I believe (prompted by the guy from Fork English 🙂 ) that the stanchions on my Pace forks are too smooth and shiny. If they had a slightly rougher finish I think they would hold onto oil better and hence the fork action would be better lubricated.
So the question is, how best to take the sheen off a hard surface? Clearly I don't want to sand my stanchions.. I was thinking more like using some kind of coarse polishing compound, or Jif/Cif or something. It would have to be super fine though since I don't really want to remove any material to speak of. What do they use for making frosted glass?
Are you insane?
Surely they have a oil sponge underneath the seal which holds onto the oil. I would get some professional advice before taking polishing compound to a pair of £££ forks.
It's a new one to me, having stanchions that are too shiny. Are you sure?
Do they slide better in one direction than the other?
WTF?
Then again... Rock Shox did ti nitriding on 2001 SID Races, then 'Slippery Silver' coating on their forks for a couple of years before reverting to the previous bronze coloured finish. Allegedly it reduced stiction, but obviously had other negative effects too.
is this a troll?
they would leak.
would you keep oil in a bowl or a collander?
Are you insane?
This is already well established.
Look, I am asking how to unpolish hard surfaces. I'll attempt what I feel like attempting 🙂
They woudl not leak. I don't want great big gouges in there (which is why I am asking this). They wouldn't leak any significant amount.. after all other people's stanchions are made this way. Apparently DT made the stanchions less smooth when they took over.
ummm... sandpaper, I reckon. Seriously. Maybe start with wet&dry paper to see if it's rough enough, then gradually work up to the rougher stuff.
No way sandpaper. All I want is a matt finish. Just enough to cloud the surface.
[url= http://www.axminster.co.uk/product-Hermes-Wet-and-Dry-Waterproof-Silicon-Carbide-Sheets-19877.htm ]very fine wet and dry[/url]
is what you might need if you're determined to go ahead - the higher the grit the better. it'll be difficult to take an even amount off the whole way around the stanchion though.
My only question is how will you know when they're rough enough?
[b]Apparently[/b] DT made the stanchions less smooth when they took over
And there is the Caveat !!
As suggested, if you want to have a go buy the finest wet and dry you can
My only question is how will you know when they're rough enough?
When they look matt.
green scotch pad if you're really going to do this 😯
Some light shot peaning is what you want surely?
This can only end in tears...
😉
He's dead right though. In a many applications a slightly less than smooth surface provides a longer lasting and lower friction surface for the reasoning given.
It's a brave chap who tries it though 🙂
hang on...
if the guy from Fork English is recommending this what technique does he recommend?
i wouldn't advise it but either jewellers polish or toothpaste (v fine abrasive) polish it with a polishing cloth.
I really think you will struggle to do this. it is easy to make them with a less flat surface finish, as you have said dt did, but to take it back, by hand, and do it well almost impossible i'd say.
Fine emery paper used oiled - work it at 45 degrees to the stanchion for perfect cross hatching. I have used this to polish scratches out of hrd cromed motorbike stanchions. However I wouldn't touch coated alloy MTB stanchions with anything abrasive
if the guy from Fork English is recommending this what technique does he recommend?
Ok let's make this absoutely clear. Fork English guy was ABSOLUTELY NOT RECOMMENDING IT! I in no way want to get him into trouble!
He told me that DT had made their stanchions less smooth to make the fork plusher for the abovementioned reason. I thoguht I might try it because I am crazy, and I want some Magura Durins anyway.
It's along the same lines as honing cylinders and brake cylinders in engines:
"When a bore has been run in, all the peaks will have been cut or worn off, leaving the honing grooves. These grooves act as oil reservoirs for lubricating the bore and spreading the oil round the cylinder wall as the rings pass over them"
Take a look inside the air chamber in your forks. You'll see loads of grooves on the inside.
I have used this to polish scratches out of hrd cromed motorbike stanchions
See, that's removing a significant amount of material. I don't want to take that much off. I am talking about roughness on a microscopic level - like frosted glass.
Course - the other option is to try and do it to the seals. But that's a much more difficult material to work with.
are you smoking crack?
My only question is how will you know when they're rough enough?
It'll be just before all the oil p1sses out over the floor. Stop sanding just before then.
Nick - "but obviously had other negative effects too"
Yes - It rubbed off really, really easily!
GB
From previous contacts with a few industrial clients, I know a lot of manufacturing processes use acid and alkali surface treatments. Worked with a brake caliper manufacturer who used to do a lot of these sort of surface treatments - ie a chemical etch of the metal surface, instead of a physical, abraded tretament.
How the hell that could be done away from a dip bath, or indeed done safely, I have no idea. DO NOT TRY AT HOME caveats apply.... But, IF you knew some contacts in the metal plating industry, they might be able to try it for you.
As others have said - best left well alone IMO
When a bore has been run in, all the peaks will have been cut or worn off, leaving the honing grooves. These grooves act as oil reservoirs for lubricating the bore and spreading the oil round the cylinder wall as the rings pass over them
Not sure that's a good example as engine pistons use metal rings to create the seal not soft bits of foam. And the honing AFAIA is done to create friction between the rings and the cylinder bore and thus create a better gas-tight seal.
If this method worked why isn't it done by anybody as standard?
Anyway, it's an interesting thought, let us know how you get on.
Go for it, and let us know how it turns out. Brilliant.
If your stantions are too smooth to live with, why not sell the forks on for £££ now, and get something rough enough for what you're after, instead of trashing these and having to buy something else afterward?
Maybe you should speak to Tefal and find out about getting them teflon coated. Certainly works on my frying pan, the eggs never stick!
