I have a 2012 Specialized Expedition Sport Low Entry. The threaded top cap on the suspension fork is missing. The fork is a SR Suntour model number NEX-4110v2. I contacted Suntour, they told me the fork was discontinued and they didn't have parts for it anymore. I've checked with my local bike shops, but they didn't have anything. When I look inside I can see it's threaded. Does anyone know if I there is a safe substitute for it. I saw a few replacement caps but didn't know what size to try. Is it possible to make something?