Maybe, but probably not.  To check, the expansion nut for 7/8" steel bars is 5/8" at the widest point, the one for 1" steel bars is 3/4".  All Hollow-Tube fitments seem impossibly loose before tightening.  It is just an indirect result of our efforts to make a solid metal-on-metal connection that still fits as many bars as possible. The design of our hollow-tube fitments depends on two points of contact:  The expansion nut, which must be tightened and deformed forcefully against the inside of the bar, and the conical hilt of the nose, which is pulled against the inside lip of the handlebar in the last moments of tightening. It adds up to tightening it two times; once to deform the nut, then loosen a turn and press the assembly into the bars and wiggle it to make sure the hilt of the nose is seated, then tighten again.  At that point, there should be no play at all, in any direction, and it should stay put till you loosen it.

As long as the narrow part penetrates the bar, all's well.  The conical hilt of the nose will meet the inner lip of the bar at different depths depending on the inside diameter of the particular bar.  In the new Smooth City tm weight series, you can make up the difference with the internal shims supplied with the kit.  On the other hand, 2 1/2" of depth is required inside the bar to seat the assembly properly.  If there is something in there that is shallower than that, and it does not have screw threads, my stuff won't fit.  If it has screw threads 8mm or narrower, you are looking at the wrong weight now.  Call us 763-234-7242, and we'll get it sorted out.

You press the weight toward the ground in a bending motion, to jam the shims and nose up, till the nut gets tight enough to hold it all together.  Once you have tightened the nut up fully, and permanently deformed it against the inside of the bar, loosening it and pushing it in all the way and retightening it will be a breeze.  The trouble is all in the initial deformation of the nut.  If this doesn't work, check the threads of the nut for some kind of burr that impedes the screw, and remove the obstruction.  You might need to regrease the screw.

When you tighten it the first time, it expands.  A lot.  It doesn't spring back any more than is necessary to remove the weight.  It permanently deforms and molds itself to the inside of the bar.  I meant it to be this way.  Trust me.

You do things to increase your hand's traction on the weight.  Just make sure the thing you use doesn't have any dirt embedded in it, especially for Black and Chrome things.  Dish gloves, latex gloves, leather gloves, rubber bands, jar opening pads, etc. are good bets.  Also remember that on the initial tightening, you don't have to be fussy about where the weight is, as long as the nut is in the bar.  That way you can concentrate on holding the weight.  It is much easier on the final tightening, and you can then concentrate on seating it right.

You can't.  The threads are greased to ease installation, and using loctite instead would make it very difficult to remove this product.  It stays put, though, if you tighten it enough.

They may help, to varying degrees, depending on the application.  If this product hits the ground with the weight of the bike behind it, the screw will bend, and may break, compromising its protective value.  It may need spare parts after a tipover. But what it protects depends on what hits the ground before the handlebars, and whether the bars bend or not on impact.

Yes, usually.  Typically, the handgrip needs a hole cut in it.  It may need the whole end cut off.   This can typically be accomplished with a sharp pocketknife, and detailed instructions and photos are in the manual.