flw wrote:So do they help reduce strain on your back, shoulders or something totally different?
Yes.
flw wrote:How do you know what size rizer to try?
That's the tricky part. To find the right fit, you should measure your ideal sitting position from the triple tree. Then you need to familiarize yourself with the type of risers and bars, if you plan to change them also. Otherwise, just the risers.
The triple tree is angled, therefore, providing the risers to be angled as well. Since risers come in a variety of sizes, you have to consider the overall height (for straight risers), then viewing on a horizontal plane, determine the distance from the triple tree to the top of the risers. This will provide some input on pullback. If the risers have a bend, which are called pullback risers, then you measure from the tree to the farthest point of the risers, again, on a horizontal plane.
If risers along will not provide enough for your ideal position, then you may want to consider bars which offer more pullback.
When I changed my steering, I made mock setups using cardboard from the dimensions of risers I was interested in, until I found what I was searching for online. If you find something locally, retailers will usually allow you to take one risers and hold it to your bike if you ride up there with it. The same for handlebars. I bought my bars from an HD dealer who allowed me to look at several styles I had been interested in, then went for the kill.
Overall, it can take some time or you may find something fast and it works, but you just have to search.
Friends help you move. Real friends help you move bodies.