Why are lo pros good to ride round london?

longer stem?

I'm always telling people who either have or complain of back trouble that the answer is not to raise the bars and make them closer, as this puts the weight on the base of the spine and bends the back instead of pivoting from the hips.

whacking risers on an otherwise correctly set up track bike will do that straight away, and coupled with the usually too-high saddle that I see people having that's a back problem waiting to happen. It might feel good for short runs in town, but it won't do any long term good.

Exactly....which is why the lo-pros are helping.
My brooklyn currently has a 100mm stem and risers on....after riding the lo-pros for a couple of weeks i went back to the brooklyn when i took it to scotland last week and it felt horrible.....so upright and layed back....took me ages to adjust.
So i'm gonna try a longer stem and see how it feels.