Hi, I have a Specialized Allez with Tiagra crankset and I am wondering if the above would fit it. It is 172.5mm (which is the length I want) and is advertised as having a Shimano 130pcd fitting. Will this be okay? p.s. It's just the pedal arms/octalink fitting I'm looking at getting. I hope this makes sense as I'm new to all this and thanks in advance for your help.