Steven, it would appear that you aren't too familiar with the layout of the Triumph twin engine, or the lingo used to describe it? If so I would suggest you read the workshop manuals
, which you can find here: www.classicbike.biz
Anyway, I have attached a drawing which shows the timing case. The two cam wheels and the intermediate, or "idler" wheel is shown, plus the crankshaft pinion. The intermediate or idler has a pin or shaft on which it spins. It's the "hole" for that shaft I'm talking about. With the electric foot set-up it's the shaft that spins, which is why the factory installed a bronze bearing in the exact same location as the shaft.
Hope this helps.