Originally Posted by Campag4life

Let's clear the air a bit. No flame war unless you want to disparage the truth. Unless you need a custom geometry...you implied you are a big guy with long legs and short torso...I am the same...big guy with long legs and short torso....I don't need a custom geometry with the thousands of different geometries out there...and neither do you or the plethora of others who seek a custom geometry because they think they need to. Shack needs a custom geometry but you and me don't. Further, and this plays into riders understanding the difference between a good frame versus bad, most don't even know what their best geometry is and custom frame builders who try to assist in this effort I would say mostly get it wrong. Lots of custom bikes on the road with riders in a goofy position and riser stem with big stack of spacers.

And let's say your builder knows what he is doing...or at least fabricate a bike that won't fail. But take a moment and contrast your builder to Specialized and Trek who have had carbon failures in the field. Between Specialized and Trek, they are encyclopedic about frame fabrication and stress/strain and manufacturing variation. And yet in mass production they have had failures which they tried to eliminate by recalls of certain bike models. This is after rigorous testing, each frame being prototyped...sometimes with multiple designs for each frame size and specific geometry and the highest scrutiny of quality control. The highest level of process control and yet failures seep into the field and people get hurt. So no, I don't think much of boutique builders. Compared to large staffs of engineers that comprise all the big bike brands, boutique guys are clueless. Your bike...I am sorry but it will be the stone age of carbon with straight sections. Hopefully your builder will assemble it and it won't fail. The pedigree of your frame tubes is meaningless. It doesn't matter if each tube was made of gold. What matters is the modulus of flex in differential planes and uniform tubes don't have one. Further there isn't a PhD in engineering that is smart enough to predict how a hodgepodge of the best 'uniform' tubing on the planet will perform together. You may recall the long thread a while back about the guy who had a custom Ti bike made from one of the top guys...a very anal guy who obviously didn't understand the 'art' or 'variation' of individual frame building...and he was hugely disappointed in the frame. It rode much stiffer than he wanted. This was after a long discussion including in writing what he wanted. Why did this occur? Because when a custom geometry is constructed, it is unique to a given rider and virtually impossible to nail ride and handling characteristics...even with a top builder like in the case of the Ti builder. This is why Specialized and Trek even with all their computer aided design and FEA and staff of engineers still have prototype frames to a specific geometry...one or multiple for each frame size, and then ride, test and change. Its iterative. There is no way a boutique guy could stay in business with this rigor but the only way the best ride and handling performance bike can created.

Above goes right over the head of anybody who wants or feel they need a custom frame. A custom frame isn't a custom watch or even a flower arrangement.

Even top companies get it wrong btw...all the time. It could be argued that when Spesh made the SL3 Tarmac a few years back after winning the TdF on the SL2...pro feedback was to stiffen the bike which they did in spades. They made it too stiff. This is after making prototypes specific to a 'known' geometry and testing and re-testing. They responded to this feedback which resulted in the award winning SL4 bike which also has won the TdF and the now SL5 bike which revises frame bending for small and big frame sizes to make the riding experience more equivalent for a larger cross section of riders....small riders and big rider bike performance was more of a compromise in previous years. This is based upon the best designers in the world benefitting from a lot of computer analysis, strain gauging and road load testing and timing bikes through handling courses. This cannot be sustained with boutique builders...not even on the same planet. A boutique guy can't build 5 to 10 bikes to produce a given model like a top brand can. Spesh I will add got it wrong again. The SL2 Roubaix is perhaps the most popular carbon bike ever sold. It was a friendly riding bike that everybody but top racers loved. No it didn't have the punch of a stiffer Tarmac however. Enter the SL3 Roubaix which is the best bike I have ridden. A stiff but not unrelentingly so stiff bike that is both fast but minimizes fatigue on long rides. Well, Spesh in their wisdom took what I would consider almost a perfect bike if there is such a thing and made it as stiff as a Tarmac. Endurance geometry but race stiffness. An outcry ensued. Magazine testers and owners don't know what to make of the bike...and still don't....which has a relatively rough ride compared to previous versions. So basically Spesh with all their R&D screwed the pooch with the Roubaix SL4. The Roubaix to buy if you can't find a used SL3 will be the SL5. Mark my words. They will improve vertical compliancy and restore the friendly nature of the bike for the demographic it was intended for just like they tuned the ride of the Tarmac SL3 to create perhaps the most popular and winning race bike of all time.

So if the best and the brightest get it wrong including Microsoft which they do and in fact frequently, then the guy who started to build stuff in their garage with no comparable data base doesn't have a chance. Oh they may hit the lottery once in a while but a good chance they won't.

Good luck.