If you have a fork with the star nut system, upgrade to this Gusset Unilock Headset Headlock system. 

'Headlock' type systems are great for replacing the Star System in threadless headsets.
Not only do they 'never slip', but they also add some extra security in case of a steerer failure.
Gusset UK developed a simple solution to the headache of solving which length Headlock system to buy.... They made a SET with 3 different length Cr-Mo bolts. (Just fit the one you need !)
Supplied as a set with Alloy Top cap and bottom T-nut to fit 1 1/8".
Features;
Laser etched Alloy top cap.
Light Alloy bottom T-nut.
3 lengths of XL Cr-Mo bolts...210mm, 235mm, 275mm.
Black anodised.
Weight; 110g (with steel lower)