I hate stainless steel :-)

[oexing]

18/8 or 18/10 is short for 18 percent chromium and 8 or 10 percent nickel, in your country called 304 or the like. DIN number is 1.4301 so no troubles to get anywhere. The easy machining type 1.4305 got a bit of sulphur in the alloy, don´t know this type in AISI standard but somebody here will know. No worry about using them on girder forks as the Spares Co most likely got same types for spindles. I had discussions in other forums with scaremongers wanting to tell it was risky to use on girders but in fact shear strength is way higher than what you ever will feed into the girder. Before literally hitting near to shear strength for spindles you will have a flatted tire, springs on block , spokes broken - and yourself catapulted into the greenery . . . .

Vic

 

[Martyn Goodwin]

True, but Vic, it's not hard coming, that's a plating process.
This is by diffusion, or something like it.
www.chromin.nl

BTW, I've got me a full set of titanium grade 5 and metric nuts, to play with.
I could not get BS ones....
The bike needs to shed bit more weight:
I myself can't loose any weight any more, and I want to be faster than @erik , as he is slimming down very fast nowadays.

Taken 10kg off my Comet over the last 6 months - all without touching the bike!

 

[Magnetoman]

Having forks collapse is too serious of an issue for me to offer technical advice, but I'll just say that anyone planning to replace a stressed component with a different material should carefully look into fatigue cracking of the replacement material, which occurs for many materials well below the shear strength.

 

[oexing]

Jut to see some numbers for girder forks , the springs will most likely be on block way below one ton (1000 kg) load from the wheel/road forces. The cross section of lower spindles is about 11 mm (7/16 ?) in the thread root . So when taking only 50 kg/mm2 tensile strength minimum for stainless 1.4301 it is 30 mm2 cross section , times 50 makes 1500 kg . Shear loads is 0.7 x 1500 , so it is 1060 kg per side. Both ends will take over 2 tons shear load. With typical road forces you will very unlikely get any fatigue I´d think.
Sizes of girder spindles were not calculated because of shear loads but for plain bearing load in the greased bushes with spindles.
Fatigue is a big factor with aluminium at high loads, it never "forgets " earlier high stresses. Some will know alu conrods will be replaced at periods in racing, otherwise you´d risk very bad language and costs when not taking care of replacing in due time. But steel is a lot safer in long use and in mild load use no limits at all.
The Spares Co sells stainless spindles for years I think and I have not seen reports about any troubles. For getting rid of greasy corners I suggest pairing ss spindles with high tech low wear lubefree plastic bushes like from IGUS, some more brands there from elsewhere I believe. Even concours judges will not have a chance to know about these - apart form finding no grease traces anywhere . . . .

Vic

 

[highbury731]

Having forks collapse is too serious of an issue for me to offer technical advice, but I'll just say that anyone planning to replace a stressed component with a different material should carefully look into fatigue cracking of the replacement material, which occurs for many materials well below the shear strength.

ClevTrev is very keen on Girdraulic fork spindles being made of martensitic SS instead of austenitic

 

[vibrac]

The Spares Co sells stainless spindles for years I think and I have not seen reports about any troubles. For getting rid of greasy corners I suggest pairing ss spindles with high tech low wear lubefree plastic bushes like from IGUS, some more brands there from elsewhere I believe. Even concours judges will not have a chance to know about these - apart form finding no grease traces anywhere . . . .

Vic

Ah a six year old question

Girdraulic Grease nipple fitting locations

Hello, Could someone direct me in the right direction please in regards to fitting grease nipples to the links on the Girdraulic front suspension? I tried to find this information on the site but I must be using the wrong terminology. In "Know thy Beast" E.M.G Stevens says to fit nipples to the...

www.vincentownersclub.co.uk

Plastic bushes nobody wanted them what a pity

 

[Gordon Ryley]

Not knowing any better than to serve as a concours judge, being so foolish as to want an as-original Vincent to ride, and disliking bead-blasted SS despite its perfect resemblance to cadmium from 6 feet away in dim light. Forgive me, I know not what I do.

 

[Gordon Ryley]

As Gregg says it makes him smile.the first Vin I ever saw 1946-7 the owner was
polishing it the seeds were sown it was all shiny so when my time arrived for my
first bike it had been resting a few years exposed to the elements. so rusty nuts
& bolts little round & loose no sockets or ring spanners or Mole grips 1952-3.
Buying nuts & bolts they were not very good you painted them black but if you
had access to aircraft quality bolts then as standards rose you would turn the
item no of the head of the bolt give it slight dome effect your pal would get it
come plated your off its an character flaw in some of us.Blonde or Brunette,
Allen head or Cheese head S/S or Crome. just going out on my Electric Vin,
Black Prince.they will never know. Walter Mitty alias Gordon Riley

 

[Bill Thomas]

I did the black paint on nuts, In the 60 s,
Not Nice !.
Cheers Bill.

 

[oexing]

Sorry, folks, my calculations above late night were crap. I did not factor in the pi 3.14 in the cross section of the lower spindles so in the end shear load per side is about 3.3 tons, almost 7 tons both ends. BUT all loads are contained in the fork springs and not transmitted by spindles - unless you hit a pothole and the fork hits its stops. At zero trail and rake you´d have no loads in spindles except for roadholding the fork. With trail and rake you get maybe 100 kg per side load for each plain bearing, nothing in way of doubtful stresses in spindles. Someone may do vector force maths in girders if interested but really this is no factor for worries.
As to bushes in girders, for girdraulics - not my business - maybe someone could try some IGUS or Permaglide bushes. I would, as no grease is required and no rust with stainless spindles a consideration. That minimal friction should not be too bad as you want some damping in the hydraulics anyway, so a fraction of this may come from bushes with no bad effect ? The IGUS material J can be had in rounds for turning up any size you need and after pressing in undersize you can line-ream to no-clearance pushfit fit with spindles. I would not want mini ball bearings as available for some mods. Water can rust them up and ball bearings may just overgloss misaligned fork components with no obvious friction from this. Well, thread drift again . . . .

Vic