1970 A65 that followed me home

acadian

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Just picked up this treat, will have to cut my teeth on beezers, but she starts 1st kick and seems to run reasonable well, first order of business will be to locate a factory manual for the 70, I know the 70 is a bit different than the earlier A65's, but am not sure of differences with later models...

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acadian

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Strangely enough I find it to be remarkably comfortable to ride, much more so than my T120 or TR7. The P/O had the crank dynamically balanced when fitting hi-comp pistons so that's likely the reason. The other interesting thing I didn't expect was how freely the A65 revs, I'm regularly cruising around town in the 5K + rev range and she doesn't feel like she's going to grenade. Quite unexpected. Anyway, she's due for a top end rebuild at the very least, and I may even go for the devimead mod if I can find a North American outfit that still does it.
 

grandpaul

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The thing is with classic British big twins is, once you have complete assurance that everything whirling around inside is doing so in the specified manner, you mind your tach and learn to love it all the way up to the red zone. So what if it "sounds" strained, or "feels" busy, it's NORMAL. Enjoy it.
 
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my 68 A65 had a high frequency vibe that made my hands tingle after 20 miles or so....I went to a nearby gas station and bummed a double handful of lead tire balancing weights which I stuffed in handlebars vibes greatly reduced …...el cheapo style
 

RoadScholar

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I remember my 650 well. Hope you can survive the vibrations.
Getting the rotating and reciprocating parts properly balanced will widen the sweet spot quite a bit; assuming that you are willing to go through the effort to extract those parts. I had my 1970 B44 VS balanced and the service removed almost .100" from the drive side flywheel; it is now very smooth up to 50 MPH in high gear.

I also have a 1970 Lightning which will get the Alpha timing side upgrade and be balanced and clearanced. I haven't determined the balance factor yet, but will select one that gives me the best possibility of smoothness in the upper end of mid range RPM.
 
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The B44 has a wider driveside flywheel than the timing side, so to dynamically balance it, it makes sense to reduce its overall diameter.
 

RoadScholar

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The B44 has a wider driveside flywheel than the timing side, so to dynamically balance it, it makes sense to reduce its overall diameter.
Back in the day I had 2, 441s and 1, 500; both vibrated to beat-the-band, enough to tear the rear fenders; I didn't have the experience, tools, time or money to dig into their bottom ends, what money and time I did have I spent digging into the bottom ends of some of my more adventurous dates...

The '70 B44 VS is amazingly smooth; I expect a similar outcome when I finish the '70 Lightning. I recently finished a '70 TR6R which I had balanced and it, too, has become much smoother.
 
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Strangely enough I find it to be remarkably comfortable to ride, much more so than my T120 or TR7. The P/O had the crank dynamically balanced when fitting hi-comp pistons so that's likely the reason. The other interesting thing I didn't expect was how freely the A65 revs, I'm regularly cruising around town in the 5K + rev range and she doesn't feel like she's going to grenade. Quite unexpected. Anyway, she's due for a top end rebuild at the very least, and I may even go for the devimead mod if I can find a North American outfit that still does it.
I had my crank converted by Frank Deihl’s Classic Cycle in South Carolina.
 
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A correctly set up stock bottom end along with an aftermarket oil filter should last a long time for a street bike.
 
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Beautiful Beezer looks exactly like my 1970 Thunderbolt but mine has the optional rust & locked up motor option. Picked her up in the neighboring town in the early 80's for $80 that's back when you could find them still sitting around for a reasonable price poor ole girl had been sitting out side in the elements for along time.

Mark
 
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