superrocket question-

[63a10r]

i gotta ask. what kind of highway speed and stamina can i realistically expect from a 1963 superrocket.

[fido]

With any of these British vertical twins, SR, Bonnie, Norton 650SS etc you tend to get vibration at high revs. The bikes seem to keep going pretty well despite this as long as all the nuts & bolts are tight. It can get uncomfortable for the rider though to sustain high cruising speeds. i would therefore suggest that you expect to cruise at 70mph or less with bursts of higher speed for overtaking. With such use I would expect the bike to have more stamina than the rider.

[LJ.]

Talking of vibration... excuse me going off topic... I find that the original bike parts seem to be okay and stay on firmly. It is the extras that I have put on that seem to suffer. Example... My handle bar fairing, nuts & bolts okay but 'P' bracket broken in half. Two 'U' bolts holding leg shields on... fell off! Mind you this is after a 1,715 mile ride! So she aint done too bad.  :)

[63a10r]

barefoot ed here. i had a 69 bonny for 13 years, and i could easily run 90 all day long. it WAS a matter of whether i could keep up with it, vibrations and all. im just wondering if the a10 can sustain hiway speeds of 75 or so?

[LJ.]

Ed... I think that unless you know what the condition of your motor is then i'd best stick to under 70mph.

The most I have done on mine is 67mph, I usually stick between 55-60. The reason is that the conrods are in a very 'knocked' about condition and having heard that small knocks an dings are fracturing points, then I would not want to push the old girl too hard.

Eventually the day will come after many miles when I will have to have a complete overhall of the engine. I will probably go for an end feed roller bearing conversion and have new conrods, possibly also have the crankshaft dynamically balanced as well. *Then* I should feel more confident about going well over 70mph. (an bugger it all up!) 

[63a10r]

im puttin this engine together as a COMPLETE rebuild to super rocket specs, except that i will be using lower c.r. than the 10.5 to 1 the book specifies. this is due to my triumph experience using HIGH comp pistons. the bike was a missle but it beat me to death if i was goin much further than 20 or 30 miles.

[trevinoz]

Very wise to reduce compression ratio. I run about 8:1 and find it ok. I would look hard at BSA's timing recommendation of 13/32" btdc as I have found the engine pings badly under load. Eddie Dow suggested 5/16" btdc. Back in the 60's I tried running 10.5:1 and found I had to use 100 plus octane fuel. Also I broke the barrel off above the flange. Very expensive exercise. Have a look at the combustion chambers on your head, most of them look like a shotgun has blasted them due to the pinging/detonation.

[trevinoz]

Just another thought, get your engine dynamically balanced, it's well worth it.

[63a10r]

apperantly, the previous owner felt the same way. the chambers are mirrored bowls now, no pits at all. the +.040 pistons that were inside were flat tops.

[BrianDallasTX]

Aw Ed you should take the credit for the work.  I cruise around 70 no problem.  Most of the mileage I put on is in the city, but sustained cruising is no problem.  It becomes a battle of the vibrations.  I notice it getting "buzzy" around 65-70.  75 your teeth start rattling.  I also noticed that at 70mph I am around 3500 rpm in 4th, and maybe changing the sproket by a tooth or two would lower the rpm at speed and therefore the vibes, however the low end would suffer- just the trade off.

[Bernie in Silver Spring]

Greetings speed devils.  I am new to this forum and enjoying it .  I run an A-7 Flash, 1961.  Man, you guys sound like your travelin at the speed of sound on those A-10s... I rarely push 60mph on my Flash . 
Looking for a bike lift handle #42-6865...tired of impaling my hand on the air pump mounting ear!
Cheers