Is my mountain bike too small for me?

[Maurizio]

I have a diamondback coil ex that is a 16 inch frame, and I am 5 foot 10 inches, is it too small?

 

[Cody]

if you feel comfortable riding it then you should be alright

 

[bob a]

Yes, you need a 18 or 19 inch frame.

 

[Carl_the_Truth]

If you can adjust the saddle so your leg is just slightly bent at the 6 o'clock down stroke, you're fine.