So I bought some bars off of Ebay-16" Bare Knuckle Choppers Mullet Ape Hangers. The bars are from http://bareknucklechoppers.com/bars.html .... I got them in the mail and the part of the bars, where they clamps down to my risers is not nurreled (I dont know if that is the correct spelling) . My current 16" are not "nurreled" either, and they move on me if I hit a bump to hard. I was wondering if anybody new how to make the grooves without teh bars losing any integrity.

Thanks for the help!

 

First question, is the inside diameter of the risers too large to tighten down correctly on the outside diameter of the bars? Do the risers have any gap left between the top and bottom pieces when you tighten them onto the bars? If they do your good with just roughing the mounting surfaces up. If your risers are clamping down as far as they can already you have a different problem and none of the suggestions below will help because knurling, scoring, or cross hatching will not solve the issue because the bars will still not be a large enough outer diameter for the risers to firmly clamp down on. If there is some gap left between the top and bottom risers with the bolts tightened all the way and the surfaces are just too smooth to keep the bars from spinning then one of these options should take care of it.


You can call around to the local machine shops and ask if they have a hand knurling tool and what they would charge you. The cool shops wouldn't charge for such a small task but a lot of shops would try and hit you with an hours labor. You could also consider buying a hand knurling tool but they are fairly expensive for something your not likely to have a need for again for a very long time cause specialty tools are not usually cheap. Depending on resources of where you live you might find a rental tool shop that has one but rental tool shops are getting pretty scarce.

You could rough up the part of the bars and risers that meet. With the bars mounted put painters tape over the parts you don't want messed up, remove the bars and sand the non taped area down with very course sandpaper, same with the inside of the risers.

You can use vise grips and create knurls on the bars same with putting them in a bench vise if it has a set of nice cross hatched grip blocks just make sure you don't badly warp the diameter of the bars when your doing that as your only trying to create some rough surface not reshape them.

If you have a dremel or similar hand tool you can just make some scoring on the bars yourself and like sanding them just put painters tape where you don't want to score so you know where not to mark up. The cutting wheels work nice for this if you can keep a light touch.

Its not hard to knurl, cross hatch, or score the bars just remember keep a light touch with power tools as you only need to create a rough surface for the risers and bars to tightly grip not cut a hole in them or saw them in half.