Regarding bearings, courtesy of Weight Weenies:
X1 & X2.
Zero Ti, Stainless & Chromoly.
Light Action Ti & Stainless.
X5 (aka X3) and Light Action Chromoly are completely different inside and not compatible with the other pedals listed above.
To do a full rebuild requires the following items which can be found at any bearing/hardware supply company:
2 each – HK1010 Needle Bearings. Measurements: OD=14mm BORE=10mm WIDTH=10mm.
2 each – Bearing 136 also known as 686z, 686zz, 686 z, 686 zz. Measurements: OD=13mm BORE=6mm WIDTH=5mm
2 each – Bearing 137 also known as 137z, 137zz, mr137, mr137z, mr137zz, mr 137, mr 137 z, mr 137 zz. Measurements: OD=13mm BORE=7mm WIDTH =4mm
2 each – Inner Retaining Ring BORE=1/2″ WIDTH=0.03″
2 each – Rubber O-Ring. ID=5/16″ OD=7/16″ WIDTH=1/16″