Author Topic: Rigid-framed Norton Dominators  (Read 3316 times)

Offline BJ

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Rigid-framed Norton Dominators
« on: December 19, 2011, 05:21:39 AM »
I am lead to understand that in the early '50s an entry requirement at Daytona USA was that the motorcycle had to have a production run of at least 200 units, be 500cc and in a rigid frame.

BSA campained in this class very successfully with their rigid-framed Gold Star & there is considerable historical data commerating their campaign.

Norton also campained with their rigid-framed 500cc Norton twin Dominator. It is more information &/or photographs of Norton's rigid-framed twins that I am attempting to unearth. Rumour has it that there is a B&W photograph in one of Norton Racing History books; but as yet it alludes me.

Can anybody out there shed some light on the rigid-framed 500cc Norton twin Dominator's campain at Daytona or any other race meet in USA in the early 1950's?. An image of the production model from the 1952 Norton (Export) Catalogue is attached.

johnnyboy-wonder57

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Re: Rigid-framed Norton Dominators
« Reply #1 on: January 19, 2012, 10:40:22 PM »
Hi,
There is a book by Mick Walker called Classic American Racing Motorcycles ISBN-85532-233-1, there's a lot of information on this era, the AMA banned Manx Norton's  around 1952.
 
 Other restrictions were  not allowing featherbed frames & restricted foreign motorcycles to lower compression ratios etc.
Rigid framed Dominators would have been 500cc or thereabouts, but would have been down on power compared to Gold Stars & heavier, I doubt whether they would have been competitive, again  too heavy & @29bhp  lacking in outright power, perhaps some Privateers raced them.

Cheers

JBW

johnnyboy-wonder57

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Re: Rigid-framed Norton Dominators
« Reply #2 on: July 25, 2012, 08:28:06 PM »
Hi,
Any luck, you never replied!
Just an update, there's a discussion on the NOC websire re-Domiracers of the 1960s also even though I poo-pooed them as possible race bikes in the early 1950s, the 29bhp @6,200rpm I quoted, was for a UK plunger- equipped suspension, Model 7 Dominator of 1951 a civilian mount.

You may have better luck contacting someone from, or that was employed by the Berliner Corporation @ that time, in the early to mid 1950s, they were the main Distributors in the USA for Norton products up to the industries collapse, some say, suicide!

Just as an example of what they would have been up against:

350cc Gold Star
1949  25 bhp @6,000 rpm;
1953 27 bhp @ 7,000 rpm;
1956 32.5 bhp @7,500 rpm;

500cc Gold Star:
1953 34.5 bhp @ 6,400 rpm;
1954  38.2 bhp @ 6,500 rpm;
1956 40.4 @7,000;   boosted to a possible 42/43 bhp with megaphone & a few mods;

Best Race Shop special:
350cc 37.5 bhp @8,000 rpm;
500cc 48 bhp @ 7,500 rpm both measured on a hydraulic Froude Dynamometer Type DPX, by Froude Engineering used to test all Gold Star engines from 5,000 rpm upwards @ BSA's premisis.



Cheers

John