Top speed....

[Russell]

Hi! I'm new here.

I had a Superhawk back in 1966, when I was younger and even more foolish and a flying jets as a student pilot in the Canadian Armed Forces. This was in Moose Jaw Saskatchewan, where the roads are long, flat and straight and the winds tend to be strong and steady.

One time I was riding south towards Moose Jaw on a smooth road, about 40 miles north and I decided to see what the little motor was capable of, since it shrugged off anything I had put it through to that point.

4th (top) provided 10 mph per 1000 rpm. My speedo and tach needles rotated clock and counter-clockwise, and the highest numbers were 12,000 rpm and 120 mph, both at the top of the gauge.

In the owners' manual it was said that the 9000 rpm limit should be observed except in top gear, where it was safe to go to any rpm so I decided, since there was a tail wind of about 20 mph, to see what speed I could reach. I was wearing a t-shirt, shorts and sunglasses (no helmet).
I tightened the friction on the throttle and on the steering head, turned the twist grip to full open, then put my feet on the passenger pegs, and steered by gripping the top of the fork tubes - all in the interest of streamlining. My speed climbed to an indicated 117 mph, which conformed exactly to the 11,700 rpm indicated. There was no sign of distress from the engine, so out of curiosity I let it run like this until I had to shut down for the approaching town (Moose Jaw). This was a distance of around 30 miles - flat out and doing 117 indicated in 80 degree temperatures.

When I arrived in MJ and drove through town, the engine behaved completely as normal, and when I started it next from cold again, it was as though nothing had happened. I was impressed.

By the way I remember the owners manual listing the horsepower as 28.5 (I remember because of the point five).

Russell

[LOUD MOUSE]

I see an additive named ZDDP which is advertised to stop camshaft damage with engines designed before 1989 while using the new oils.
Says it will keep engine parts (bearing and journal surfaces) from damaging each other due to metal to metal contact. .....................lm

running at 70mph for extended times can cause the engine to lock up momentarily due to cheap oil and pistons siezing. Run a good modern motorcycle "wet clutch" rated oil, and 60 mph all day is better for the bike. everyone will have a different opinion. Also remember that wear rates are dependant on rpms. ymmv. Modern oils have reduced wear, heat, friction, reduced piston scuffing, ring coking, cam and cam follower wear, cold start wear, and even mpg over the old oils. Engine life has been doubled with modern oils with higher lift cams, hotter engines, and higher pressures. High temp additives such a zinc and phosphates will actually be attracted to hot areas and cling to them, coat them and reduce friction. These additives do nothing till a part gets hots and then reacts so that they work only where needed. some owners insist on running the 1959 non detergent oi and are purist, but in 1959, no other oil existed and cars had valve jobs at 30,000 miles and overhauls at 50,000 miles with the low performing oils.

but so much for the oil commercial, short bursts of speed are great, all day cruising over 60 mph is a bit hard on this size of bike.

[Vince Lupo]

Hi! I'm new here.

I had a Superhawk back in 1966, when I was younger and even more foolish and a flying jets as a student pilot in the Canadian Armed Forces. This was in Moose Jaw Saskatchewan, where the roads are long, flat and straight and the winds tend to be strong and steady.

One time I was riding south towards Moose Jaw on a smooth road, about 40 miles north and I decided to see what the little motor was capable of, since it shrugged off anything I had put it through to that point.

4th (top) provided 10 mph per 1000 rpm. My speedo and tach needles rotated clock and counter-clockwise, and the highest numbers were 12,000 rpm and 120 mph, both at the top of the gauge.

In the owners' manual it was said that the 9000 rpm limit should be observed except in top gear, where it was safe to go to any rpm so I decided, since there was a tail wind of about 20 mph, to see what speed I could reach. I was wearing a t-shirt, shorts and sunglasses (no helmet).
I tightened the friction on the throttle and on the steering head, turned the twist grip to full open, then put my feet on the passenger pegs, and steered by gripping the top of the fork tubes - all in the interest of streamlining. My speed climbed to an indicated 117 mph, which conformed exactly to the 11,700 rpm indicated. There was no sign of distress from the engine, so out of curiosity I let it run like this until I had to shut down for the approaching town (Moose Jaw). This was a distance of around 30 miles - flat out and doing 117 indicated in 80 degree temperatures.

