I just completed aproximately 20 hours studying what to do to make my Brompton a better ride, and I believe some of my findings might be relevant for other folder enthusiasts that don't browse around road bike forums and other places where performance is way more important than here.
As some of you know, I live in the USA but due to career (and lifestyle) I do travel a lot. Spending time (ANY TIME) assemblying a bike to make it ride-ready is not a good fit for my needs and personal preference, so the Brompton is the only option for me, even though I would prefer something faster, with bigger wheel, etc...the Brompton is what I have to work with for now.
Since Last March (when I purchased this red Brompton that I currently have) I have been complaining about speed. I can maintain a 14mph pace without struggling, but to keep up with 18mph for more than 60 minutes becomes demanding. Since then, my desire to make the bike faster focused predominantly on weight, and that was a mistake. Wind, poor riding geometry and friction (bearing, chain, BB, hubs) are my real enemies.
After some basic applied math (well, maybe not so basic if you take a look at my notebook), If I had the super power of unlimited budget and could invest all the money in the world to make my Brompton the lightest Brompton in the world, I still would perform "poorly" due to aerodynamics, poor riding geometry and friction.
Weight is still something important (specially if you plan on carrying the bike a lot like I do), but the price of upgrades (incluing rear triangle, front fork and bids of Titanium) and the overall performance results are just silly. If I were losing medals after severe climbs by seconds, that would make good sense. But not under the current circumstances.
With that in mind, my Brompton is now featuring some of the heaviest stuff that I had around, and my focus on improving performance will be on the following (in order of importance):
-Reduce wind resistance by changing cockpit and riding geometry;
-increase comfort. you ride more often if you enjoy riding.
-increase fitness conditioning specific for biking (interval training and spinning);
-Reduce friction (including rotational mass and hub quality);
-reduce total rolling mass by losing weight. Instead of struggling to lose 4 pounds on my bike, I am going to lose 15 pounds on myself.
Let the fun begin. Freds, weight nazis and zen comments all very welcome.
PS: Don't forget to read one of the first and most relevant articles of my studies: