Fixing chainline for single speed - sprocket is way off

Hey guys.

I received a wheel with a motor that was supposed to be for single speed, but it seems that they just put a single sprocket on a hub designed for use with a cassette. The sprocket is sitting on very little treat already and way too far to the left. Since I have only a 2.25" wide tire the chain can just pass it but with no clearance. I want to use the middle chain ring of my Shimano Hollowtech II crank (Saint). This would be too far right.

Any ideas on how to align them?

I could gain 2mm by removing a washer of the bottom bracket moving both crank arms a little off center to the left, but I need much more..
Are there adapters for the sprocket?

Actually the motor design is not ideal. On the left side there is not enough space between disc and motor to fit my hydraulic brake caliper piston in and on the right side there is lots of space..

Thanks for your help!
Joe

It sounds like you got a wheel that was set up for 7 speed or more, and they simply threaded on a single speed freewheel.

The simplest and cheapest way to remedy your situation is probably to remove the single freewheel, install a 7 speed freewheel, and run the chain to the sprocket that yields the best chainline. There are some factors related to your specific bike that might make that a bad idea.

The fact that you have a Saint crank suggests that your bike was originally equipped with changeable gears. Why don't you want to use them?

Even before I got my motor I wanted to go single speed. Love the simplicity and clean look. I will probably do little pedaling from now on, just like support the motor on steep uphills or when accelerating from standstill. So far I ran the first 200km without a chain and I love it as an electric bike already. I also want to keep it looking like a functional bicycle.

I hated the wear of the narrow 9 speed chains and the regular maintenance and poor performance of the derailleur in serious off-road use (sand and mud) before.

I definitely want to go single speed now!