Mount the Components

The next component to go on the motorcycle was the motor controller.  The controller could have been fit into the empty gas tank, however it would have been harder to mount, harder to access, and I was afraid it might run hot.  So the best place to put it was underneath the seat.

I fashioned an upper bracket from 1/16 inch sheet metal, cut, bent, and drilled to fit.  It was bolted to the upper two mounting holes of the controller and to a re-purposed mounting tab on the bike.

bracket1 LR

The bracket was cut tall enough to keep spray from the rear tire away from the electrical connections, since the presence of the controller prevented a portion of the mudguard from being reinstalled.

bracket installed LR

The lower mounting bracket attached to one of the lower mounting holes on the controller and another unused attachment point on the frame.

Bracket2 LR

Later when the chain was installed, I discovered that it rubbed on the controller flange.

chain impact LR

The controller was removed and both the flange and bracket were trimmed to make clearance for the chain.

chain clearance LR

Next, the charger was mounted inside the left pannier.  The left pannier was chosen over the right so the weight of the charger would offset the weight of the motor, which was mounted to right of center.  Before mounting the charger, a hole was cut in the bottom of the pannier to fit a plastic grid which would allow vertical airflow for cooling of the charger.

Pannier1 LR

The plastic piece was a household soffit vent trimmed to fit.

Pannier2 LRThe soffit vent fit perfectly when pushed in.  I was planning to attach it with screws, but it was unnecessary.

Pannier3 LR

The charger was bolted to the inboard side of the left pannier.  It was positioned so that all the wires would be accessible and the lights would be visible.  Also, in this orientation the temperature sensor inside the charger is high inside the casing.  The result is a more conservative (earlier) cutback in charge when internal temperature is high.  Although this could result in increased charge time on hot days, it may prolong the life of the charger.

Pannier4 LR

A hole was drilled in the bottom of the pannier near the front, and a rubber grommet was installed so wires could enter and exit.

Next, the smaller components were mounted in the right tool box.  I could have put them in either toolbox, but a quick tally of weight asymmetry told me it was better to mount them on the right:

Charger:  11 lb x 9.5 in L = 104.5 in-lb L

Motor:  36 lb x 2.25 in R = 81 in-lb R
Lower battery stack:  42 lb x 0.25 in R = 10.5 in-lb R
Controller:  6 lb x 0.5 in R = 3 in-lb R

Net:  10 in-lb L,  plus the sprockets, chain and rear drum, which are also on the left side.  So it made sense to put the contactor (3 lb) and other stuff (1 lb) on the right.  It probably wouldn’t matter, but if you can choose, why not balance the motorcycle?

The components were laid out in the toolbox, then holes were drilled with a step bit and rubber grommets were fitted where the cables would go through.

Toolbox and step bit LR

Toolbox R LR

Then the components were mounted, mostly with bolts.  The lightweight relay was attached with command strips (adhesive foam).

Toolbox LR

In the left toolbox, I mounted the Analogger with command strips.

Toolbox L LR

The stock rear brake light switch remained in the left toolbox.  I later put the turn signal flasher relay in the left toolbox as well.

The throttle was slid onto and clamped to the right handlebar, and the matching left grip was pushed onto the left handlebar after the original was cut off.  The right handlebar needed a little filing and sanding on the end to get the throttle to fit on.


The left one went on quickly by pushing it partway, then smacking it several times on the end with my palm.


When it was on, it stuck like magic.  In the past I have used adhesive when replacing dirt bike grips, but it wasn’t needed at all here.


The Cycle Analyst was clamped onto the handlebars and the sensor and magnet were mounted on the front wheel.


The sensor was zip-tied to the brake cable.

Next:  Wire the Drive System