Short Norton Roadholder Forks bends

Little Honda

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Non-VOC Member
Hi all, I am worried about the flexibility of my roadholder forks. Mecanically, it is all done, no unwanted clearances, anywhere. But, if I take the frontwheel between my knees to keep the front
wheel in position, it is possible to turn the handlebar by more than 1/2 in to both sides. Looking down the forklegs, it is clearly visible, how they twist.
This weekend at the Schotten races, I did the same to the 2 present John Player Nortons, and another Manx in the paddocks: The same!!!
This might be ok with a 120kgs racebike, but I wonder if it can do its job in a twin-norvin!
Come-on, Norvinners, let me know your comments!
I was worried to observe the same on famous racers and went to a 500 cc BMW racer with telescopic forks of the period. I know from my BMW days, that these forks are not the best, but I
wanted a comparison. Result: They twisted much less than the roadholders!
My forks have new stanchions, new precision-machined bushes to match my re-bored forklegs, and
all screws are deadtight.
:confused:
 

Peter Holmes

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VOC Member
I am unable to help with a solution for your flexi forks but I think Irving and Vincent were aware of the problems, see page 29 of Know Thy Beast!
 

roy the mechanic

Well Known and Active Forum User
VOC Member
as i remember you need a fork brace. a peice of 3/16 (4-5mm) alloy bolted to the two mudguard mountings inside the fork sliders ,extend this to fit two cross tubes to match the other side over the top of the tyre, use 5/16 (8 mm) cap screws to join the sides together . fritz egli used to sell them .look for period photos to see how it was done.
 

Bill Thomas

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VOC Member
Hello Little Honda, I fitted Norton forks to my Special mid 70s, No Brace, Steering a little slow but always felt safe, It is a road bike that I raced and was timed at over 140 mph, Went off the track a few times but never fell off !! Good Luck Bill.
 

Little Honda

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Non-VOC Member
Thanks, Pete, I think, you mean page 24 instead! If PCV checked roadholder forks in comparison to his Girdraulics, he must have been very convinced of the Vincent solution, indeed! I doubt, that a forks strengthening bridge, fitted
to the 1/4in bolts of the fender holders, would last long in their threads. Stanchions with greater wall thickness seem more promising, if it is to stay original.
I shall try it out first, cautiously, and shall find better forks, if necessary. Peter Volkers told me on the Dutch this year: " It looks better, than it goes!" Not my point. If it looks good, it must ride as well!
cheers
 

Peter Holmes

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VOC Member
Thanks, Pete, I think, you mean page 24 instead! If PCV checked roadholder forks in comparison to his Girdraulics, he must have been very convinced of the Vincent solution, indeed! I doubt, that a forks strengthening bridge, fitted
to the 1/4in bolts of the fender holders, would last long in their threads. Stanchions with greater wall thickness seem more promising, if it is to stay original.
I shall try it out first, cautiously, and shall find better forks, if necessary. Peter Volkers told me on the Dutch this year: " It looks better, than it goes!" Not my point. If it looks good, it must ride as well!
cheers
Without wanting to appear pedantic it depends on which edition of KTB you own, in my original 1972 edition the quote as you correctly point out is on page 24, whereas in my 1989 edition it is on page 29.
Peter
 

Howard

Well Known and Active Forum User
VOC Member
Hi all, I am worried about the flexibility of my roadholder forks. Mecanically, it is all done, no unwanted clearances, anywhere. But, if I take the frontwheel between my knees to keep the front
wheel in position, it is possible to turn the handlebar by more than 1/2 in to both sides. Looking down the forklegs, it is clearly visible, how they twist.
This weekend at the Schotten races, I did the same to the 2 present John Player Nortons, and another Manx in the paddocks: The same!!!
This might be ok with a 120kgs racebike, but I wonder if it can do its job in a twin-norvin!
Come-on, Norvinners, let me know your comments!
I was worried to observe the same on famous racers and went to a 500 cc BMW racer with telescopic forks of the period. I know from my BMW days, that these forks are not the best, but I
wanted a comparison. Result: They twisted much less than the roadholders!
My forks have new stanchions, new precision-machined bushes to match my re-bored forklegs, and
all screws are deadtight.
:confused:

Hi Arnie :)

You got me thinking, so I tried to twist my Metal Profile forks, and I can't move them, so either my MPs are much better than Roadholders (which I doubt) or you're much stronger than me (which I don't doubt). Don't forget 1/2" at the handlebars is a lot less at the wheel spindle.

I'd be inclined to forget it and ride the bike. Roadholders are a bit long in the tooth, but I don't remember a lot of compaints about them over the years.

I'm not sure, but I think the fork braces mentioned were intended to make the sliders go up and down together, not to stop them twisting - I may be wrong, I've never used them.

H
 

roy the mechanic

Well Known and Active Forum User
VOC Member
Little Honda, a 1/4 inch bolt can withstand a pressure of one imperial ton. they will accept the braking forces of the most powerful brake the world has ever seen(the Yamaha 210mm from a tz racer) . I know this from personal experience. Go away, do as you are told for once in your miserable existence, make a fork brace , then tell me I am wrong!
 

Little Honda

Well Known and Active Forum User
Non-VOC Member
come on, splendid mechanic, fix one metric ton on a 6mm bolt, being held in an aluminium thread, and lift it!
Good luck!:cool:
 
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