Wordman's Build (with questions, answers, and suggestions)

Correct, the stock Triumph crank is a 360°. The Triumph doesn't have the central bearing though, so it also has a crank "whip" factor (the crank flexes in the middle like a jumprope. Going with a 76° crank, while a lot more expensive for a Triumph, does even more to quell the vibration.

 

Triumph always had a pretty high rev limit, they just felt like they might come apart (and sometimes did) when you approached it. In racing, the offset "billet" crank would allow you to stay at the limit longer and with fewer chances of turning the thing into a grenade, I would think. As I am going with a stroker crank and a much larger bore (840cc), I plan on staying with 9:1 (at most) compression and fairly "soft" cams so I won't have to rev the snot out of it to hit the highway now and again. The whole exercise is to build a strong and reliable Triumph.

 

I've been running an external filter for years. The sludge trap was a good idea in the 30s and 40s, but with the advent of detergent oils, a good filter is a far better solution.

 

I'll be running a belt drive primary on the Triumph. I like the MAP belt drive, but the Bob Newby is my favorite.

The only issue is, the Newby doesn't have a cush-drive (the cush is in the clutch assembly on a Triumph).

Well, XS650 tech to the rescue! Just received a nice TX500 rear hub and brake plate. The TX wheel is drilled exactly the same as the XS, so I can use the XS flanged aluminum wheel.




And since I already run an XS650 front wheel... Yes!

 

Actually, the XS is usually done a 277° (83°) offset because of the splines.

76° is what Phil Irving suggested for parallel twins (though this is based on rod length as well, and so is not definite).