-
I have a 100mm stem on mine which is basically the same setup. Riding position is almost identical to my road bike with regards to drop and reach. Key issue is it does move the bars forwards which means they can encroach on your cargo space / kid's head / legs (if you have a rear facing seat on the front) etc etc.
In terms of handling, the stem doesn't play the same role on a long john as it does when it's directly
operatingabove the front wheel on a normal bike. It's difficult to explain, but if you take your hand off normal handlebars to signal, you keep leaning forwards on the bars with the other hand and the bike pushes back through the bars and continues on its path in a straight line. On a long john style, you kind of have to sit up a bit and slightly pull back rather than push, because it tries to pull out of your hand. It's because it has a very shallow head tube angle and your weight is in a different place on the bike. I haven't tried a short stem, but I'd wager it's actually easier to ride with a shorter one.
i don't really know much about frame geometry/angles and such, but is there a compelling reason why this bike comes with a very short stem? if i replaced it with something like 80mm, would is severely affect handling? could it be to stop you clonking your kids on the heaD?
i like the 'tech documentation' for the workcycles kr8.