Once you get that heavy flywheel and clutch spun up, all hell breaks loose and some times a gearbox or two.
Magazine road test of a 1972 Combat
- Thread starter Carl H
- Start date
- Status
- Joined
- Jun 30, 2012
- Messages
- 14,228
I went to a club sprint on an airstrip in about 1969. Most of the bikes were road racers. The fastest bike was a Super Rocket BSA at just under 13 seconds for the quarter mile. That is about what the fastest cars used to get back then. To me, it is irrelevant. What the bike does once it is mobile is much more important. If you beat somebody to the next set of traffic lights, what does it prove ? I rather find them on a back road and carve them up.
- Joined
- Jun 30, 2012
- Messages
- 14,228
When I first fitted the 6 speed box into my Seeley 850, I did not know I had the wrong selector drum. I rode the bike around the pits at Winton, but could not get it moving. So I gave it a heap of revs and slipped the clutch. I nearly stuffed the bike into the fence at the end of the pit road. I was probably in 5th gear and it really caught me by surprise. I never would have imagined the motor would pull like that. Try it some time - put your bike in third and give it a heap of revs by slipping the clutch, but make sure you have plenty of room in front of you.
- Joined
- Jun 30, 2012
- Messages
- 14,228
The weak point of a Commando has always been the gearbox. Fix that and you really have something which is unbeatable. The Commando motor usually spins up at the same rate regardless of the overall gearing. If the bike is under-geared the motor revs and the bike goes nowhere fast. It takes a four cylinder super-bike to beat a Commando in a straight line, and most do not handle as well as a Commando..
ashman
VIP MEMBER
- Joined
- Jul 11, 2010
- Messages
- 6,096
Al didn't you always say you never ride on the road, so how would you carve them up on back roads if you don't ride on the road.
- Joined
- May 5, 2017
- Messages
- 657
What year is that Classic Bike Guide article from?
Did that on a 500 Venom, went round a slow corner one gear higher, on the other side was a long downhill stretch going into another faster bend, bike flew like s*it!
But when I see some loud ass big money, big cu in HD at the lights, I used to light up the Commando, and show them, In case they didn't know,, They don't call em Commandos for nothing. I can't wait until my next meet and greet at the lights.
The 12 sec @ 114 MPH is very doubtful on a stock bike, Most times the top speeds are quite uniform even if the times vary by about a 1/2 seconds. With Big Red probably with a 21 tooth, I was just getting into 4th quite close to the end , Speed was 100 MPH most times. The speedo was accurate as it read the same. A top speed run on the highway was 120 MPH at 7,000.
I think that was 0 - 100 - 0 for the Cobra
http://victorylibrary.com/brit/norton-c.htm , Ok, I finally re found the Cycle World May 1974 850 Hop up. If you scroll down some you will see the CW hop up. with a Branch port and other hop ups. . One advantage they had with a 1974 stock bike was, It was fresh and did not have many miles. Big Red sold as a 1975 MK2a was suffering from the late model cam that when I finally took it out at 8,000 miles had 1/2 of a lobe worn off, But It turned as good a 1/4 mile times as ever right until the end.
Specifications
1965 Shelby Cobra 427VEHICLE TYPE
Front-engine, rear-wheel-drive, 2-passenger, 2-door coupe
PRICE AS TESTED
$7,000
ENGINE TYPE
Pushrod 16-valve V-8, iron block and heads, two 4-bbl Holley carburetion
Displacement: 427 in3, 6998 cm3
Power: 485 hp @ 6500 rpm
Torque: 480 lb-ft @ 3500 rpm
TRANSMISSION
4-speed manual
CHASSIS
Suspension (F/R): control arms/control arms
Brakes (F/R): 11.6-in vented disc/10.75-in vented disc
Tires: Goodyear Blue Dot, 8.15x15
DIMENSIONS
Wheelbase: 90.0 in
Length: 156.0 in
Width: 68.0 in
Height: 49.0 in
Curb weight: 2529 lb
C/D TEST RESULTS
60 mph: 4.3 sec
100 mph: 8.8 sec
1/4 mile: 12.2 sec @ 118 mph
Top speed: 165 mph
This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io
This one test from Car and Driver 1965, I've seen other tests that are similar.
I'm pretty sure there was a 0 - 100 - 0 which was around 12/13 secs 0-100 in 8.8 would make that a distinct possibilty
- Joined
- Jun 30, 2012
- Messages
- 14,228
Classic Bike , December 2020 Issue #491
A friend of mine told me ' If you have got a torquey motor, you don't need a close ratio gearbox'. I don't think he had ever used one. There is a substantial difference in acceleration as you come up through the gears. My Seeley 850 was hopeless when I had the normal 4 speed box. With the close ratio box it became much faster. Because of the high first gear in the 4 speed close box, I now have a 6 speed close ratio TTI box. I have never raced with it, so I don't know where the overall gearing will end up when I next ride at Winton . I've added a tooth to the engine sprocket. I think that with 6 speeds, I wiil be faster around the slower parts of the circuit and faster towards the ends of the straights, because the acceleration out of the corners determines how fast you go on the straights.
