I've been lurking on these boards for about half a year and finally have a question to ask. I have a Shogun from the 80s and want to make it a bike for friends to ride with me. I live in VA around the Blue Ridge mountains so it is quite hilly in the area. Being that the currently installed crank is a 52/42 SAKAE SA it will be hard for my friends to keep up with me on my bike. So my question is what modern chainrings will fit on my current crank. I noticed that the Tiagra chainrings have the same measurements (I think) but do not want to buy if it will not work. I was looking for around a 34 chainring to replace the 42. Thank you for your help.