Originally Posted by
kidshibuya
You should look at other bikes that can also fold as small, maybe bike Friday or something, others should be able to come up with some. You need much lighter weight, drop bars and good gearing, Bromtpon cant provide any of those.
Really?
Source:
https://www.cyclechat.net/threads/le...n-ever.238033/
If the OP's requirement "bike must fit in an overhead compartment" stands true there is not much choice apart from a Brompton (if any at all). So if this is the core requirement one has to start from there and see what's possible. It is obvious that a Brompton is not the perfect (or even a competitive) Triathlon bike but the OP seems to be aware of that. And I know personally people who have used a Brompton for Triathlon (no official ones but an inofficial fun event with much smaller distances than normal) and came out well.
This on the other hand
I wanted to start with the first of the upgrades being a kinetic 11 speed internal hub...
makes me wonder if the OP is aware of the technical limitations of a stock brompton. Clearly it can be done but needs a lot of fiddeling and expensive aftermarket parts (like i.e. a Vostok rear triangle) and will at the same time influence weight and folded size as well to a degree - IMHO w/o delivering additional value accordingly. So maybe the OP should either rethink the overhead-compartment part (which at least in Europe would possibly not work reliably anyway) and this way open up the choice of possible bikes or start with a S2Ex model and stick relatively close to the factory configuration/shape, adding maybe things like a third cog, a bigger chainwheel, a lighter seat-post, replacing steel with ti-parts, and add (removable) triathlon bar add-ons. Stuff like that. Will probably work but needs time and effort.
Originally Posted by
kidshibuya
Maybe it would, maybe it wouldn't - but it would not fit into an overhead compartment I'd assume and thus not in the OP's requirements as well.