Fitting a curved end rubber watch strap

Thank you for reaching out and providing the details of your issue. It can indeed be tricky to fit a curved-end rubber watch strap at times, it might be a subtle alignment issue. Here are a few suggestions that might help:

• In some instances, you may need to slightly curve the spring bars to ensure a perfect fit https://www.watchgecko.com/products/pliers-for-curving-spring-bars
• Often compressing the spring bar slightly more than usual can provide the extra give needed to align with the lug holes.
• If the rubber material is stiff, gently warming it up in warm water can increase flexibility, making it easier to manipulate into place.

If you continue to have difficulty, a local jeweller or watchmaker/repairer often has the tools and expertise to fit the strap securely without risking damage to your watch.