Front fork air pressure

stuartadair · Crazy Courier Joined: 15 Oct 2009 Karma :

This FZ400 I've just bought has got air valves on the top of each fork. It looks like you connect an air line to add pressure to the forks.

I've never seen that before - What sort of pressure should I add ?

Stu

DMCpro · Traffic Copper Joined: 16 Jul 2012 Karma :

Not exactly, they are filled with gas can't remember what the gas I'd called though! Someone will
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stuartadair · Crazy Courier Joined: 15 Oct 2009 Karma :

Oh I'm not liking the sound of that. The fork seals are gone so I've got to strip them down and replace. Hope its not going to be complicated with having to get them filled with a gas Sad

jjdugen · World Chat Champion Joined: 03 Jun 2011 Karma :

Another 80's fad along with 16'' front wheels and hydraulic anti dive.
The pressure in them was circa 5 psi, you could only use a cyclepump on them, an air line would overpressure and blow the seals.
Its just air, so no special gas needed, in fact, ignore them entirely. You might put a few cc's more fork oil in, this has much the same effect.
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DMCpro · Traffic Copper Joined: 16 Jul 2012 Karma :

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Varies depending on the model, but generally VERY little air pressure or none.

DMC, there were the Fournales air shocks but not sure about forks

All the best

Keith
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stuartadair · Crazy Courier Joined: 15 Oct 2009 Karma :

Thanks for the replies

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

Not much air - last ones I had were 7psi. Don't try using a40 air line, use a foot pump.
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sickpup · Old Timer Joined: 21 Apr 2004 Karma :

caferacer · Nova Slayer Joined: 11 Aug 2012 Karma :

All cool bikes have air valves on the top of the forks - chicks dig them.

My 80s Honda CB125RS has them lol

Fill it with the standard oil cc then the idea is you can easily adjust for ride comfort - low pressure for light loads, soft ride and smooth roads and high pressure for heavy loads and rough roads.

Between 0 and 7psi is about right.

Vincent · Banned Joined: 16 Oct 2006 Karma :

Last one I had was 2psi IRRC. Whatever you put in doesn't seem to stay in there very long though.
I've known a few people pump them right up and blow the seals Rolling Eyes

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stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

I always used to set them to zero with the forks totally unloaded (front wheel off the ground, stick key in valve).

This probably equates to somewhere in single figures of psi with them sagged.

It doesn't seem to make an iota of difference to the behaviour of the suspension anyway.
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