Abbott Hubodometer - http://www.atrol.com/hubodom.htm - "Put them on
trucks, tractors, trailers, buses, dollies, farm equipment, and even golf
carts." Hubodometer (specify tire size) - $40.00
At Veeder, www.vr-hubodometer.com/hubo/HuboAppGuide.pdf, there is a table
of Revolutions Per Mile of many tire sizes. If you want to be really
accurate, you can tow the trailer slowly along an accurately marked
roadway while an assistant counts the revolutions of the tire.
The listed RPM for an 8.25R15 Bridgestone is 637, which is a compromise
between the new tire RPM (628) and the worn-to-limit tire RPM.
Goodyear 8.25R15TR: 624.
For a Firestone 7.50-15TR the RPM is 676.
Tire companies can supply you with the RPM of their tires.
Stemco, www.stemco.com/571-2905%20Hubo.pdf: "
Rugged construction.Naval brass on steel. Noplastic drive
components.Rugged construction.Naval brass on steel. Noplastic drive
components.Rugged construction.Naval brass on steel. No plastic drive
components."
www.rvedition.com/ offers a "Hubo" for $99.95 + shipping to RVers (2 1/2
x the price for us RVers of course).
As our hubs' caps are pressfitted in, it would not be good to fasten the
hubodometer to the cap - the cap and odometer might fall off. A bracket
spanning the hub might be necessary. If you have hubs that have threaded
caps, like my 1952 Spartanette (Warner brakes), it should be OK to mount
the odometer directly to the cap. Heavy trucks mount the odo to the hub
cap screws, as they are arranged like the axle screws on 3/4T & 1T light
truck axles.
Al