The normal way in which a liquid can be controlled in terms of its temperature in these types of systems is by using a thermostat to control the amount of flow going to the cooler.

The most well known example of this is a thermostat in the water cooling system of a car.

Several years ago I looked at the availability of oil thermostats to fit into the triple engine oil system. I looked only at units that were commercially available.

Many years ago Norman Hyde at my suggestion sold a thermostat for this purpose based on a unit made by MOCAL in UK and intended for use on sports and racing cars. However this unit has not been available for some years.

After looking at commercially available units several years ago I recommended the Trucool 708-4739 P6 thermostat. This is made in North America and subsequent to the recommendation has been fitted to about 15 triples to my knowledge and certainly more by riders who have sourced the thermostat independently.

One of these Trucool (TC) thermostats was fitted by Frank in Germany. He reported on the TOL website a problem due to the failure of the thermostat.

I offered to examine the failed unit and Frank sent the unit to me in US.

Concurrently Dave Madigan (of MAD Components) had developed his own design of thermostat (DM) and asked me to examine one of his units and give a view on it.

So, this note is aimed at comparing the TC and DM units and also trying to identify the fault on Franks TC unit.