Turcite fork bushing update

Its been about 6 years now and approx 30,000 miles with these Turcite fork bushings. I'm upgrading my dampning and renewing the seals and took some photos of wear marks on the Turcite. I was surprised to see how little wear there was.

The lower bushing below shows almost no wear - the original machine marks are still evident. This was the 1st (prototype) set I made and they were hand turned (not CNC), so you see more lines in the machining. This is the disc brake side.


The inside of the upper bush below shows only a little darkening near the top. The rest of the bushing is nearly untouched. By comparison my old bronze bushes show vertical lines and wear marks.


No metal to metal contact means everything is slippery. No wear on the steel fork tubes either.

I'll try to post the dampner upgrades later (modifying stock components only).

Whats it doing to the bottom slider ?

What's the spacer in between the bushes?

Its to act as a top out aid, it fixes a design flaw in the forks where the topping out is performed by the damper valve hitting the top of the damper rod, it changes it to the original anti topping out aid by covering the holes in the bottom of the stanchion earlier and trapping a small amount of oil to act as a buffer instead of meta to metal contact.

Is the long top bush part of what was originally referred to as the Covenant conversion?

Jim, instead of the metal spacer tube, are longer top bushes available in Turcite? It would appear to be a further improvement to the good results you have already listed.
If available I would buy a couple of sets tomorrow.
Cheers
Rob

Is the long top bush part of what was originally referred to as the Covenant conversion?

Click to expand...

Yes, it must stay up on the bottom of the top bush to work properly, if it is not a snug fit in the slider it ens up sitting above the bottom bush and the holes are permanently blocked giving you another problem, so long bushes work better.

That was my confusion. Maybe Jim could enlighten us?

The aluminum spacers do eliminate the top out problem. To keep them in place they are slit and expanded in diameter a little so they push into the slider by hand. They don't move and everything keeps working as it should. You can see the slit in the photo below. Its just an easier way than machining longer top bushings which aren't needed in Landsdown dampner kits.

I'm not seeing any wear inside the bottom sliders either.

To utilize with the landsdown kit then you don't need the metal spacers just the bushes?

@Jungle_re correct.



I asked the same question of John Bould back in the day, and he confirmed the 'Covenant' method of blocking the holes was not needed with his damper conversion.

gtiller said:

@Jungle_re correct.

View attachment 6796

I asked the same question of John Bould back in the day, and he confirmed the 'Covenant' method of blocking the holes was not needed with his damper conversion.

Click to expand...

It depends on when the Lansdowne dampers were made.

Lansdowne dampers purchased after approx Oct 2010 may already have top-out protection and should not “clunk” harshly at full extension. You should add the JS aluminum sleeves and set screws if you have the early Lansdowne damper version in order to soften “top-out”.

You only need the setscrews if you have aluminum sleeves (with stock or early Lansdowne dampers).

But if you put them in the later versions it won't hurt anything.