Funny- Adding fork air pressure

[ArtByScars]

So I just ended up laughing...
yesterday I put new fork seals in and put everything back together- The manual says "8.5 psi" for the forks...

Well that's nearly impossible to do with a compressor, so I got out ye' ole bike pump...
How in the world do you put that small amount of pressure in and not have it escape when you take the valve off????
Every time I take it off it goes "TSSSST!" real quick and that is all the air I just put in! LOL

and no- I'm not putting progressive springs in to avoid this- I want to know how to do it. I'm deleting this post if we start talking about progressive yadda yadda springs, I don't have them and am not getting them, so that kinda speak is useless here.
Talking stock front forks, how do we keep the air from escaping when we take the valve off after putting the "8.5lbs" in..?

[André]

I have used a manual air pump with an integrated gauge, pumped until 10 psi (approx.) and reajust with a small hand gauge and "voila".

Sometimes simple solutions are too obvious.

[salty_monk]

Or buy yourself a low pressure suspension pump. Mountain bike shops sell them.

You can also cut some length off the stock spring & replace with a solid spacer (cut the tightly wound end) if you want. That will serve a similar purpose as replacing with those springs we're not allowed to mention...

[Redman]

http://www.amazon.com/Progressive-Suspension-Hand-Pump/dp/B002OKK4QO

This is like the one I have, except the one I have has a hose about 5 inches long.

Maybe the ones avaialble at bycycle shops might cost less.

.

[Don-lo]

Turn the air compressor off, bleed the air down to 9 psi, fill forks. Be consistent with your "TSSST", and the air pressure will be consistent between the 2 forks. Being consistent is most important since that prevents uneven forces in the forks.

A small dial air gauge usually gives me a 1 psi drop per "TSSST". Practice filling and rechecking the pressure several times to gain confidence with the procedure.

A schrader valve connected to a precision air gauge with bleed-off would be the most accurate system.

[gearhead13]

I pump mine up to about 15 and I have a digital guage that reads in 1/2psi increments, everytime i check the pressure with the guage I lose 2 psi or so. The guage is from Canadian Tire and cost about $10. I use a small bicycle pump to put air in.

[Charlie G]

This is what I use. Took me awhile ( like 10 months!) to find the right set up. I couldn't find a pump which had a fine enought gauge, so I adapted one. Most pumps now for bicycle suspension are much higher that we need.( I looked Dan and couldn't find one) I went to 6 shops and looked a little on line. Looked at all there catalouges and in the end just changed the gauge.



This is a BUZZY's Pollonator pump. The lowest gauge they make is 0-200psi. I bought a 0-30 gauge from hardware store and a brass reducer to make it work. The female threads on the pump are really tight and for a while I thought they were metric, which caused me to give up on it for a long time. You need a fine increment gauge. I use 12psi. I think the manual states 7psi and the sticker on the forks 36psi max.(82 650g).



The pencil is pointing to a relief valve button. Press the button to adjust ( release) pressure to exactly what you want. Unscrew the pump and it remains at what you set it at, if (?) your seals and O-rings are good.

I tried using a dedicated regulator,set to the required pressure, to fill the forks. Every time I took the filler hose off it would bleed out to less. The hand pump works extremely good. I wish it was about half a long. It's slill light enough to take with you on a tour, but I wish I could put it under the seat. I loose about one lb. pressure in two weeks, so I don't need to have it with me all the time. Good luck. The small gauge is the one which came with it and I took off. http://www.amazon.com/Buzzys-Pollina.../dp/B000GJWK1W

I paid $5 less at a shop and another $17.00 for gauge and adapter.

Charlie G.

[salty_monk]

http://www.jensonusa.com/store/sub/292-Pumps+And+Co2+Inflation.aspx?s=1559

Take your pic.... The Marzzochi has a 30psi dial as does the planet bike which I think is the same shock as the last one listed. Pretty sure the Manitou SPV has a dual gauge on it too.

Jenson are a good store, I've used them a few times.

Most mountain bike suspension runs high pressure but some run low and some have a low pressure top out spring with a high pressure main spring hence the combination pumps.

Another way to stiffen the fork is to raise the oil height in the leg. Thus decreases the air gap above it and so the remaining air is compressed more by the fork stroke.

Dan

[ArtByScars]

thanks for all the replies!
My friend is a mtn bike tech down at one of the shops, I talked to him and he said they have shock pumps that should work fine.
I'm going to give that a whirl later today.
Thanks for the idea(s)

[bwringer]

If you're too cheap to buy new fork springs, follow the advice above and cut four or so inches off your stock springs to increase the spring rate to a respectable degree. Then reinstall with longer preload spacers made from PVC pipe (you can probably steal some pipe from a construction site if you're that broke).

Change the fork oil while you're in there -- perhaps you can get your Mom to save you some old Wesson oil or something.

Air pressure is an unreliable, dangerous, pi$$-poor substitute for fork springs of the proper spring rate and the right amount of preload to get sag in the right ballpark. You don't need a better air pump -- you need to fix the actual problem.

[Clone]

Turn the air compressor off, bleed the air down to 9 psi, fill forks. Be consistent with your "TSSST", and the air pressure will be consistent between the 2 forks. Being consistent is most important since that prevents uneven forces in the forks.

A small dial air gauge usually gives me a 1 psi drop per "TSSST". Practice filling and rechecking the pressure several times to gain confidence with the procedure.

A schrader valve connected to a precision air gauge with bleed-off would be the most accurate system.

+1 for bleeding down the compressor, but I also dial it down on the pressure guage to 10lbs too