My brother has a 1986 Yamaha TY350. The rear tire has been on the bike since he purchased it and was overdue for a change. I started a tire change last night and found that it had two rim locks. The TY350 came with tube-type tires and has a traditional tube-type rim. Are the rim locks necessary? Maybe just one? When I bought my Scorpa, it had a tube installed with no rim locks. I rode it for several months that way without issue. Thanks!