Problem with F2 fork internals

[jimblob]

Hi guys,

I’m hoping someone can advise me on an issue I’m having with my fork rebuild on a rd350r YPVS (1995).

I’m fitting renthal bars and have obtained the lc2 top Yoke, lc2 stanchions, new seals/bushes etc. and I was hoping to keep the f2 fork lowers.

I’ve just started putting it all together and discovered the f2 damper rod
will fit inside the lc2 stanchion but once I fit the rebound spring and/or the nylon piston ring to the top of the damper rod it won’t fit down the lc2 stanchion.

Would it be easier to obtain a used lc2 damper rod and rebound spring or if they are hard to come by would I be better off getting shorter f2 stanchions made. The original stanchions are rusted/junk.

Any suggestions and potential solutions greatfully received.

Cheers

Jim

[midlifecrisisrd]

Are the LC2 stanchions new

The reason I ask is I have had issues before with aftermarket stanchions and the damper rings not fitting. It's like the tubing has a slightly smaller ID

In the past I have taken a small file and carefully trim the damper ring ends till they fit

Steve

[jimblob]

Hi Steve,

Thanks for your speedy response.

Yep, you’re right. They are new stanchions and the ID seems to be slightly smaller by a tiny amount.

Is it the outside edge of the flattened end of the rebound spring that I should file or just the plastic damper ring until it slides into place.

Even the F2 fork spring won’t fit down the lc2 stanchion so does that mean even an lc2 fork spring won’t fit either!!!

Thanks again

Jim

[midlifecrisisrd]

I just filed the damper ring.

It wasn't ypvs forks so no more experience I'm afraid

Don't know if F2 and lc2 springs are different I'm afraid

Steve

[jimblob]

Cheers Steve.

I think it’s gonna be the ID of the stanchions that are to blame. I can’t imagine the lc2 and f2 fork springs, rebound springs and damper piston rings are all a different diameter!

I’ll do some more digging.

Jim 👍

[elsiefan]

When I rebuilt my 4L0 forks, I had new stanchions and damper rings, and they were a very tight fit in the tubes. I couldn't get them in at first and like you, wondered if the tubes ID was a touch small, though with some judicious jiggling, some fork oil as lube and using thin feeler gauges to push and ease the damper rings in place, I got them in without any filing.

[jimblob]

Thanks for the info elsiefan. I’ll give that a try with the damper rings.

I’m really scratching my head about the rebound spring and fork spring not fitting though. I might try carefully filing down the outside edge of one of the old fork springs where it’s been flattened at the end. See if I can persuade it to fit.

Cheers

Jim

[jimblob]

I’ve just been in the garage to have another look at this.

I think the plastic damper rod piston ring would give a bit and fit with a bit of jiggling/persuasion but there is no way the small metal rebound spring or main fork spring will fit inside the lc2 stanchion. It’s as if the ID is 1-2 mm too small.

Does anyone know if the lc2 and f2 fork springs have the same external diameter.

Cheers

Jim