Just about to build a new bike up. Previously have used ‘fit and forget’ type forks with only air pressure and rebound to adjust.

The new ones (Sweep HLR) have high and low speed compression adjustment. What’s the best ballpark setup on these to begin with and what exactly (in simple terms) do they affect?

They change the way the fork responds to impact. The thing to remember is it’s the speed of the fork not the speed of the rider.

High speed is for the chattery type bumps and Low speed is for compressions and corners. More low speed will stop a bit of pedal bob and make your fork run higher out of corners. High speed may make you feel more through the bars and will make it harder to bottom out as you crank it up, might be useful if you’re particularly aggressive.

I’d do a bit of a search on Google and see what others are running, or read the manual and see what the suggested settings are for your weight and pressure. Failing that, start at half way and fiddle.

Change only one of them at once and ride a known section of trail then you’ll find out if you can feel the difference and what you prefer.