FJ ... XJR1300

[FJ_Hooligan]

Excellent point!

[RussTheEngineer]

Hi all, interesting subject, the rebound energy will indeed rebound but ONLY to the length that the shock will extend to, if the force is greater than that will allow, the shock will simply pull itself apart.  The weakest point from experience is either the top or bottom mount gives way and falls off  and that's nasty.   Just be careful, think what you are doing, ask loads of questions and go for it.
 

[Russfjr1]

Hi all, interesting subject, the rebound energy will indeed rebound but ONLY to the length that the shock will extend to, if the force is greater than that will allow, the shock will simply pull itself apart.  The weakest point from experience is either the top or bottom mount gives way and falls off  and that's nasty.   Just be careful, think what you are doing, ask loads of questions and go for it.
 

Sorry minor point it will actually push itself apart. But with the rider weight or weights on board this could be counteracted in favour of the twin shocks. .... will get back to you.

[Cobblesmacker]

Sounds like a big project. Don't forget all the equal and opposite force bits. The subframe isn't being supported, it's actually going to be supporting the weight of the riders and the bike. That's before you even think about the state of British roads and shock loading. If the shocks are angled correctly so that the cantilever in the subframe can transfer the stresses, then the weak points become the subframe mounting and the frame itself. A fun project indeed!