I used to have a handlebar bag on my road bike. It had a clear plastic cue sheet holder on top, which is why I bought it. Never noticed any problems with it. I suspect because it is close to the stem (and therefore the center of the handlebar) it has a minimal effect on handling.
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles