[Ronny Grady]

I just changed the oil on my shiver. it is sooo much better, for the people who occasionally ask how to do it, here is the mack dady link:

http://inbred.gimpcupboard.com/manuals/SHIVER_DC.PDF

one question though, are the tiny allen bolts on top to bleed air? how and when do you do this?

 

[Dog Welder]

Yes it is to bleed air..and you do it really whenever you feel like it. For example in California to get to Big Bear you go through an elevation change of like 5000 ft. which will cause the air in your forks to expand...having something to do with less atmospheric pressure. If you don't bleed the air out it will essentially act as an "air Preload" making the fork not as responsive or plush. If you do it you should hear an audible fart coming out of those screws...just don't lose them.

 

[spoke80]

I just changed the oil on my shiver. it is sooo much better, for the people who occasionally ask how to do it, here is the mack dady link:

http://inbred.gimpcupboard.com/manuals/SHIVER_DC.PDF

one question though, are the tiny allen bolts on top to bleed air? how and when do you do this?

Thanks for posting the manual I really needed it. Since WV my fork feels like someone pooped in it.

 

[MikeD]

Yes it is to bleed air..and you do it really whenever you feel like it. For example in California to get to Big Bear you go through an elevation change of like 5000 ft. which will cause the air in your forks to expand...having something to do with less atmospheric pressure. If you don't bleed the air out it will essentially act as an "air Preload" making the fork not as responsive or plush. If you do it you should hear an audible fart coming out of those screws...just don't lose them.

This I have never ever understood, and I'll insist its wrong until someone can answer me how the air inside your fork knows about a change in elevation. The air inside your fork is the same at sea level as it would be in space, because it's in a rigid container that's not affected by the outside air pressure. Your air can't talk to the air outside the fork and find out that the outside pressure is actually lower.

If your fork was a balloon, the outside pressure would matter; the balloon as a whole would grow as the outside pressure diminished in relation to the inside pressure-but that whole scenario PROVES that the air inside a sealed container stays at the same pressure regardless of altitude, hence the balloon growing!!

So I think all the people who 'burp their forks because of an altitude change' are just feeling the effects of replacing the air in the fork with air of a lower pressure...which, I suppose, would make the fork more linear, no?

Anyhow, the shiver fork burp holes are there for a reason; I thought it was just that the inverted open-bath design swallowed air as the fork cycled and the trapped air messed with the tuning...so maybe it's not an altitude change, but just the overall burping that matters? How much pressure difference are we talking about, anyhow, at a mere 6-8000 feet above MSL? It's not like we're riding on Everest or something...

MD

 

[ioscope]

It does matter. When sea level air is let into the forks, it will be at 14psi. When you go to a higher elevation, the outside air "pulls" the fork sliders away from the stantions. This relationship will act inversely when elevation is lost.

It does matter in a closed container (which a fork isn't because it technically has a static volume.

Atmospheric pressure matters as shown by some german guy from the 1800's who did an experiment with two brass clamshell halves which he vacuumed and attempted to split them with two teams of horses, he was unsuccessful.

Obviously this pressure differential is nearly irreleveant in the troposphere where you will always be, since pressure varies exponentially which makes the lower part of the curve (troposphere) change pressure gradually.

Anyway, I agree with you, the fork pumps air as it cycles, increasing the pressure as you ride. So you should be bleeding every two rides or so!

 

[lovebunny]

id like to state for the record that my shiver feels no dif at bb than it does here in san diego


ps does anyone kno the last day snow summits open for bikes?

 

[ioscope]

Whistler goes thru OCt.