When I arrived in MJ and drove through town, the engine behaved completely as normal, and when I started it next from cold again, it was as though nothing had happened. I was impressed.

By the way I remember the owners manual listing the horsepower as 28.5 (I remember because of the point five).

Russell

Awesome. That must have been one heck of a ride!

I thought that the horsepower rating for the SuperHawk was 28.5 as well -- I think the 23hp refers to the 305 Dream.

I've done (and still do) extensive highway riding at speeds of 65mph+ and no problems at all, and I've put about 17,000 miles on the bike in about 6 years, including several 1000+ mile rides. Now I'm definitely no mechanic, but just my seat-of-the-pants experience has shown me that these bikes were made to rev, and these engines don't seem to start 'working' until 6000rpms. I'd think that it would be 'lugging' that would be bad for these bikes.

Of course, my bike's engine could blow up tomorrow, and then my opinions are out the window!

[LOUD MOUSE]

I think teazer said (rear wheel)!!!!!!!!!!!. ...........lm

Hi! I'm new here.

I had a Superhawk back in 1966, when I was younger and even more foolish and a flying jets as a student pilot in the Canadian Armed Forces. This was in Moose Jaw Saskatchewan, where the roads are long, flat and straight and the winds tend to be strong and steady.

One time I was riding south towards Moose Jaw on a smooth road, about 40 miles north and I decided to see what the little motor was capable of, since it shrugged off anything I had put it through to that point.

4th (top) provided 10 mph per 1000 rpm. My speedo and tach needles rotated clock and counter-clockwise, and the highest numbers were 12,000 rpm and 120 mph, both at the top of the gauge.

In the owners' manual it was said that the 9000 rpm limit should be observed except in top gear, where it was safe to go to any rpm so I decided, since there was a tail wind of about 20 mph, to see what speed I could reach. I was wearing a t-shirt, shorts and sunglasses (no helmet).
I tightened the friction on the throttle and on the steering head, turned the twist grip to full open, then put my feet on the passenger pegs, and steered by gripping the top of the fork tubes - all in the interest of streamlining. My speed climbed to an indicated 117 mph, which conformed exactly to the 11,700 rpm indicated. There was no sign of distress from the engine, so out of curiosity I let it run like this until I had to shut down for the approaching town (Moose Jaw). This was a distance of around 30 miles - flat out and doing 117 indicated in 80 degree temperatures.

When I arrived in MJ and drove through town, the engine behaved completely as normal, and when I started it next from cold again, it was as though nothing had happened. I was impressed.

By the way I remember the owners manual listing the horsepower as 28.5 (I remember because of the point five).

Russell

Awesome. That must have been one heck of a ride!

I thought that the horsepower rating for the SuperHawk was 28.5 as well -- I think the 23hp refers to the 305 Dream.

I've done (and still do) extensive highway riding at speeds of 65mph+ and no problems at all, and I've put about 17,000 miles on the bike in about 6 years, including several 1000+ mile rides. Now I'm definitely no mechanic, but just my seat-of-the-pants experience has shown me that these bikes were made to rev, and these engines don't seem to start 'working' until 6000rpms. I'd think that it would be 'lugging' that would be bad for these bikes.

Of course, my bike's engine could blow up tomorrow, and then my opinions are out the window!

[teazer]

Thanks LM. yep. That was from a rear wheel dyno rather than catalog HP which seemed to be measured "gross" on a good day.

I hear people quoting the graphs from a workshop manual or the advertised HP and those numbers are all crank HP and are usually adjusted (upwards) for transmission drag and without parasitic drag from the alternator etc.

Even a really good CB77 on a perfect day will struggle to pass 100 MPH and stock valve springs typically bounce at about 8,500. Sure, they can rev higher but it doesn't do a lot of good as a rule.

[Spargett]

Has anyone else encountered this?

running at 70mph for extended times can cause the engine to lock up momentarily due to cheap oil and pistons siezing.

[e3steve]

Yep.

We made it! 13 hours, 444 miles and one seizure......

And 'twas a regular occurrence in my former life as a 16-year-old in the early '70s.