Misc: Everything Else Series B versus Series C Machines

Texas John

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I have always operated under the belief that the differentiator between Series B and C machines was whether it came from the factory with Brampton or Girdraulic Forks. Even when looking through a number of Vincent books, there is frequent mention of Series B and C, yet the difference is never explained.
But is that correct - Brampton versus Girdraulic Forks? Were there other items that marked the difference between Series B and C machines?
A secret that everyone knows, apparently.
Thanks!
 

Simon Dinsdale

VOC Machine Registrar
VOC Member
VOC Forum Moderator
In the factory records the only difference between series B & C is series B machines had frame number R#### and Bramptons fitted where as series C had frame number RC#### and Girdraulics fitted.

All other changes like gearlever design, RFM length & design, HRD & Vincent crankcases and transfers were general changes that were subjected to both series B & C at the same time as there was an 18 month overlap where both B & C machines were made at the same time.

So basically yes its all down to the forks that were fitted when new and the frame number.

Simon
Machine registrar - VOC
 

Texas John

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Hi Simon,
Thank you. I forgot about the Frame Number change. I am glad I asked.
It being a very manual process, would you know if they ever sent out an RC stamped Frame with a Brampton front fork, or vice-versa, by accident?
 

TouringGodet

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I recall a story that Indian Sales special ordered a number of bikes to be fitted with Bramptons, some amount of time after Series B production had otherwise stopped. The factory supplied bikes with Bramptons. I don’t know how the frame number is stamped, but perhaps those were stamped RC?
 

Albervin

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When Girdraulic forks were introduced quite a few riders had their forks "updated" by the factory, There were some notable machines that raced in the clubman TT that had this "upgrade". If you had a bike with such history it would be a moot point to "restore" the bike back to original. Personally I would not as it would detract from the very personal history of the machine.
 

vibrac

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The new models were launched under the generic name ‘Series ‘C’’, when they were
announced at the 1948 autumn Motorcycle Show. Care should be exercised with the
word launched, as it should not be viewed in the mindset of the twenty-first century.
While at the show a new model was shown and announced, a complete new model
did not really supersede the old one. There was no new production line to be started.
Wholesale re-tooling did not occur. As explained, changes in specification continued
before and after that date, but the announcement of the Series ‘C’ does give a convenient
point to note the changes that had been made to the original Series ‘B’ specifications.

(The Vincent black Shadow)
 

greg brillus

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Aside all the smaller changes, of which there were many, the significant change was to the suspension. And most notably the upgrade to hydraulic shock absorbers over friction dampers. This would have been the major factor in the specification from a "B" to a "C" model. As great as they are the Brampton forks were very outdated by then, and the factory would have been busy trying to improve on them, especially as most other makes were using telescopic forks. Although not as ridged and strong as the Girder forks, their action and behavior has proven itself pretty hard to beat, and still the norm to this day.
 

Simon Dinsdale

VOC Machine Registrar
VOC Member
VOC Forum Moderator
I recall a story that Indian Sales special ordered a number of bikes to be fitted with Bramptons, some amount of time after Series B production had otherwise stopped. The factory supplied bikes with Bramptons. I don’t know how the frame number is stamped, but perhaps those were stamped RC?
As per every rule, there is the odd exception. Yes there are a couple of bikes that went to ISC that started as series C and the frame were numbered as such but it appears at the last minute altered to series B spec by fitting Bramptons.
The factory would grab any sale as they were constantly needing money so they would sell whatever you ordered.
 

Monkeypants

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I can imagine that riding at speed on imperfect roads would be quite an experience with original Bramptons, friction damping only.
The Girdraulics, with a decent shock fitted, aren't awful even after getting off modern bike such as the Thrux R with its anti-dive Showa big piston forks.
The Girdraulics will bottom now and then when pushed hard on a patchy road. Best to avoid that, however it does sometimes occur when fun is the goal.
The Girdraulics seem to take the abuse without a complaint.

Glen
 

passenger0_0

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Non-VOC Member
I can imagine that riding at speed on imperfect roads would be quite an experience with original Bramptons, friction damping only.
The Girdraulics, with a decent shock fitted, aren't awful even after getting off modern bike such as the Thrux R with its anti-dive Showa big piston forks.
The Girdraulics will bottom now and then when pushed hard on a patchy road. Best to avoid that, however it does sometimes occur when fun is the goal.
The Girdraulics seem to take the abuse without a complaint.

Glen
Completely agree with Glenliman, I frequently have to stand my bike up and roll off the throttle after encountering corogations on corners. We have some rough roads in NZ and losing all steering with the front wheel bouncing frantically up and down is no fun. Dangerous infact. While I want to keep my Series B with Bramptons as standard as possible I need to either slow down or buy one of those nice coil over shocks.
 
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