This is my Gilles Berthoud.
Just recently completed the overhaul.
The bike has Vitus Rocky cromo special double butted tubes. It had a complete XT 732 group, according date code from 1989 incl. headset, seatpost, seatpost clamp, sharkfin, pedals etc.
Just the crank was replaced by crap and it came with polished brakes. I've used a black crank and brakes and also re-pro decals in all black to get a bit of a reduced color scheme. Tires are new and it's a much better ride compared to old Panaracer Skinwalls I've tried too.
The stem and bar had been from Philippe and surprisingly light. As it's a bit small or short for me, I've used a similar looking but longer ITM stem instead.
Gilles Berthoud Mountain Bikes seem to be really rare. The funny thing is that i had a few years ago for a while an exact same model.
Just the frame size was too large for me.
There is very little documentation about Berthoud Mountain Bikes / VTTs.
I found some line up for 1990 and 91:
and snippets of a catalog or brochure (most likely also ~1991?)
If this was similar also for 1989, mine should be a Nepal or GB Competition then?