What the traveller is balancing
The traveller controls yarn tension during winding, and its weight is the main lever. Too light and the yarn balloons and tension falls; too heavy and tension rises with more end-breaks and more heat at the ring. The right choice sits between two failure modes rather than at a maximum.
The variables that move the answer
Yarn count and fibre type. Spindle speed. Ring diameter and its condition. The profile of the traveller itself and its clearance over the ring flange. Ambient conditions in the spinning room. A change in any of these — new yarn count, a speed increase, a re-ringed frame — is a reason to revisit the selection rather than to reorder what was used last time.
Ring and traveller wear together
Travellers and rings are a running pair. A worn ring will consume travellers faster and give inconsistent tension regardless of the traveller chosen, so persistent traveller problems after a correct selection are usually a ring question. Tell us the ring condition and age along with the yarn details and we will work through it with you rather than simply quoting a number.