AriGold - if by "damper" you mean rear shock, ignore this post.
I looked at the Ohlins
steering dampers for a custom install awhile back and
found this link to the Owners Manual which might be helpful.
On page 6 you will find the stroke specs for all of the 'generic' models, with the model numbers listed. By 'generic models' I mean those that use a clamp around the damper body on the frame-end which is adjustable for location along the damper body. Ohlins also makes many bike-specific models which have the frame-end mount cast to the body so that is non-adjustable for location (note that some bike-specific models also have a wire for connection to the bikes electrical system eg late suzuki GSX...). According to my source (an Ohlins retailer in the USA) the damping characteristics of all of the 'generic models' are essentially the same.
Pages 4-5 give examples of side frame mounting ('the purse snatcher mount') and the cross-frame mount above the triple. Page 7 lists the fork-leg clamps available from Ohlins, though there are other sources for those. Obviously you can fab your own frame-end mount if you are unable to find a pre-fab piece for your application. Here's a link to
the Motowheels page that offers nifty mounts for some Ducs.
It is easy enough to use a rule to measure the min and max distance between the 'frame mount point' and the 'fork mount point' that you envision for your application. You need the damper stroke to be slightly longer than the (max minus min) distance so the damper does not act as a steering stop.
Hope this helps, have fun with your project!
