Northwind – You can’t have your cake and eat it as it were. The weight on a bike is going to be rear end biased, the rear shock has to deal with more energy than the forks.
You can play with leverage ratios all you want, but for the rear suspension has to always deal with the same amount of net energy put into it from an equivalent impact.
If we consider the scenerio as energy dispersed per unit length of shock shaft displacement.
Normally shorter travel=shorter shock stroke. So a shorter travel bike normally has to disperse more net energy per unit length than a typical longer travel bike. To disperse this net energy, either the spring stiffness needs to be increased and/or damping coefficient increased, this results in a harsher ride.
So how can a shorter travel bike (assuming shock stroke is shorter than the longer travel counterpart) be designed to feel supple and bottomless, manipulation of leverage ratios. High leverage ratio feels “supple”, they input more energy per unit displacemt, low leverage ratio feels “harsh”, they input less energy per unit displacement.
What i’m trying to say is a shorter travel bike, assuming it has a shorter shock stroke, no matter how much the suspension design is manipulated, has to have a greater region of low leverage, hence a greater region of harsh feeling suspension than a longer travel bike.
For myself to suppose properly, shock stroke and leverage ratio curve would have to be known.
So everyone’s ramblings, including mine aren’t really valid until we know for certain the specifics of the suspension design.
I agree that there does need to be shorter travel bikes with more stable geometry.
I just think expecting 100mm of travel to deal with the same impacts as the 140mm travel up front in a manner that doesn’t feel harsh at any point is quite unreasonable and much.