Mammoth has retrofit safety bars on most of its older fixed grip chairs over the past decade. The sole exception is chair 25, a triple where I've read that an added bar would make the lift too heavy. Given its height off the ground there were lots of comments when chair 23 did not have a bar.
Telluride retrofitted a 1980s Chair 9 Triple with safety bars and later footrests in the 2000s. Due to the additional weight, chairlifts had to be removed, resulting in a degraded capacity from the theoretical triple chair of 1,800 skiers per hour to a double chair capacity of 1,200 skiers per hour.
I don't think most resorts are willing to do something like this. Frankly, I do not know how you retrofit Riblet center pole lifts. Stowe's old Bir Spruce/Spruce Peak double was a center pole chair with safety bars that rotated horizontally to close. Strange. I think MRG's single chair does this as well.
What's interesting to me are some changing attitudes towards lift infrastructure:
- Brits tend to dismiss any lift or resort that is not high-speed.
- Germans will rank S3 Super Gondolas on speed and smoothness
- Millennials-to-Gen Zers (PeakRankings writers) seemed shocked when a Western US Resort lift did not have a safety restraint, which decreases their score.
Many expectations around restraints on modern lifts.
And I expect it too on major lifts. However, I do not mind no-bar lifts that serve shorter terrain, such as Alpental's top lift, Crystal's High Campbell, 7th Heaven at Stevens, and some lifts at Squaw, etc.
I also wear a pack (small avy day pack/20+L's) that pushes me forward, so I will put down bars on HS lifts - especially if there is a sudden stop.