What steps to take to replace bike frame I've always known my bike frame was too big for me. I got a great deal on the whole bike when I bought it seven years ago. It was an S-Works, probably from the '90s, with all Ultegra gear in great shape.

I find myself on my bike more every week, and the size is beginning to cause me aches, as I'm too stretched out on the bars and have a serious hunch. Getting a new bike or replacing this frame have been on my mind now for months.

All of my components are in okay shape. I'm semi-confident that with some time (and some help) I could move them to a new frame. My concern was that this new frame might not be compatible with my components. Some things, like the shifters, I'm not concerned about. But I am concerned about things like the wheel and bottom bracket.

So my question is, what are the main compatibility issues I could run into with putting old gear on a new bike frame and how can I avoid them?
There are many issues for the new frame:


Fork drop out (front wheel spacing) might be wider, 100 mm for most modern bike
Frame dropout (rear wheel spacing) might wider, 135 for most modern bike
Headset likely to be wider, so you have to buy new headset with compatibility to a 1" fork (I guess?), 1-1/8 inch to 1-1/2 inch for modern bike
Bottom bracket is likely to be ok
Front derailleur clamp may be too small
Seat diameter might be different 


Rules of thumb is that if the bike has no sentimental values, it is always more economical to use that money and buy a second-hand bike. Unless you would like to spend extra money to tinker and have fun with the bike in your own time.