Swapping Frames


New Member
Jul 9, 2015
I'm thinking of switching to a steel frame road bike and I am toying with the idea of simply buying a frame and moving all the components and wheel-set over from my current road bike as an alternative to buying a new complete bike. Through work I can get a deal on Soma frames and I like the looks of the Soma Smoothie ES. My current road bike is a Giant Defy 1 (circa 2009). My question is if I did purchase the Soma Smoothie ES how much of my Giant Defy could simply be swapped over to the new frame and what would I need to purchase new? I have a fair amount of bicycle wrenching experience but I have never done anything like this. Again, I am looking at this frame swap as a way to save money so if I am going to need to purchase a bunch of new parts I will instead look at buying a complete or just resist the urge to ride something new haha.
Stuff that may need replacing - w/o having checked the specs:
Seat post and front derailer, due to seat tube diameter.
Bottom bracket, due to BB shell width and threading. Or possibly press-fit.
Crankset, see above.
Headset, due to head tube diameter.
Fork, due to head tube length.
Possibly the front derailleur or band due to mounting style or seat tube diameter change.
You know my brother and I use to have a lot of bikes growing up. Eventually, we would have a bunch of old bikes stored away at the house. As a side project we would trade out frames and parts just for the hell of it and we came up with some weird and some times interesting looking bikes. We would call it the Frankenstien bikes.
I was able to swap a front clamp style derailleur from an aluminum road bike with a larger diameter seat tube to a steel frame by making a shim out of strips of a plastic pop bottle. I cut the strips just slightly larger than the clamp, I had to use several strips, but it is near invisible and has held up fine after a few seasons of riding.

There are shims you can by mail order as well.