-
I'm not sure i really understand the question, you want to ride an bike that's uncomfortable, so that you can ride a bike that's uncomfortable?
With flatbars you'll generally need a longer stem to replicate a more "road" postion with drops, but then the wider the bars will bring your body lower so might need a short/higher stem.
A short stem will make the bike feel "lively"
Basically it will just be trail and error with making the bike comfortable and fun, but making your bike more uncomfortable will do nothing to improve your flexibility and will make it worse if you're not doing stuff off the bike.
Apologies if it's already been discussed here but what's the consensus on wide bars and 110m+ stems? I've really taken to risers lately but i'm worried being upright all the time is going to stunt my already shit flexibility. I was thinking of using a longer stem to stretch me out a little as on a road bike i'm normally using a 90/100mm stem resting on the hoods. My Capo has a road rake fork so is fairly calm up front, without having a longer stem to try i'm a little concerned 110mm+ with 680 bars will be a little boat like.