This is my second electric trike and an improvement over my first effort which can be seen here
The new trike features full suspension, rear pedal, a 1000w hub motor, disk brake (rear) and even cruise control. The basic frame construction is quite similar to the steps shown in my previous Instructables and will not be repeated here. This Instructable will concentrate instead on fabrication details unique to this particular build that might be of some help to other builders.
I purchase my 48V, 1000W hub motor kit from Yescom USA/xcceries via Ebay. The kit included the wheel, tire, hub motor, controller, brake levers with electrical cut-outs, a disk brake disk (no caliper), cloth battery case for 4 12V batteries, thumb throttle, battery mounting rack, cruise control module, and all required wiring except battery jumpers to configure whatever battery system you decide to use. The kit, including shipping, was $228.76. I was VERY pleased with the kit and the responsiveness of Yescom/xcceries when it was discovered one minor part had not been included with the original shipment. I’ve put over 500 miles on the trike since completion and the hub motor has run flawlessly.
Other costs (all include shipping and taxes):
4 12v/18ah SLA batteries from Titan for $145
3 KMC Z51 drive chains for $31
generic ATV disc brake caliper $9
2 QSC 3/8" rod ends for $6.30
Shimano shifters and cables $29
2 pillow block ½" bearings $21
10 shaft collars $10.55
2 Craftsman tractor seat springs $4
Set of Bell brake cables $11
Misc steel for frame and brackets $80
Flea market bikes $15
With a few other misc. nuts and bolts the total cost of the trike was $600.
Step 1: Bottom Bracket and Front Derilleur
A Giant brand flea market bike was cut apart to salvage the bottom bracket and derailleur post. The BB was welded to a section of 1.5 x1.5 tubing and then 3/16" flat stock was used to make a bracket which can be slid forward and back on the frame to accommodate drivers with different leg lengths.
Step 2: Frame and Drop Outs
The frame is constructed frame 1.5 x1.5 rectangular tubing. The rear drop outs are made from 3/16" flat stock. The hub motor wheel has a 15mm axle so drop outs are drilled at 15mm and slots cut out to allow wheel to drop out. The non-drive rear wheel has a quick release tightening mechanism and special drop outs must be made to allow the quick release to fit. A 7/8" ID/ 2" OD washer is used to make this mount. Cut an opening in the washer then clamp the dropouts and wheel together with the quick release centered in the washers. Remove the clamped assembly and weld the washers to the drop outs.
Step 3: Seat and Suspension
The front suspension is a Duo Track 7001 front fork suspension which came standard with the Giant brand flea market bike I used for the project. Not a great fork suspension by any means but will due until I locate a better one at the flea market. The rear is suspended by placing garden tractor seat springs under the rear of the seat and hinges at the front of the seat. This works surprisingly well given the cost ($8 for the springs and hinges) and provides a far more comfortable ride than the solid mounted seat on my first trike.
Step 4: Remote Steering
The trike is steered remotely by mounting a set of handle bars just in front of the seat and using a tie rod to connect to the stem of the front fork. The remote steering tube was cut off a junk front fork (Photo 1). A seat post is welded to the bottom of the steering tube. The smaller tapered end of the post should slip into the steering tube once any excess weld and debris is ground away (Photo 2). I used the head tube from the same junk bike. A length of 1.5 x1.5 square tube is cut in half lengthwise and then the two halves are welded to the head tube. You can just make out the seam of the two halves in Photo 3.
The head tube is welded to an upright on the frame and the steering tube is inserted upside down in the head tube with the seat post extension pointing up (Photo 4). A steering arm is cut from flat stock (Photo 5) and welded to the steering tube (Photo 6). At the front fork a slip tube is cut from ½" black pipe with an angle cut in the bottom end to match a stock “tightening head” and bolt (Photo 7). The “L” shaped steering arm shown in the photo was later cut off to form a straight arm which is shown in the finished assembly (Photo 8) This arm is welded to the top end of the black pipe slip tube (Photo 9).
Step 5: Steering Tie Rod
The tie rod connecting the remote steering to the front fork is made using ½" conduit. Six small holes are drilled around the end of the conduit and a 3/8" fine thread nut is slipped into the end of the conduit (Photo 1). The nut is then blind welded to the conduit through the six small holes. Be sure to insert a bolt into the nut while welding to prevent slag from getting on the treads (Photo 2). Photo 3 shows the inner nut welded in place and then a rod end and jamb nut attached. The finished tie rod is shown in Photo 4 and installed in Photo 5.
Step 6: Jack Shaft, Sprockets and Chain
A jack shaft is used to transfer the center mounted pedal power to the outer right rear wheel. This is also the hub motor drive wheel which comes with a 7 cog sprocket set installed. The jack shaft is made using two ½” ID pillow block bearings mounted to the frame. A 12" long ½" bolt is used as the drive shaft and pedal sprockets from two junk 20" bikes are used on each end of the drive shaft. The chain from the front derailleur to the jack shaft changes length as the front gears are shifted. An old derailleur was used to keep tension on the chain and eliminate slack due to the gear changes.
Step 7: Disk Brakes and Rear Derailleur
The Hub Motor kit comes with a disk brake disk but not a caliper. I used a generic ATV caliper and mounted it using a bracket made from flat stock (see arrow Photo 1). The rear derailleur would not line up properly when mounted to the axle of the hub motor. A small bracket was welded just behind the drop-out and the derailleur is bolted to the bracket (Photo 2).