What size tubes are needed for 650B tires? Has Rivendell made 650B popular enough again that tubes are made specifically for this size? If not, 650A/ 26x1 3/8 at 590mm would be closer to the 650B 584mm than would 650C at 571mm. In fact 650A and 650B are a bit closer than 27" and 700C, which use the same tubes. However, I believe 650A, at least in recent decades, was used mostly 3 Speed bikes, so available tubes may be pretty wide, whereas the newer 650B tires can be as narrow as 32 mm. What is the experience of you 650B users out there?
Regards,
Jerry Moos
Big Spring, TX