XT660R Everything standard. When I ride on gravel with a bit of loose sand in patches it feels as if the bike wants to slip. All I can manage is about 40km/H or so. Anything faster and it feels as if I am going to fall. Wierdest of all is it feels as if the front wheel is slipping out. The back is solid. Anybody got an idea? Tyre treads are still fine

Tyre pressure?..tyre profile?...I have Avon trailriders on my R,they are excellent on the road but have little traction on sand/gravel etc..

how deep is the gravel layer? is there some hardpack right underneath it?

Yes there is hard ground underneath the loose sand. The sand would be anything from 3 to 5cm deep with hard clay soil underneath. Between these areas it is fine. Doesn't seem to like the corrugations much either. I have noticed though that if I lean back so that there is more weight over the back wheel the bike is a bit more stable but not by much. I am sure that if large stretches of road where covered in loos sand I would get used to it, but there are just these small patches of about 2 to 3 meters long. You don't see them until you are in the sand and then the steering starts to get veeeery loose.

then don't lean over on the patches with sand/gravel.
stand up and grab the bike between the knees.
if it's that bad, maybe lower the rear suspension somewhat with less preload?
might be your bike is loaded too much up front.
for mx in deep sand,i also need to lower the rear (or up the front) to get more stability.
see how this helps out.

I am sure the bike is not setup correctly for my weight. I will definitely study up on that and see what I can do. Thanks for the help