Update on my Brompton. 100mm bar grips didn’t work at all. I had to shorten JC handlebar as I had a riser which allowed only narrower handlebar to fold it down. I removed the riser on my H stem and installed new JC handlebar which is full 60cm. This allowed me to use both 130mm grips and innerbars. 60cm handlebar improved handling significantly and innerbars provided more sporty grips and good alternative to the grips. Very happy with this setup.