new stem & spacers issue
 

I bought a new stem that is not as tall as the older one. Do I need to buy more spacers or should I cut the steerer tube by a tad?
Also, what is the trick to get the play out of the head set?
I am struggling to get it right.

Thanks

I never cut a steerer unless I've found a permanent position and know I'll never need the additional length again. Even then I leave 5mm or so of wiggle room in case stufff changes in the future.

I remember back in the days of threaded forks, some people would trim their fork for a low profile headset, and be SOL if later they wanted a taller one like Campy or CK.

Add a spacer wither below or above the stem and leave your options open.

As far as adjustment goes, remember that any adjustment is impossible unless the stem/spacer stack is taller than the steerer by a few millimeters. Otherwise the top cap will beach out on the top of the steerer as you try to tighten the headset.

Here's how to adjust threaded headsets:

http://sheldonbrown.com/headsets.html#threadless

You likely have the "Aheadset" type. Remember that the stem binder bolts merely hold the adjustment set by the top cap bolt, they need to be loosened to make the adjustment them tightened to secure the stem.

even threaded headsets you can put a spacer between the top bearing race and the locknut..

You will need to either cut the steer tube or add a spacer. I'd go with the spacer option as its cheap and easy. You'll need the spacer to take the play out of the the system. Use the top cap bold to preload the bearings then tighten the bolts on your new stem to secure everything in place. If you are using a carbon steer tube, make sure that all the spacers are below the stem. I.E. no spacers on top of the stem. Hope this helps.

As a generality that's wrong. For almost all carbon steerer it's desirable to have the steerer extend slightly above the top of the stem and require a small spacer to obtain the adjustment gap. That assures the stem is completely surported by the steerer. The only exception I know about is Cannondale with their proprietary expander.