This is not a normal Enfield problem, but it is a motorcycle issue that is relatively easily corrected. With age and use most spoked rims will need attention. First check your wheel bearings. Bad bearings will cause quite a wobble. Tape a pencil to the forks so that the point almost touches the rim. Chock up the bike so you can spin the wheel. You will be able to tell if the rim is out of true by watching the point. Some run out from side to side and/or up and down is normal. It takes a LOT of run out for the average rider will notice your symptoms. If it is out of true, take it to a qualified mechanic for truing. It is not as easy as it looks to adjust spokes. Other problems are more likely. Most wobble or shake problems are the tire. Check the pressure! This usually fixes the problem. A worn or old tire can be the culprit. And of course the wheel assembly should be balanced. All this presumes that you didn't hit a curb.Ggood luck!