I'm fairly new to the bicycle world past knowing how to ride one, haha. I recently started using my older mongoose 21 speed this summer to get to work and around campus. I have found from personal experience and the internet that it is much more inefficient than a road bike so I have been trying to improve it without spending a lot of money since it mostly sees road. I inflated the tires more and adjusted the rear suspension to as stiff as I can get it. It improved a lot. I thought the other day about simply removing the rear shock / damper assembly and replacing it with a rigid metal link that I can machine at work. I'm thinking this will make a much rougher ride but more efficient bike on the road. Plus I can switch back and forth depending on what kind of riding I will be doing. The thing is that I'm no expert in bike design so I am wondering how altering the bike like this will change the stresses in the frame. Obviously a factory hard tail has different geometry than what mine would have. Just want to make sure it's not going to snap while im riding it, haha. Any thoughts? Thanks in advance.