Originally Posted by
Kontact
Tire size and wheel size are mainly relevant because we're mainly talking about racing bikes, and racing bikes are supposed to be more alike than different. Which allows them to receive neutral support wheels and that sort of thing. No one frets about tire size with MTBs or recumbents because there isn't that history and group rides don't happen the same way. There is no reason not to use 650c wheels if you want to, but it is understandable that people don't feel like they quite fit their conception of road bike. They also seem to work fine down to 5'2" if the bike is designed well.
Who's talking specifically about road racing bikes here? No one has previously mentioned 'neutral support' which is a laughable concept for most of us. I have never gone out on a bike ride with the idea that someone other than myself would be responsible for repairing my bike or making arrangements to get me back home. So far, so good (and I've never been stranded by a tube/tire failure).
I'm more likely to go on a group MTB ride than a group road ride FWIW, and based on what I see on Strava I'm not alone there.
All I see against smaller-than-700c wheels so far in this thread is tradition and a basic reluctance to accept that one size doesn't fit all.