sticky forks

[seanclarky]

I've rebuilt the forks on my 4l0 and one of them is a bit 'sticky'.  if you push it down to the end of the travel it doesn't pop back up every time.  I've stripped it down again and it looks ok, the stanchion doesn't look bent.  Any ideas what else could cause this?  cheers Sean

[LC_BOTT]

I had similar on a bike I bought as a rolling chassis, just didn't seem 'right'

First found out the stanchions were bent, and then found out the alloy bottom on one was bent too (only noticed this after buying new stanchions)

Was fine when I bought it, as everything was inline, after new seals etc was when I found out...

[JonW]

+1

[seanclarky]

ok cheers, I'll get the stanchion checked

[Deleted]

just roll the stanchion on a flat surface, say a table

you'll soon know if its bent

[seanclarky]

Feb 4, 2020 15:03:49 GMT 1 @hblair said:

just roll the stanchion on a flat surface, say a table

you'll soon know if its bent

hi, yes I did that and couldn't see any problems, if it is bent its only very slightly, I'm going to strip the other fork down and swap bits over to see if I can find the problem, thanks again

[midlifecrisisrd]

Rotate the stanchion in the lower a little at a time and see if it gets better/worse

Just if both are minutely bent and they are in different direction they will exaggerate the problem

Steve

[Deleted]

or put a straight edge on it at different positions and see if there are any gaps along the straight edge

[LC_BOTT]

You also need to check the fork bottoms as I mentioned, I've had three so far that are bent. If you're sure the tops are straight, remove the guts and slide the stanchions to the bottom for each leg, and that should point out what's bent. I also had slight wear marks on the stanchions where they had been rubbing. Rotating as mentioned and if bent you should feel them get tight.

[kostas]

I used pattern “extreme” seals when I rebuild mine and both were stiff from day one.

As soon as I fitted genuine Yama parts (the bag was Yama but the seals were NOK) it was fixed!!

[justyr]

Is it only sticking when on the bike?
If so, check yokes aren’t slightly bent. My understanding is that this is very common.

[seanclarky]

thanks for all the help guys, I'll have a look this weekend cheers

[Delbert]

I remember having this after having the stanchions rechromed, never really sorted it , but figured it never travelled that far when assembled with the spring, not saying its right but it never caused me a problem

[alankelly]

Hi

Yes I had this after Philpots rechromed the yellow project rd but found that rotating the stanchions in the sliders helps as there was a sweet spot where the binding went completely so just locked the stanchions / lower sliders in the yokes in this ideal position

I think like any sliding system the bore and the station are never dead straight so by rotating the two parts you are lining up the very slight mismatch

Hope you sort

Best wishes Al

[nokturnal]

Urgh mine seem to bind up a bit when fully compressed by hand, out of the bike.

They both do it. Like there are two stages...

Judging by the frame, it wouldn’t surprise me if they were bent too.

[alankelly]

Hi

I know it’s going of at a bit of at a tangent and never seen it before. But at the moment rebuilding a set of Honda forks from a 1981 CB400N and in 1981 Honda changed the design from the full stanchion sliding in the bore of the lower slider to having a standard fixed bush in the top of the slider and the bottom of the stanchion being fitted with another split bush (picture below) you only have sliding contact in two places rather than over the full bore of the lower slider



Never seen this before and looks like a good design to produce a fork with minimal friction

Only problem they are a real sod to disassemble as you cannot just undo the damper rod and pull out the upper as the lower bush will not pass the upper bush and fork seal due to the bigger diameter of the lower bush so upper bush and seal come out at the same time when up pull out the stanchion 😠😠

Catch up soon

Best wishes Al

[chrisg]

Try slackening the wheel spindle nut and see if it still sticks.