Update to this thread..
Its been a while and I made some changes to my bikes, so here is the first one.

The Raleigh is now a 451 bike from the 406 before.

Raleigh MV9 sp by jenkwang, on Flickr

Its really interesting how much difference the 451 wheels make to a ride.
The bike feels even more "road bike like", maybe because it feels higher (higher center of gravity).
451 also seems to hold speeds better and roll over short climbs (eg 100m )easier most likely due to the holding of the momentum.
I have found this latter aspect to be rather stark between 700c wheels and 406 ones.
On 700c, on such short climbs, there is little effort needed as the bike basically rolls for at least half the climb, while on the 406, I'd have started to pedal 1/3 into the climb.
So in this respect, 451 certainly is a bit better than 406.


I'm not a measurement kind of guy, so I just take the bike out, run it over the past few months over the usual routes and group rides to see how the bike rides and my overall position in the usual peleton.

I have to say that the bike configured with 451 wheels (Tyrell AM9) is really close to a 700c bike.
In many group rides, its been able to not just keep up, but pull the group and often enough get within the top 3-4 finishers in the ride.
Base on what I later observe on my Strava, I'd still think that there is a 1kph to 1.5kph delta to my tri bike, but to be able to ride in a group of 700c bikes w/o feeling severely handicapped is great (esp on poor weather days when I'd not need to clean up the Raleigh after getting back from the ride at 11pm)