A number of Intense models make use of four 6901 bearings in the upper linkage - some frames use 6901 bearings in the seastay as well as the top link, while others only use these bearings in the seatstay.
The following frames require FOUR 6901 bearings - two in the seatstay and two in the top link:
Tazer VP (All model years)
Tracer 275 (2014)
The following frames only use TWO 6901 bearings, located in the seatstay (the top links on these bikes use 6802 bearings, sold separately):
Tracer 275 (2015+ alloy &; carbon)