Quote Originally Posted by Bluetree View Post
I recommend going to a fitter before building up a new frame. If they have a FitCycle, or equivalent, it can tell you exactly the size components you need. They can dial in your new frame's exact geometry, and measure your needs according to a fit, or by taking measurements off your existing bike.

When I built up my last frame, I assumed I needed the same size stem as my last one, but because of the different geometry and setback, it turned out I needed a longer one... a mistake that could have cost $100+ since I was buying a lot of stuff on eBay.

Your intentions also have to be considered when choosing components. Do you prefer aero, or lightweight? Race, climb, touring or all-purpose? If you climb alot, you'll want to consider spending a bit more for lighter, more expensive carbon parts. If you want to race, perhaps your greatest emphasis should be on a wheelset. Do you want clinchers, tubulars, or tubeless... Each has aspects of ease vs performance.

Also keep in mind the Golden Rule of bikes:
Lightweight. Strong. Inexpensive.... Pick two.

Enjoy yourself in this process... Bike building is fun!
I totally second all of this!
I guess I was assuming the builder was also an experienced fitter who would first measure you thoroughly, look at your current bike's geometry, figure out what needs to be different and what should stay the same (based on both their knowledge and on your input about your current riding issues), take your riding style and goals into account...then work up the right geometry, the right materials and components to get you where you want to be....not just weld up a frame based on a few measurements and then have someone else fit you to it later.
Ideally, the whole idea of a custom bike is that the bike should be fitted to YOU (even before the frame is created), not you being fitted to the bike. A custom 'whole bike plan' should all be a seamless integration of geometry, components, and fit. Having a mutual vision in mind for the new bike, shared between you and the builder, is crucial. Margo at Luna Cycles really did it all for me when making my new bike, and now I am spoiled.
If you plan on slowly collecting components yourself, you'll have to coordinate with the builder in terms of putting rack braze-ons, deciding on rim and tire widths, brake/fork clearance for fenders if you want them....things like that cannot be easily changed after the frame is built. Again, having a vision for your new bike and planning ahead with the frame builder will be important to get the outcome you want.
It's very exciting! I know exactly how thrilled you must feel...congratulations on planning for your new baby!