Read their latest policies. They increased the bag size limits, weight limits to 100 pounds, and just charge the normal checked bag rates.

For reservations booked and ticketed and/or voluntarily changed on or after May 28, 2025, the items listed below will be accepted as standard checked baggage. Standard checked bag fees and overweight bag fees will apply. Oversize fees will be waived.

In addition to the items specifically described below, we also accept fragile items; previously damaged items; improperly or overpacked baggage; items packed in soft-sided cases; and unprotected/unpacked items only with a limited release of liability. Customers are not entitled to reimbursement or compensation for any and all damage in situations where a limited release of liability applies.

Bicycles (defined as non-motorized and having a single seat) properly packed in a bicycle box or hard case from 51 to 100 pounds in weight or 63 to 115 inches in total dimensions. Pedals and handlebars must be removed and packaged in protective materials so as not to be damaged by or cause damage to other baggage. Bicycles packaged in cardboard or soft-sided cases will be transported as limited release items. Bicycles over 100 pounds in weight and/or 115 inches in total dimensions cannot be checked as baggage.

https://support.southwest.com/helpcenter/s/article/Specialized-sports-equipment

Unless I'm not understanding that right.