In October this year I bought a "Les Harris" Triumph T140. The previous owner was my friend from France who passed away a couple of years ago and his son offered it to me to purchase. The bike hasn't been run since about 1999 and there was a lot of rust in the tank and evidence of many oil leaks, so I have completely stripped it to make sure all is well. It is now more or less ready for re-assembly, but there is one problem that I can't make my mind up on. The Les Harris Bonneville's had the TSS crank fitted which in it's original state was a much more rigid design than the original having bigger big end journals and is fully machined and also heavier and I understand reduced vibration, but when fitted to the L.H. Bonneville's, was modified by having the big end journals reduced to the same diameter as the standard 650/750 but was otherwise left as the TSS, i.e. heavier. I don't know if this bike vibration-wise is smooth or vibrates a lot? I never asked my friend, who obviously is unable to tell me now and I haven't run it at all since purchasing it as there were several issues with it and after purchasingI immediately stripped it down. So my quandary is whether to get the crankshaft balanced or not, and if so, to what percentage as it is heavier than a standard T140 crank. I contacted Basset Down who are a well know balancing company in the UK and they confirmed that they have never balanced one of these cranks from the L/H Bonneville so has no feedback as to what works etc. Another person I know had theirs balanced to 81% and wasn't happy with it. So should I; 1. Reassemble as is and see what it's like hoping for the best and if it's bad strip it down and send off for balancing with the known data? 2. Get it balanced leaving the balance factor as it is, but remove any "rocking couple?" 3. Any other suggestions. I am tempted to re-build leaving it as it is, but to strip it down again is quite a bit of work. Offending item is below.