Norvin Weight

Little Honda

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Non-VOC Member
Many times in the past I witnessed discussions about the pro´s and con´s concerning Norvins. One of the better reasons against the convertion was always: "It´s heavier than the standard Vincent." Only today I decided to find it out. As I am assembling my engine at
present and are planning to better springing and damping of my Norvin, I wanted to find the correct values for spring rates and damping
front and rear. Therefor, I weighed my frame wheel by wheel with a good platform scale, by hanging the other wheel in its centreline.
Thereafter, I put my engine (cases with flywheels in) plus all other loose engine parts on the scale. Finally, the rest, consisting of silencer,
battery, footrests and some other small parts.
Result: Frame complete on wheels: front 50kgs, rear 53kgs
Engine (BS): 77kgs
Rest : 20kgs
Total dry weight : 200 kgs
Now you can compare this to any modern 1000cc- motorcycle, 4, 3, or 2-cylinder: not bad for a 53-year old bike, and: 6 kgs less than the
standard Rapide!
From my first riding experiences on it last year and from what I am expecting from the Maxton-modifications to the roadholders and girlings on the rear, I am sure, it will be a pleasure to ride!
 

davidd

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Nice Job! It is always good to have information at hand. Several years ago I ran across an article by Phil Irving doubting how the Egli could weigh so little when compared to the Black Lightning. Despite the fact that I love the stock Vincent, the Vincent wheels alone when compared to the aluminum Campagnolo wheels must have been double the weight. After riding the single racer for many years at 285 lbs. it is difficult to coax me back on a twin.

David
 

redbloke1956

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Non-VOC Member
Nice Job! It is always good to have information at hand. Several years ago I ran across an article by Phil Irving doubting how the Egli could weigh so little when compared to the Black Lightning. Despite the fact that I love the stock Vincent, the Vincent wheels alone when compared to the aluminum Campagnolo wheels must have been double the weight. After riding the single racer for many years at 285 lbs. it is difficult to coax me back on a twin.

David
Speaking of which David, I don't have any personal contact with anyone who races a Comet........How would the racing Comet compare in performance / handling to a standard Rapide/Shadow etc?

Regards
Kevin
 

vibrac

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Back when the VOC ran races and Vincents were used in Anger many said a good single could outpace a twin at Cadwell and they often did.
 

davidd

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The numbers are pretty good compared to a stock Rapide at 7 lbs per hp for the racer v. 9 or 10 for the Rapide. A little unfair comparing a hot Comet to a stock twin, but 42 hp with a big carb on the Comet will cause some trouble for the Rapide. The conering clearance is much better on the single due to the narrow engine bits. I would think the torque out of corners is great with the Rapide.

For most of our tracks over here, the straights are short, so the top end of the Rapide is a little higher, but harder to use. In current tuning, 103 mph at 7,000 is about the best I can muster. I think the Rapide will top that if there is enough time.

In the hands of a good rider the Comet would do very well on a tight track. Over here, Tom Kerr is still racing what was known as the "Flomet." Ken Genecco is racing the ex Dickerson Flash. They often come out for one or two races. There seems to be about as many European solo Vincent riders.

I have to say the Vintage riders were an incredible lot. The tires we use today allow very high cornering speed with little worry. Most of them would be unbeatable on a present day Vincent.

David
 
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bmetcalf

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Would a 54t sprocket help a twin on the track? That would give 106 mph at the same revs (5750) as 125 mph with a 46t sprocket. If 125 mph is drag-limited, a bigger sprocket could make for even better acceleration. Engine longevity would have to be considered, though. Is there a US class for Vincent twins? There wasn't one, except against much newer bikes a few years ago.
 

Bill Thomas

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The late Graham Treacher gave me a good thrashing, Me new to it on a twin and him on a fast Comet at Cadwell Park, He heard me slagging off Comets, I have now changed my mind !! I think it is down to the Rider, You put a fast bloke on anything he will give you trouble. Cheers Bill.
 

Howard

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VOC Member
Would a 54t sprocket help a twin on the track? That would give 106 mph at the same revs (5750) as 125 mph with a 46t sprocket. If 125 mph is drag-limited, a bigger sprocket could make for even better acceleration. Engine longevity would have to be considered, though. Is there a US class for Vincent twins? There wasn't one, except against much newer bikes a few years ago.

It really depends on the track. I used 3 different back wheel sprockets on my Comet racer (don't remember how many teeth) the smallest was great for Silverstone, but Cadwell's twists needed the middle one and the Three Sisters well........... the Three Sisters is different, there I used the biggest sprocket (54t I think) and never got into top gear.

As for twin vs Comet, again the track will have a lot to say. My Comet was no where near as fast as the Egli (road bike playing racer) at Silverstone, but they were a lot closer at Cadwell, at the Curborough Twisty sprint the Comet would just shade it, and as for the Three Sisters ......... the Egli in road trim wouldn't have stood a chance.

As Bill says the rider makes all the difference, but these are my recollections of my times on a road going twin and a race Comet.

H
 
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