Measure the Thomson. My experience is they can be under sized and prone to slipping.
Annoyingly I leant my calipers to a friend and she’s kept them
Can you try with another seatpost?
@ghostface started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Measure the Thomson. My experience is they can be under sized and prone to slipping.