Subject: RE: 205lb rider - 23 vs 25mm wide tires? Good question, this is one of those areas of tri-equipment that we just kind of take for granted and never reconsider the 23's that came on the bike.
Short answer: 25's CAN be faster. Longer answer: It depends. There are several variables to consider:
- Weight. 25's will weigh more than 23's
- Rolling resistance. 25's will roll with less deformation in the direction you are going, resulting in lower resistance. (The total deformation will be the same, just more of it will be lateral deformation).
- Aerodynamics: No clear answer here. Common sense says a more narrow profile would be more efficient, but aerodynamics are funny. Probably depends on your fork, frame, etc as to whether 23 or 25 is more aerodynamic.
- Comfor. 25's are more comfortable (smooth) than 23's, that's unanimous.
- Durability. (if that's the right word). 25's are slightly less susceptible to pinch flats than 23's.
- Availability. 25's are much less readily available than 23's, and in many fewer rubber compounds.
One thing (amongst many) that I do not know, and would be curious to find the answer to is: if you have a 25 rim, can you run a 23 tire on it? I know the tubes are good, but don't know about the tire. This would likely be the scenario if, say, you cut a tire on your warmup ride at a race...chances are pretty good you won't find a spare 25 laying around, and would be forced to go with a 23.
I confirmed my understanding of this here, but there are more resources available everywhere. Google will give you many more resources on this, it's been pretty thoroughly researched. |