I have a bell 4 function dig speedometer and am trying to figure out what i should enter for the wheel factor.
My front tire says 26 x 1.95
In the manual that came with speedo theres a chart and the closest i can get to a 26" wheel diameter with a 1.95 width is the following
26" (650A) (= wheel factor of 2073) ..or...
ATB 26" X 1.75 (=2045) .. or...
ATB 26 X 2 (650B) (=2099)
( I have no idea what "ATB" or the "A" or "B" stands for, i was hoping someone who knows bikes could discipher?)
In the manual it says that if your wheel size is not listed in the chart, you just need to convert wheel size to mm, then multiply by pie.
But how does wheel width factor into this?
Also, what math are they doing to arrive at those wheel factors?
I can understand the first one (26 x 2.54 x 10 x pie = 2074.71), but have no idea how tire width factors into the wheel factor?
Also, the wheel diameter 26.6" (700 X 25C) is highlighted in bold in the manual for computer, as if that is a common wheel size or something..
Thanksfor any clarification, i'm totally confused.