Finally, this past week I was able to enjoy commuting in the eMR2 v2.0, equipped with a new single speed transmission, motor coupler and batteries, every day.
There’s still some mechanical work to do, such as address the howling rear wheel bearing and sticky CV joint, but all the EV conversion components are performing as designed.
Pictures and video coming soon, as well as a report from Power of DC happening tomorrow in Hagerstown.
A couple years ago when the eMR2 was still in the design stage, there were two competing coupler designs: a simple dual spline coupler (described in a previous post here) and a more complex design that incorporated the spring cushion hub from a stock MR2 clutch.
Incorporating the cushioned hub would insulate the splines for shock loads and provide a little misalignment tolerance. After the experience with the straight coupler these durability advantages, along with a provision to securely clamp the coupler to the shaft to prevent any axial movement, made the additional cost of the design justifiable.
The clutch hub was harvested from an ACT performance street clutch disc and cost about $90.
ACT Street Performance Clutch Disc
The rivets fastening the friction disk to the hub were carefully drilled out. The rivets also serve as spacers for the hub plates and can be seen at the bottom of this picture:
Dismantled Clutch Hub
Substitute spacers with the proper ID to fit the 1/4″-28 screws that replaced the rivets were easily sourced from McMaster-Carr. They can be seen between the screw and old spacer.
The yoke was machined by Robert at Artistic Machining and then sent to Form Tools to have the spline EDM’ed. A shaft collar was also incorporated into the design to nail the whole thing down.
All the parts were put together with red Loktite and installed just prior to bolting together the motor and transmission.
You would think a bike locked up to a utility pole at high noon on a sunny Sunday in the heart of Fells Point would stay still, yet this morning I found out otherwise.
Sometime in the thirty minutes in between glances outside “just to check,” I was dumbfounded to find my bike vanished while I was upstairs.
Someone must have snipped the cable and thrown the bike into the back of a truck since the Kryptonite U-Lock tied the rear wheel to the frame and prevented it being ridden away. It probably took less than 30 seconds all told, fast enough that it’s possible no one walked by during the heist. There must have some witnesses though, as this occurred across the street from a senior center and it seems there’s always someone looking out the window.
So, on the off chance that you see the bike below, drop me a line. I miss it.
![](https://turanga.com/wp-content/gallery/RfR2008/DSC00805.JPG.jpg "Penn Station, where you can pick up regional, Amtrak and light rail trains. To the right is \\"Male/Female\\", the bane of many an architecture enthusiast. I actually like the dissonance.")
