Question: I’m short and shopping for a new bike. I’ve found that many with small frames use 650C wheels. Are there any disadvantages to having these smaller wheels? I notice that triathletes often prefer 650C no matter how tall they are. — Caren C.
Coach Fred Matheny Replies: Smaller wheels are thought to create less wind resistance. Many triathletes choose bikes built for 650C rather than typical 700C wheels because their riding is primarily time trialing where aerodynamics are important. The smaller diameter means a bit more strength, too, because the spokes are shorter and the rim is more rigid.
The disadvantages are minor and include a somewhat smaller selection of tires and tubes than for 700C wheels. The tread wears a bit faster because smaller tires go around more times to cover a given distance.
One other drawback could occur on a tour into rural areas. If you have a problem that requires replacement spokes or a rim (or even a tire), a small-town bike shop may not have the parts in stock.
You can help yourself by packing several spare spokes and a folding 650C tire, along with an extra spare tube.