Gilles Variobars.

How do you get the cunting handlebar tubes out of the risers? I don't
want to use the risers, just the clip-on bits.

Photos of them in component form here:

http://www.apexleisure.co.uk/gillesvariobars.htm

 

In uk.rec.motorcycles, Lozzo belched forth and ejected the following:

Angle Grinder

 

"Lots of heat and plus gas"
"'it it wiv an 'ammer"