List, I just read a post from Patrick Moore with thread title "to make 26" rim'd atlantis fast randonneur: suggestions?", the quote is, "Jan's idea that smaller wheels ought to have fatter tires for the best handling compared to larger wheels has not been true in my experience." I have read similar statements from others and wanted to comment.
I did actually purchase the Bicycle Quarterly (BQ) article, although I don't have it on hand as I write. As I recall, the handling of 3 bikes with similar geometry but different wheelsize was compared. The BQ conclusion was that the bikes handled differently depending on tire width, and the purported explanation was that the moment of inertia of the wheel was the cause of a difference in handling. Since wider tires are generally heavier, and smaller diameter wheels light, one may infer the recommendation that smaller diameter wheels should have wider tires than larger diameter wheels. Here's what I want to challenge: the geometry of the 3 bikes was similar, I believe they all used a 73 degree head angle. So yes, if you want to keep the head angle constant as wheel size changes (and it is a head angle commonly used for road bikes with 700C wheels), then probably a mountain bike diameter 26" wheel and a skinny tire is not the best combination. However, bike designers (at least the better ones) know to change (decrease) the head angle and other aspects of the frame geometry for a smaller diameter / similar tire width wheel precisely because the steering of the smaller diameter and lower moment of inertia wheel is quicker and the stability is less. So, I don't think the BQ article proved a 26" wheel bike has poor handling with narrow tires, it just showed that if the geometry is taken say from a design that works well for narrow 700C wheels and no compensating changes are made, the handling will be sub-optimal. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
