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Think the current market will see a few teams disappear along with the new fees/legislation. Take a look at companies house…

Could be the clutch in the mech is creating too much resistance and causing the chain to kick back. Try adjusting the clutch or having it off. Obvious one is gear cable could be badly routed/kinked check both inner and outer for tight spots by cycling the suspension without a shock. Other than that freehub internals would be most obvious...