If your stantions are too smooth to live with, why not sell the forks on for £££ now, and get something rough enough for what you're after, instead of trashing these and having to buy something else afterward?
Not a bad idea - tell you what, I could do a swap....
... somewhere in the spares box I have a pair of 1996 RST 381s (?). I know for a fact that the stanchions on those are as rough as rats..
I thoguht I might try it because I am crazy,
Zany as well I imagine.
Dont bother, you dont have rings sealing your pistons so honing wont help. You want to fix the problem, not patch a solution badly.
My marzocchis are buttery smooth and shiny as your best silver. It's a fault elsewhere, not with oil holding.
I suppose you could try something fully synth engine oil (tends to stick to metals) instead of fork oil, but I couldnt be sure it wouldnt react with your fork metals.
Service the fork and make sure the wiper under the main seal is saturated with oil. Lidl has some silicone spray for about £1 this leaves an invisible layer that is dry to the touch but is slicker than a greased pig. Mangle your forks with emory paper if you want but you'll wish you hadn't.
As others have said - best left well alone IMO
I'm not stupid. Really, I'm not. You just think I am because you aren't really understanding what I am getting at, and you therefore assume I am thick and going to do something really brainless. I like to fix things, but bearing in mind the above I am not going to bugger up my forks.
you dont have rings sealing your pistons so honing wont help.
Ehh? I am not going to bloody well HONE them, I mentioned that it was a similar idea!
Mangle your forks with emory paper if you want but you'll wish you hadn't.
This entire thread exists because emery paper is EXACTLY WHAT I DO NOT WANT TO USE! Good god you people aren't half thick sometimes! Try reading the thread properly! 🙂
If this method worked why isn't it done by anybody as standard?
It is, I think - by DT as mentioned above. And shiny metal isn't all that smooth - quite possibly rougher than the shiny coating on my stanchions.
The forks currently are very smooth in movement, but what happens is that after a few seconds of non-movement they stick, and stop responding to small bumps until you hit something bigger. It's almost as if.. there's no oil film between the seals and the stanchions. Now, if only I could find a way of getting oil to stick to the stanchions it would be much nicer. Maybe a very slightly rougher surface finish would help?
Why not mail DT and to see if they will tell you how they do it?
Rub them with a copy of the Angling Times?
Now, if only I could find a way of getting oil to stick to the stanchions it would be much nicer.
Sounds like an internals issue to me and I very much doubt the dust seal is removing ALL the oil from the stantion making it sticky.
Have you tested this by simply wiping the stantion with fork oil and seeing if that makes a difference? Put plenty on and see how much the dust seal takes off.
If it does improve the action then I'd be looking under to dust seal to see if the foam seal is applying oil properly to the stantion.
Alternatively push the dust seals up to the top of the stantions (off the lowers) and see what the action is like. If it's still sticky it can't be the dust seals/lack of oil on the stantions causing the problem.
If you need a fine abrasive paper,try lapping paper, http://workshopheaven.com/cgi-bin/cp-app.cgi?usr=51F8460052&rnd=6269509&rrc=N&affl=&cip=195.137.61.17&act=&aff=&pg=cat&ref=Scary+Sharpening&catstr=HOME:Sharpening these are really fine designed for the ends of fibre optic cables.
Ian
P.S. If you're determined to do this,I have a couple of half-sheets that I use for knife sharpening,you can have one if you want.
(I wouldn't touch it with a bargepole face)
Ian
I had some motorcycle forks rechromed. They are then ground to size after rechroming and not polished - exzactly for the reasons on this thread
Molgrips - oiled emery is about as fine an abrasive as will give you what you want IMO
try a scabbler on them, that'll un-polish the surface for sure! 😉
Right seeing as you are serious this is what i would do, first take out some kitchen roll/bloting paper when you next ride the bike to find out if there really is no oil on the uppers.
So lets assume there is no oil on the stanchions, give them a full service by the book getting loads of fresh oil on the sponge thing below the seals. See if that works I would hope so.
But lets assume it does not work. I would go to your local fabric shop and buy some leather not much lets say a foot square (they'll probably sell it in metric) Right now get some tooth paste I remember arm and hammer being more pastey, but any should do and put this on the stanchions or leather (you'll have to take the fork apart) now rub them you'll soon find a method that works.
I use this as my second to last process when sharpening chisels or hand planes, but as your stanchions are highly polished already this should do the reverse and do as you want. If you want a grinding compound either go ask at your local polishers or a quick google brought up grounded pumice stone and petroleum jelly, which sounds great.
"tell you what, I could do a swap....
... somewhere in the spares box I have a pair of 1996 "
I was thinking more along the lines of buying a new DT fork (as this is apparantly sufficient? and selling the DTs
"He told me that DT had made their stanchions less smooth to make the fork plusher "
"It is, I think - by DT as mentioned above. "
Are you sure DT just don't make them a touch less smooth? Rather than make them too smooth and then have to make them rough enough? (apologies if I've not read it fully)
Are you sure DT just don't make them a touch less smooth?
Well obviously they do. However I don't have access to a DT fork making factory so I was investigating the possibility of achieving a similar result through other means...
Buying a DT fork is a great idea except that they are £750 🙂
As for the fork internals - they have just been thoroughly serviced by the lovely Fork English bloke. They are stored upside down normally so the wipers are lubricated. If I oil the stanchions (tried loads of different oils) not much happens. Water does bead on the stanchions but that's about all the evidence I see.
Interestingly, I have another pair of Pace forks, RC39, which appear to have a similar coating on the stanchions (they are the same year). However these are always superbly smooth and active, and there clearly is more oil on the stanchions; it bunches up at the top of the stroke and attracts dirt etc, which doens't happen on the RC41s. So something's different.