I recently upgraded my wheels to Zipp 404 and they're great, the problem is I can't pump the tires up with my pumps. I have valve extenders and the valves are open but when I pump I can't force the pump down because it has built up pressure. Fact is I can't get air into the darn tubular. Should I upgrade my pump..again? I can dump CO2s into it but that's just not how I want to do it. Any suggestions would be appreciated, or tips or tricks would be helpful. I've got this super nice wheelset but I can't ride the darn things. I've been told to reglue the wheels and use teflon tape so the air won't escape but that's another high cost.