It's a common issue. There's not much more advice to give than to train for what you'll be climbing. If the topo says ringlocks, but it feels more like tips, then you just have to train by climbing tips. Find a gym with an adjustable crack wall, or build one yourself and train, train, train. System boards at the gym are also helpful to focus your training on specific techniques and holds.

One bit I can share about getting big feet into thin cracks is to use the sole-to-rand surface of the outside of your foot to create a friction jam against the crack(think pinky toe edge against the crack with toes pointed up) and look for any pods or scars that you can use to get a bit more of your foot in for more security.

Vary the routes on your trip, thin for wide. No reason you should be the only one who has to suffer- just find some slightly wider cracks that are perfect hands for you!

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