- Joined
- Jun 30, 2012
- Messages
- 14,228
I rode on public roads until I was 27, then went racing because the roads were too dangerous for me. Racing is much safer, even though the speeds are higher. When I was a kid I had several hotted-up 650 Triumphs and a very good Tribsa, over about 10 years. Every time I rode with my mates, it became a road race. You cannot do that in Australia any more.
The Tribsac was an A10 BSA frame with a pre-unit Tiger 110 motor and gearbox. It had 1963 Triumph fork yokes which helped it handle extremely well.
After I separated from my ex, my oldest son came to visit me. He had a ZXR750 Kawasaki and took me for a ride on the back. In one of our local roads, there is an S, bend which he rode through fairly quickly. When we got back to my unit, he said 'how was that, Dad ?'. I said 'very good Geoffrey'. I did not tell him how fast I had been through that bend After you get through it, there is a side street a bit further down. If any car had ever come out of there, I would have been dead. I would take it at literally the ton. I think I might have been insane
- Joined
- Jun 30, 2012
- Messages
- 14,228
A friend of mine had a 500cc Triumph Speed Twin which was quite fast. When he pulled it apart, he found the cam followers were worn hollow. He had them built up with Cobalite and reground. The bike was much slower after that. - (cam timing ?)
- Joined
- Jun 30, 2012
- Messages
- 14,228
When you compare bike and car speeds you are being silly. I am 80 and my friend is 1 month younger then me. He also used to race. These days he has a 1200cc Suzuki Bandit. Our wealthy people like to play at Portsea on the Mornington Peninsula and my friend lives halfway there. One of those yoiks had a go at him on the Mooraduc Road, with one of those extremely costly European super-cars. My friend made it go backwards very quickly.
They can corner faster than a bike.
They can corner faster than a bike.
DevonNorton
VIP MEMBER
- Joined
- May 7, 2015
- Messages
- 216
I have the 'Norton Commando, Ultimate Portfolio' book published by Brooklands Books referred to by Marineatlas.
This includes some road tests for Combat engined bikes.
Motorcycle Mechanics Super Test (pg 81-83) standing quarter 12.2s.
Cycle Guide 750 Roadster (pg 88-93) standing quarter 13.09s.
The legendary Norman White was the ace quarter-mile rider for Norton. According to Peter Williams in his book 'Designed to Race' it was Norman's 12.6s time that was in the brochures. In the States the best times their journos could achieve were 12.8s and 13.0s. So Norton sent Norman out. He ran 12.5s on his first run which was not believed so he ran a 2nd time and recorderd 12.2s. Job done! Peter's book goes on to say,
'Everyone at Thruxton was feverishly getting over the previous weekend's race 'disasters' and getting ready for the next, so Norman had to get the train and a taxi back to base. He walked in wearing a new stetson, and met none other than several times World Champion Phil Read, who congratulated him on his success and asked ‘How did you do it Norman?’ Norman replied with mock modesty, ‘Well, Phil, some people have it and some people haven't!’ Even Phil did not have an answer to that!'
This was 1972 and would certainly have been Combat-engined bikes.
Good times.
Andy
This includes some road tests for Combat engined bikes.
Motorcycle Mechanics Super Test (pg 81-83) standing quarter 12.2s.
Cycle Guide 750 Roadster (pg 88-93) standing quarter 13.09s.
The legendary Norman White was the ace quarter-mile rider for Norton. According to Peter Williams in his book 'Designed to Race' it was Norman's 12.6s time that was in the brochures. In the States the best times their journos could achieve were 12.8s and 13.0s. So Norton sent Norman out. He ran 12.5s on his first run which was not believed so he ran a 2nd time and recorderd 12.2s. Job done! Peter's book goes on to say,
'Everyone at Thruxton was feverishly getting over the previous weekend's race 'disasters' and getting ready for the next, so Norman had to get the train and a taxi back to base. He walked in wearing a new stetson, and met none other than several times World Champion Phil Read, who congratulated him on his success and asked ‘How did you do it Norman?’ Norman replied with mock modesty, ‘Well, Phil, some people have it and some people haven't!’ Even Phil did not have an answer to that!'
This was 1972 and would certainly have been Combat-engined bikes.
Good times.
Andy
- Status