Andrew R Stewart 

I expected that John would chime in on this thread. We have both used many Stronglight roller bearing headsets but have rather different opinions.

If you have plastic head tube cups/cones then you have the lower cost version, uses the same rollers and conical contact surfaces. After 6+ on personal bikes and many more installed for customers I find they have some differences from balled headsets that bare notice.

First is the lack on open interior volume. What? Well this speaks to how much grease one can trap inside the headset. Less space is less grease. less grease is less "oil" (remember bearings quickly plow a trough through grease and push most all aside, from then on then the oil in the grease feeds the bearings). I found, unlike John's experience, that these headsets likes more frequent servicing.

next up is the adjustment. The many parts inside the headsets make for a lot of possible slop/movement. While I hate stiff turning headsets I ran these with a bit more preload then I would with a balled design. I also found that I usually went back to a recently serviced unit and increased the preload after initial use.

Last on my list is the tall stack height. A couple of MMs more then a Campy NR/SR. So when retrofitting a Stronglight roller bearing unit to an existing bike care needs to be taken in the prior to purchase measurements. When the top/lock nut doesn't have many threads of engagement it can strip, a steel nut was a common upgrade on customer installs.

At one time the bearings were available as a kit independent of the complete unit. The 4 conical contact surfaces and two plastic retainered roller elements. Every so often these can be had on E bay. The NIB (as in "bag") A9 I have on my shelf waits for the right project. Andy