Citation needed
Smaller wheel decrease trail, mean quicker handling.
Adding 38mm tyres on 650b will make any road bike design for 700c x 28mm handle quicker, however it may not be obvious.
But you said slower, not handles slower. Skinnier 700c will roll faster
@edscoble started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Citation needed