George S.

Well-Known Member
I've had good luck with the HK LiPos. The basic LiPo chargers are more programmable and give a lot more information. I never pushed the charge rate. The price is right and you can make the pack into a shape that works on your bike. I try to protect the packs. I stopped at around 4.10 v on the charge, and left something in the pack at the end. The packs I got were out of balance so it took a few balance charges to get them within .03 volts of each other.

I put XT60's on everything and have the connectors to put 2 in series and then parallel 2 sets of packs. Mine are 8AH and 5s.
 

Boyntonstu

New Member
Replaced freewheel with 11 tooth freewheel for higher speed PA.



The old one was dry and the ball bearings fell out. NO GREASE!

Went for a ride and there was still a lot of noise.

Obviously no grease on the other side bearing.

I sprayed Lithium grease onto rather than into the bearing and it helped.

It now runs quiet.

I will have to replace that bearing as well.
 

harryS

Well-Known Member
I also made my own torque arms. Just like in your pic, when first installed, I didn't have any thread left under the hold-down bolt. The holding force was in the notched area where the wire comes out. I was worried about it being weak.

I took out some of the washers in my kit, and used a thinner a spacer between the drop outs. Then the nut was on the fully threaded part of the axles. Just being anal.
 

Boyntonstu

New Member
I also made my own torque arms. Just like in your pic, when first installed, I didn't have any thread left under the hold-down bolt. The holding force was in the notched area where the wire comes out. I was worried about it being weak.

I took out some of the washers in my kit, and used a thinner a spacer between the drop outs. Then the nut was on the fully threaded part of the axles. Just being anal.

The wires come out the end of my axle and hence more threads.

Please share a photo of your arm.

What size is your motor and your battery voltage?
 
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