My Townie Commute Go has an annoying problem.

[Katman4532]

I have a new bike (under warranty) with an odd "glitch." I just need an idea what I'm dealing with.
Whenever I've shifted into 5th gear with the assist on, after a quarter to a half mile the crank acts like it
has jumped a chain link. It may happen several times while riding. Now for the odd part. I rode over a mile
in fifth gear with the assist off, and nothing happened. In fact, with the assist off it behaves completely normal. This problem only seems to happen in fifth gear with the assist on. All the other gears are fine. Any ideas? Thanks!

 

[indianajo]

Higher sprockets are the ones that tend to skip under higher torques. This is true on pedal only bikes, too. I suppose this is a mid drive motor that acts on the chain? That would give you higher torque when the motor was assisting.
You may be able to adjust the derailleur tighter to eliminate this. Loosen the axle nuts, also any derailleur screw, and pull against the spring tension to increase it, then tighten the axle nut. Easier said than done. I use a channl-lock pliers to do the tightening. I would find this job easier than taking the bike to the shop for warrentee work.
If this doesn't help look at the fifth sprocket teeth. When I wore out a sprocket and it started skipping, the teeth tips were noticeably rounded.
Your bike may have a used chain or gear cluster even though you bought it "new". It is worth looking at it.

 

[Trail Cruiser]

You ebike is still under warranty, you should have it fixed at the LBS where you purchased it. A new ebike is a significant investment and should be trouble free when new.

 

[ForlornMTL]

I have a new bike (under warranty) with an odd "glitch." I just need an idea what I'm dealing with.
Whenever I've shifted into 5th gear with the assist on, after a quarter to a half mile the crank acts like it
has jumped a chain link. It may happen several times while riding. Now for the odd part. I rode over a mile
in fifth gear with the assist off, and nothing happened. In fact, with the assist off it behaves completely normal. This problem only seems to happen in fifth gear with the assist on. All the other gears are fine. Any ideas? Thanks!

I had the same issue with my Townie Commute Go. Got it less than a week ago.
Found a video that explains it clearly. It's something that happens on a brand new bicycle. Cables get "stretched" or settled into place.
It's an easy fix that does not need any tools at all. I would call it an adjustment.
Also, all bolts need to be checked after the first week or two of use. As vibrations could loosen things up.

 

[Solarbuddy]

Thanks for that video! I have a Nexus hub on my Dahon folder and this fixed that annoying mid-range shifter issue.