Cable drive speedo ratios - 60mph = 1400rpm? 2:1?

[andyxlh]

Hello all
I'm pretty sure the cable drive speedo on my '89 and '91 XLH is 2:1
How does that go with the common 60mph/1400 rpm ration that seems to be very common with aftermarket speedos?
I'm looking at this for my Cafe racer build, but am not sure if it will work - the speedo cable thread is the right size I think
Anybody know if this would work?
Best wishes
Andy
Sydney

[smoserx1]

I really don't have a clue but I would think that in addition to the speedometer itself the drive unit for the front wheel would have to come into play.  The RPM of the wheel at 60 mph would be different for a 16 inch wheel than for instance a 21 inch wheel, wouldn't it?

[koko3052]

Not necessarily because of the sidewall height. Most tires will have catalogue info on RPM, revolutions per mile, or can just measure the circumference on the mounted tires.

[Hybredhog]

   A 19" tire is only slightly taller than the average 16", and a 21" would turn even over slower. The Softail 2240:60 ratio could make up for that, but your limited on what drives are available, unless you got into machining adaptors to foreign drive units. The bottom line would be to just go out and see what your bike is actually doing at 60mph, and make a note to self.

[JW113]

Is this helpful?

[attach=0]

-JW

[andyxlh]

Yes it is, thank you!