Hi,
I've seen quite a few times people mention that if you build up a bike component-wise its a labor of love and will be more expensive than what the manufacturers sell. But I just want to point out it is possible IF you buy your components from the UK.
The details are below, but essentially for $850 I got a steel bike with complete 5800 drive train and other entry level components. If your wondering why I bought other entry level components, I'm going to ride the bike with these components and then upgrade in 6 months.
For $895 I could have bought a Gran Premio Elite (a steel bike) from BD which contains most of the 5800 drive train but compromises on the cranks, brakes and BB. Also, according to reviews the BD bike weights 21.8 pounds and mine should come in at under 20 pounds.
Now of course the big difference is my bike is lying around in parts and I have to put it together, but so far so good. Putting together the steering assembly took 40 minutes including cutting down the steering tube. I estimate it will take me about 10 hours to assemble.
Details
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The gran premio elite specs are here
Save Up To 60% Off Pro Level Steel Road Bikes Commuting Commuter Bikes Motobecane Gran Premio PRO
My cost break down is:
Frameset: Breezer Venturi $300 (BikeWagon)
Entire 5800 Groupset: $350 (Wiggle or Merlins)
Wheels: Camparelo Khashims Assymetric 2016 $118 (Merlin)
Tires, bottle cages, pedals, seat, handlebars, tape etc $80 (Ribble)
I think my bike is better speced than the BD offering. The Gran Premio frame appears to have a regular Chromly rear triangle (not 520) and BD uses a non-Shimano brakes, cranks and BB. The Campy Khashims and the RS11 wheelset the BD bike has are comparable.