Belt drive conversion on a 1974 T150

[stevestriumph]

Greetings fellow enthusiasts. I am building a 1974 Triumph T150 and I would like your opinion on whether or not to use a tensioner when converting to a belt drive in the primary. I got mixed messages from the supplier of the belt, so it left me unsure as to use a tensioner or not. At first the supplier said "you can use a tensioner if necessary", followed later by "there is no need for a tensioner". My concern is if the belt does eventually stretch, then a tensioner would be advisable, but if there is no stretch issues a tensioner is not necessary.  I am interested in your opinions and input. Also, the supplier claims that with using this belt drive, you can run the primary dry. Aren't there other parts within the primary that need lubrication? See attached picture of belt drive. Thanks in advance for any information. Steve
 

[Rex]

The beauty of these toothed belts is that they don't stretch. You wouldn't want variable cam timing in your car, would you? 

[L.A.B.]

They don't generally need a tensioner (as long as the belt is correctly tensioned in the first place) and it is possible to run the triple belt 'dry' (belt driven oil pump etc.) but the knowledge and experience regarding belt drives for triples, wet or dry, is more likely to be found on the Triplesonline forum. I recommend you join, search and read previous "wet/dry belt drive" threads and ask questions there if necessary.

http://www.triplesonline.com/