Designers and users of any counter assembly employing the Veeder-Root counter should be aware of the speed limitation specified by the manufacturer.
The direct drive counter, which we use, has a recommended operating limit of 500 RPM. Since the counter records 10 counts per counter revolution, this implies a limit of 5000 counts per minute in order to stay within manufacturer’s specification.
The speed at which the limit is reached depends on the size of the bike wheel and the gearing employed to drive the counter. For a bike with a nominal riding constant of 10,000 counts/km (16090 counts per mile) this translates into a speed limit of 18.6 MPH, or 30 km/hr. My own bike has a wheel size of about 750 revolutions per mile, or 466 revolutions per kilometer. My counts per mile or km will depend on the gear ratio in the counter assembly.
Happily I don’t need to get into involved calculation. My normal calibration figure is about 20000 counts per mile using my chain-drive rig (which has thus far survived 300 km without observable wear or malfunction). This translates into a speed limit, for me, of 15 miles per hour. Unless I am on a steep downhill, it is rare for me to exceed this. I have done so, and so have many others, and no harm seems to have resulted.
Speed limits for other constants are seen below:
While these limits may seem a bit restrictive, it may be said that failures of the Veeder-Root counter are very rare. Thanks to David’s recent post. I now know of only one failure. There are probably more, but not enough to cause the populace to rise in revolt.
These limits should be taken into consideration by designers who intend to incorporate the Veeder-Root counter into their design.