Let’s address this methodically. You don’t give us many clues except that the wheel keeps jamming, and you think it’s the bearings.
Lift the uni, or turn it upside down and rest it on its seat.
Now, spin the wheel by hand and let go.
Look where it stops.
Is the tyre touching the frame? If so, then that is at least part of your problem.
Is it because the wheel is buckled? This means that the tyre will only catch the frame at one point in the rotation of the wheel. As you spin the wheel, you will see the tyre appears to weave from side to side. This is because the rim is distorted or buckled to one side. Cure: remove the wheel, remove the tyre, tube and rim tape. Get the wheel trued. That’s a fiddly job, and unless you are 100% sure, get the local cycle shop to do it for you.
Is the tyre too fat for the frame? If you have a wide tyre in a fairly tight frame, it could be that the amount of buckle on the wheel is very slight, but enough to cause the problem. Cure: as above, or put a narrower tyre on!
Is the frame twisted or bent? This could cause the tyre to catch the frame. Check by eye. Measure equivalent distances each side of the frame. If the wheel is constantly leaning one way in the frame, rather than wobbling from side to side, then it could be a damaged frame. Cure: applied brute force and ignorance, or a new frame.
If it isn’t the tyre catching the frame, then it must be something else.
Long shot: is the crank catching the frame? A nasty UPD could bend the crank in slightly. Cure: new cranks. ALWAYS use the proper crank tool. About £10, $15 from any bicycle shop.
Are the bearings too tight? This one seems likely. On most unicycles, the bearing is held onto the bottom of the fork by a C shaped piece of metal, with two bolts. (main cap bearing holders.) It is an easy mistake to do these up too tightly. Slacken them off. (usually 10mm or 11mm spanner) and spin the wheel again.
The correct tightness is this: ticghten them by hand until they sit firmly in place(won’t wobble under gentle hand pressure) then ‘nip’ them a bit tighter with about 1/4 turn of the nut.
If they are too tight, the C shaped pieces of metal will grip the bearings too tight and bend them from round to oval.
If the bearings are permanently damaged then you will need to replace them. This is not a job I’ve done, but I think you’ll need circlip pliers and a bearing puller. If this sounds greek to you (and you don’t speak Greek0 then go to a local bike shop.
Could it be that the bearing holders are too loose? If so, then conceivably, the bearings could be slipping out of line somehow and jamming intermittently.
Could it be that the bearings are full of grit and sand? They are quite vulnerable. You COULD try flushing them through with light oil/WD40 and seeing if they free up. if not, then either (A) strip and clean them (a big job, and possibly not worth the effort) or (B) replace them, via unicycle.uk.com / unicycle.com , and perhaps ask the local bike shop to fit them.
So, approach methodically, from the outside of the tyre in (more or less) towards the hub:
Tyre too big? Get narrower tyre.
Rim buckled? Get it straightened.
Crank bent? Get a new pair.
Frame bent? Straighten or replace.
Bearings too tight/too loose/contaminated? Adjust, flush, replace.
Failing that, ask again.
Good luck.
heh ehh ehh well ok, thanks again!