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Discussion Starter · #1 ·
I think it goes without saying that everyone in here knows that Triumphs and BSA’s are parallel twins (both pistons move up and down at the same time—360° crank).
Has anyone created a crank to change this into a vertical twin, where the pistons are running opposite one another (180° crank), to get smoother balance? Just wondering.
 

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Discussion Starter · #3 ·
There are a number of parallel twins from the factories now with 76 deg cranks to get 90 deg twin (Ducati) balance. IIRC, there were flat trackers who tried that back in the '60's or so. This is more recent: M.A.P. Triumph 76 Offset Crank

Also, I rode a 360 crank Yam 650 and it seemed to vibrate badly.
Wow. I would love to hear a bike with that crank run!!!
 

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Discussion Starter · #4 · (Edited)
I think it goes without saying that everyone in here knows that Triumphs and BSA’s are parallel twins (both pistons move up and down at the same time—360° crank).
Has anyone created a crank to change this into a vertical twin, where the pistons are running opposite one another (180° crank), to get smoother balance? Just wondering.
I found this

]
 

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I believe 180° cranks come with their own vibration issues -- lower amplitude, higher frequency. (Meaning your hands tingle and numb out after a long ride, rather than throbbing painfully as they would on a 360° Triumph et al.) More knowledgeable guys are warmly invited to shoot big holes in this not-well-informed opinion.
 
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