As I was taking a picture of the speedometer on my '68 305 Dream before dismantling it for painting, and looking thru the viewfinder of my camera at the speedometer face and for the first time in 15 years noticed the equation; 60mph=2250 r.p.m. At first it didn't register how low rpm this was for a relatively small displacement but after remembering my CB350 turning close to 6,000 rpm at 60mph; the same for the 350f four cylinder; the 750 Honda was running about 4,500 at 60mph. Is this the right speedometer for a 68 dream, and if so how does the Dream motor produce the torque at such low rpm?
Clarence
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1968 305 Dream
1979 XR185
Fuji speedometer writing
Fuji speedometer writing
i believe that equation means 2250 RPM's of the speedometer cable equals 60 MPH. the speedometer is driven by the front wheel....not the engine. with the gearbox having 4 speeds you couldn't have a speedometer driven by the engine.
FYI, all American auto mechanical speedometers are calibrated to 1000 RPM's on the speedometer cable equals 60 MPH indicated. that makes it easy to adapt speedometers from different cars and for them to read accurately. all you need to do is change the drive and driven gears in the tailshaft of the transmission that drives the speedometer cable to allow for different rear end gear ratios and tire diameter
fuji speedometer writing305:
That sounds like the right solution to the equation, as my math teacher would say. When I was thinking it was the engine rpm, I couldn't figure out how they knew what sprockets I was using, duh! thanks Clarence ---------- '68 Honda Dream 79 XR 185
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