my xr has always been a bit shaky at speed bc i have a big front fender and non DOT knobbies w/no damper and ride pretty often on the freeways in la. but ive gotten pretty used to the speed wobble and plan on switching over to some more road friendly equipment soon. but the other day i went over a rough patch where an old railroad used to be, a section which i go over every day on the way to work and usually stand up and take it fast and fun bc thats the beauty of riding an xr in the city. but today on the way home from work my front end just went nuts at about 45mph and my front end was just bouncing back and forth and nearly buckled and i surely felt i was going over the handlebars but somehow managed to straighten out and continue home. ive ridden over it a few times since and it just seems like my front end is more wobbly all the sudden out of nowhere. any thoughts on what this could be? much appreciated..