Front fork preload

[bikerphil]

Maybe Frank has caps....

http://www.frankmain.qpg.com/

[CaptonZap]

I have a Special with air caps. I just added RaceTech emulators, so I won't be putting air in the forks anymore. Any recomendations for plain caps?

Howdy Marty,
i have an 80G with the plain caps, and I would like to install air over caps. Would you consider a trade?
Thanks, CZ

[jetmechmarty]

Does anyone here have any indication why these parts might not swap? Will the swap change the preload for either of us?

[cywelchjr]

Special and Standard caps don't swap, the threads are different. And an 80G with non-air caps is non-original. The 80G came with air caps standard, so either the forks or the caps have been changed at some point, hopefully the forks as a whole as the non air setup uses different springs than the air setup as the air setup on the standards used weaker springs as part of the load was intended to be carried by the air unlike the earlier setup where the entire load was carried by the springs.

[jetmechmarty]

That settles that. Thanx!

[CaptonZap]

Special and Standard caps don't swap, the threads are different. And an 80G with non-air caps is non-original. The 80G came with air caps standard, so either the forks or the caps have been changed at some point, hopefully the forks as a whole as the non air setup uses different springs than the air setup as the air setup on the standards used weaker springs as part of the load was intended to be carried by the air unlike the earlier setup where the entire load was carried by the springs.

Wow, I'll check that out.
The caps have a chrome hex cover with an O-ring screwed into the sloped threaded holes, and since my regular bike has brass adapters for the air lines screwed into the same holes, I assumed that the air setup was an extra feature added at customer request. I'll check the thread as soon as the weather improves. CZ

[cywelchjr]

Wow, I'll check that out.
The caps have a chrome hex cover with an O-ring screwed into the sloped threaded holes, and since my regular bike has brass adapters for the air lines screwed into the same holes, I assumed that the air setup was an extra feature added at customer request. I'll check the thread as soon as the weather improves. CZ

Unscrew those, your will find an air fitting under there. Those are air forks. That's to keep dirt, water and other junk out of the air fitting and keep things nice and clean looking up top, but the air fittings are under that cover.

I'd give you a picture of what they look like with the caps on and off, but I'm not in a place to take the picture, upload it and then post it here (it's the taking it that I'm not in a position to do right now). But if you unscrew those caps, you will see what I mean.

[Poprock]

My SG has air forks. I run a Pacifico. Used to use 15 wt fork oil. Switched out to ATF and really like it. I think the 15 was hydrolocking. I run about 8-10 psi in the forks. XJ air shocks on the back, 30 psi if I remember right. Had to refill those and the spec is 5 wt, so I went with that. ATF might be too heavy there.

[jetmechmarty]

I believe lighter viscosity increases rebound.

Marty (in Seattle)

[Poprock]

I was concerned about that, but it isn't noticeable. Dive on braking was also a concern. It may be a little worse, but not much, and the ride is way smoother. Before I changed the oil and adjusted air pressures, it was pogoing over bumps and doing all kinds of strange things on curves. I run the tires at or near full inflate, 10 psi on the forks and 30 @ 3 on the XJ rear shocks. All the squiggles, pogoing and weird steering have gone away now.

[jetmechmarty]

The pogo bounce can mean the oil quantity in the fork tube is low. Oil does not compress and air does. Hence, the pogo bounce.

Marty (in Seattle)