Packing your bike. : LUSENET : Mountain Bike Hash Forum : One Thread

This is not a question, but a rather interesting answer to a question I asked during the Kiara Bike Clinic...this was taken from Ask RC page in MBA mag.

Q. Oh Guru-of-infinite-Knowledge, I wish to take my bike with me on a trip (by plane). Must I make any special efforts with my SID XC fork, or SID rear shock. Both are air suspension and I am concerned about the air pressures in the cargo hold of the plane. Please bestow your wisdom upon this lowly wretch. -Brian- - 8/6/00 10:52:39 PM

A. Lowly Wretch, Fear not. Your air suspension will not be overtaxed by the lower pressures at 35 thousand feet. The hold is actually presssurized in jet liners, although it isn't well heated. RC

-- Matt (, August 23, 2001


I spoke to a couple of mtbikers who r aircraft maintenance engineers regading the matter. They say that the aircraft is pressurised to 13000ft. So if u pump your shock to 70psi, the actual pressure when u r up there is greater. Furthermore, drastic descents or ascents could also affect the pressure of the shock. Better to be safe than to find out upon arrival that the shocks r busted.

-- IceCube (, August 27, 2001.

My thoughts exactly. It's not like you can sue Richard Cunningham if your SID blew at 35,000 feet. Better safe than sorry. Besides, my own experience with SIDs is that they're high maintenance and rather fragile. I blew the (non-rebuildable) cartridge and the air valve by leaving the bike in the car in the hot sun with the windows closed! Luckily it was repaired under warranty. These are the 1998 SIDs.

-- Joe (, August 28, 2001.'re right. The main reason why I asked the question is that SID forks are a bummer to set up. I noticed that the negative chamber is soooo difficult to pump up to the right pressure and it always losses air when you remove the pump valve socket. I think this is so because 1. Rockshox is a bloody rip-off company that makes sub- standard forks, 2. They are made in Taiwan, 3. The positive pressure pushes the air in the negative chamber so that any air inside will quickly escape when you pull out the pump. or 4. I've got a fault fork.

-- Matt 0123828476 (, August 28, 2001.

I always fully deflate my SID's before a flight, and have never had a problem with damage. But the negative air chamber did start to become touchy to set up because of the inflation tool itself. When new it was fine, but after a while it no longer properly released the little check valve in the shock when fully inserted. I would be happily inflating the tool's tube and nothing else, and upon removal all pressure would be lost ... because none of it had made it into the shock reservoir. By carefully filing just a little bit of the threaded portion of the insertion fitting this has been taken care of. Now it inserts deep enough to open the shock valve properly.

You can tell it's right when threading in the tool, as on full insertion the gauge will pop to the existing pressure in the reservoir. Also when it's right and the o-ring on the tool is healthy and has a little bit of oil on it you can remove and replace the tool as many times as you like without losing any reservoir pressure. I routinely check the pressures in all three reservoirs before rides and races and they are bang on, nary a drop of air lost in months.

The other thing I find about repressurizing the SID's from scratch is that due to the interaction of the positive and negative reservoirs you will have to go around each of them at least twice to bring them up to the pressure you want.

-- Pat Brunsdon (, August 31, 2001.

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