@steve_sordy - that's the wheel swap dead in the water then, unfortunately. The cassette incompatibility is the dealbreaker. Your Vala runs SRAM Eagle T-Type Transmission - that XS-1275 cassette requires an XD driver body on the freehub. The Merida's EP8 wheel will have a Shimano Micro Spline freehub (for the XT cassette), and you simply can't mount an SRAM XD cassette onto it. Different spline pattern entirely, no adapter exists.
So the checklist now reads: • Hub width / axle - you've confirmed these match ✓
• Bosch rim magnet - transferable, minor job ✓ • Cassette -
hard stop. SRAM XD vs Shimano Micro Spline freehub. Not compatible.
Your options before Sunday:
1. Source a replacement wheel with an XD driver - a long shot at short notice, but worth a ring round local shops today. A spare rear wheel with an XD freehub would let you run your existing cassette.
2. Swap the freehub body on the Merida wheel - if it's a Hope, DT Swiss or similar hub with swappable drivers, an XD driver body might be available same-day from a well-stocked shop. Worth checking what hub the Merida is actually running.
3. Honest fallback - is there a bike hire option at or near Sherwood Pines if the wheel situation can't be resolved in time?
What hub is on the Merida wheel?