How many links to remove going from 14-28t to 11-28t ?(front crank is 48t)

[gembike223]

I have a 7 speed folding fat ebike and it came with 48T crank + 14-28t rear. I changed the rear to 11-28t as it gives a much better cadence and "human power assist" for me.

HOWEVER, i notice I'm skipping chain alot when i'm on 11t , and i do see a good slack on the chain. Question is, how many links should I remove to shorten it?

ALSO, my flywheel seems to have abit of a wobble now that i switched out to the new 11t. it looks KINDA like this:
(this is not my bike, but it is like this. NOT to this extent but almost):

I didnt have a wobble before, what might be the issue...? I tighten the flywheel back quite well.. but maybe it's TOO tight, is there such a thing?

Thank you!

 

[indianajo]

Not watching a video. BIcycles do not come with flywheels. Find another expert.
If one sprocket of a cluster wobbles versus the axle, then the sprocket cluster is poorly assembled. Some of them have internal rivits that can allow the individual sprockets to be changed. These could get loose.
If the entire sprocket cluster wobbles on the axle, then the installer cross threaded it during the installation. Usually would require a new axle and sprocket cluster to correct a cross thread.
After changing the sprocket cluster to a smaller one, you pinch up the chain to wind up the takeup almost as far as possible on the largest sprocket. Then you remove that number of links that were in the pinched up part of the chain.

 

[Gionnirocket]

I think you mean Freewheel... Which is what you call the sprocket cluster at the rear tire.
As for the wobble... It may be your hub or the new Freewheel... These are entry grade parts and sometimes are not produced to the highest standards.
Are you certain that you screwed in on without crossing threads... They are fine threads and easily crossed. Also make sure it is fully seated... Which typically would happen on the first ride if you didn't do so during assembly.
If it's minor... I wouldn't worry as it is common and usually doesn't affect shifting unless extreme.
As for chain length I'd say you should be fine... But removing one link shouldn't be a problem. I've changed my rear similarly and the front from 46t to 44t without changing chain length.
But here's a tool to help you confirm
Or watch the Park Tool video for an explanation of how to measure your chain need.