New after market fork inner tubes preparation before assembly

[oldyzman]

Gday,
A mate has some new fork inner tubes to fit to his kawasaki, They seem very shiny. Should i run them in the lathe giving them a scuff of fine scotchbrite? Or? 

[Momus]

I've just had some stanchions  in the lathe going from 800 to 3000 grit to get them smooth and shiny for less friction and better seal life..


I'd leave them shiny.

[oldyzman]

yep,seems shiney but seems like it needs something else. just something not right about it? I am usually happy to leave well enough alone...

[Momus]

I know what you mean. You can have shiny but a relatively rough surface.

You want very smooth and flat and shiny....

[crs-and-rms]

you want the chrome legs  cross hatched like a cylinder less friction , smooth equals more friction

[oldyzman]

crs and rms
yep, the cross can hold a bit of oil too, me thinks

momus
agree too, want it flat also...

so use maybe 1500 the 3000 with some oil.....

[Momus]

Smooth equals less friction- surface asperities cause friction...

Hard chrome, properly fine ground, has a very shiny appearance and a very low Ra but is also lubricious because it has a microscopically cracked surface. 

 

[fred99999au]

So, on a similar bent (perhaps not the right term for fork legs, however) I am doing the forks for my IT200, but using the original stanchions with new seals and bushings, should I be doing anything other than cleaning them well and fitting them?

I have one leg chucked up the the lathe at the moment and need to get a bigger live center to secure it, but I was planning on using a fine paint cutting compound to clean the surface and then maybe a metal polish.

The stanchions seem largely nick free but have been up and down a few times by the looks.

[Momus]

Paint cutters is probably too fine for weathered legs. Start with  800 or 1000 grit wet and dry and soapy water and go up to 1500 or so.

I did this with some CR125 legs after straightening and despite plenty of rust pits the seals are behaving quite well.


You are in no danger what so ever of stripping the chrome from the legs