Originally Posted by
Calsun
The "endurance" bikes have frame geometry that is easier to manage at speed on downhill sections and less demanding for the rider. They are quite similar to the first triathlon bicycles in their frame geometry and have more fork rake and lower head tube angles.
In terms of a softer ride you get that with the use of wider tires. My Specialized bike came from the factory with 28mm tires but the rims (and hydraulic brakes) can allow the use of tires up to 64mm in width. The wider tires have greater volume and so can support weight at lower tire pressures. Lower tire pressures makes for a "softer" ride. There is a huge difference in the ride of the bike with the 28mm tires at 90F/95R pressure and my bike with 23mm tires where the pressures needed are 100F/110R. With wider tires I could of course use an even lower tire pressure as with my mountain bikes with their 29x1.95 tires that I run at 29F/32R tire pressures.
Good info and something I looked at when I rode my Rivendell but I don't really concern myself as much with softer rides, by comfortable I mean in terms of geometry. I like the agility of narrower tires and probably would stay around 28 or 25. I had some wide Schwalbe tires on a bike a while back and I hated it, they're still sitting in my garage.