the dummy is stiff
in fact any flex comes from the V-racks
if you are using a suspension fork
then you add a FreeRadical
the suspension will need to have the pre-load increased.
nominally speaking: typical bicycles have about 30% of the weight on the front wheel, while 70% is on the back.
on a long tail cargo bike, its more like 50/50
so when you add an XtraCycle to a MTB with a suspension fork, the pre-load will need to be increased.
see Surly Spew #19
"One thing you need to consider before putting a suspension fork on your long bike is that your body weight is more centered between the front and rear wheels than on a standard-length bike. This effectively takes some weight off the rear wheel and puts it onto the front wheel. So if you weigh 180 lbs (82kg), a suspension fork on a standard bike registers approximately 56 lbs (25kg) of your total weight. Meanwhile, a suspension fork on a Big Dummy would register approximately 90 lbs (41kg), or half your total body weight. So you’ll need a suspension fork on which you can significantly increase the spring compression to compensate for the effective weight addition. Otherwise you’ll probably be bottoming out the fork and/or it’ll feel like you’re riding something very saggy."
i've been using my Dummy for over a year now.
there is no comparison to a convert job.
while a convert job will give you an idea of what can be done
it will also highlight little things that you may want remedied
maybe you won't even notice.
there are plenty of people out there on XtraCycles
I used a Cannondale for my convert job, and used it for about 2yrs.
immediately, i knew what i did not like.
however, it is a viable option.
the FreeRadical holds resale value
and the rest of the kit goes onto a Dummy, if that times comes around.
which is exactly what occurred with me.