Time Trail bike question?

Quoted post said:

Originally posted by LordViperScorpn
I know that time trial bikes differ in several ways from a road race bike. My question is on time trail bikes you often see a solid back wheel. I would guess that this helps cut down on wind resistance. IF it does cut down and make the bike faster how come you dont see the solid back wheel on bike used in normal races? Any explanation as to why time trial bike have different parts from your standard road racing bike would be help thanks.

The disc rear wheel has aerodynamic advantages over a normal spoked wheel. Air is directed smoothly around it rather than being churned turbulently behind a rim and in the spokes (which uses energy).
So discs are valuable in time trials and are also used extensively in track racing.
The problem with using a disc is a lack of stability if it hapens to be a windy day. The has a big sail area and any cross wind can make id very difficult to keep the bike pointed in the right direction.
I remember one windy TT I did in which a top level rider was present with his disc wheel. He had said to me after the finish that he had almost been blown off the road and into a cow field by the breeze. I personally didn't feel as much crosswind because i don't have a disc to catch the wind.
This lack of control can be tollerated in a TT because you are riding on your own but in a road race chances are if you get blown to the side you'll run into someone else.

Quoted post said:

Originally posted by tafi
The disc rear wheel has aerodynamic advantages over a normal spoked wheel. Air is directed smoothly around it rather than being churned turbulently behind a rim and in the spokes (which uses energy).
So discs are valuable in time trials and are also used extensively in track racing.
The problem with using a disc is a lack of stability if it hapens to be a windy day. The has a big sail area and any cross wind can make id very difficult to keep the bike pointed in the right direction.
I remember one windy TT I did in which a top level rider was present with his disc wheel. He had said to me after the finish that he had almost been blown off the road and into a cow field by the breeze. I personally didn't feel as much crosswind because i don't have a disc to catch the wind.
This lack of control can be tollerated in a TT because you are riding on your own but in a road race chances are if you get blown to the side you'll run into someone else.

Cornering and stopping with a disc sucks, the weight and momentum of the heavy wheel and usually poor breaking surface makes them dangerous for mass start events (watch a triathalon and see how many riders crash who don't have good bike handling skills, coupled with all of the aero goodies).
Besides the advantage using a disc in a mass start event would be marginal at best.

Wow! thinks for the information I think I understand little better now.