Question re: Cutting back old spikes while a new one is growing

[NytroJen]

Hello from Rhinebeck, NY (about an hour and a half north of NYC, straight up the Hudson River).

I'm pretty new and I have a question. My orchid has two old spikes. I never cut them back because they still looked fairly green and alive. But now there is a new spike growing, and I want it to get all the energy it can. Is it okay to cut the old spikes now, while the new one is growing, or will it upset the whole plant too much?

Thank you so much! I have been trying to grow orchids for many years and I've never been successful (hot, dry apartment). Finally I have two that seem happy and healthy and I want to keep them that way.