Rock Shox Mag 21 style air needle valve

[dencal]

Ok , you mean to made a point with 3 faces ? anyway i will try with syringe needle, and still use it for inflating (after rounding the sharp tip),less the hole is less air will be loose.I will adapt with bi -component adhesive , the syringe needle to the pump adapter (without using the football needle).

Let'see

 

[FSXStumpy]

Yeah, a 3 face point, a long, 3 sided pyramid point. Took 5 minutes with a whetstone and an old spoke. Resulting air valve doesn't leak at all, and I inflate it with the standard Rock Shox needle (or more accurately, a ball needle modified by me to remove the side port and round the tip).

There's no need to re-invent the wheel... But what you propose will probably work just fine. More work than you need to put into it is all.

J

 

[dencal]

Yes ,you're right !
Thanks i let you know how it's working in the very next days

 

[FluffyChicken]

Re:

There are two style MAG10 vakves, the bugger awful 93 ones the sit in a plastic cartridge like the 92 MAG30s and the nice 94 ones with the best top caps and easier of all the MAGs and uses the normal air plug.

Don't sharpen the pump valve, you'll just tear it every time you use it. Just use a thick pointy pin or as above make a point on a spoke etc.

 

[dencal]

Re:

Hi Fluffy, I was reading all your post regarding this matter, so mine is the 94 mag 10, the rubber capsule is inside allumin cylinder.
You know maybe how many centimeters it will be cut? The rubber extracted is 8mm high, but maybe because squeeze for long time? I read somebody cut the Silicon cylinder to 10mm and not as the original (8mm)

 

[FluffyChicken]

I can check length but when you look in the valve tube there is a recessed lip, you need to be as long as that.
Any longer and you push down on the adjuster rod and can bend the.
Any shorter and they can move around which is less of a problem.

It might be a squeeze getting that cord in
BUT that looks like Nitrile O-Ring cord and not a silicone. If so, any I have tried have been far to hard to get the needle through once fitted.

 

[dencal]

Yes, because the nitrile capsule/valve have a conic hole on the adjuster rod,so,the pin don't need to go trough 8mm of nitrile material, but only, i will say, 4mm.
Silicone is very soft,easy to pierce, but easy to damage, BUT at the end , when i've already prepared 10 "self made" spare valves,the replacement operation is so easy that doesn't justify the research of the right material. I'm will be more tha happy if i will replace that 1 or 2 times/season .

If the silicone "self made" valve will fail, i'm ready to buy Nitrile Cord and test it .

This evening i will be on my Garage for the assembly ! Let'see.

 

[dencal]

Re:

Hi at all!
My mag 10 is OK now, silicone self made valves are fine, but too soft i think.
But I suspect that something is wrong on this fork, because the rebound is not soft(too fast) , like the oil doesn't make the job, but I can hear the oil noise (squeeek squeeek ) . Oil quantity is 5 centimeters (5W), and air pressure is 45 psi
Maybe someone can help me?

 

[FSXStumpy]

The silicone valves will stiffen some in time. They do start out fairly soft, depending on just which RTV sealant you used.

Rebound tends to be relatively quick on Mag style forks, quicker than on a modern fork. You should hear the noise of oil flowing thru the ports on rebound.

You can adjust rebound speed by changing the oil weight. 7.5W (or 50/50 mix of same brand 5W and 10W) might do just the trick to slow your rebound. Beware, however, that if the rebound is too slow, the fork will "pack down" over rapid stutter bumps. Stock oil recommendation for the Mag 10 was 8wt ATF (automatic transmission fluid). 5wt would have a more rapid rebound. 10wt might feel slow, especially for lighter riders, running lower pressures.

What do you weigh? 45psi would be appropriate for someone in the 200#, typically. When I weighed 165#, I used 41psi. Today, at 225, it's 52psi.

Raising the oil height would allow you to run less pressure and yet still resist bottoming. Try it closer to 45mm from the top of the leg, fully compressed.

Here's a tuning guide, from this site:

http://www.retrobike.co.uk/gallery2/v/M ... d.jpg.html

J

 

[dencal]

Re:

Thanks a lot!
I was following the rockshox mag21/10 pdf, for pressure and oil density, I'm 72kg.
I was using normal domestic silicon tube, the one used on the bathrooms.
I know is not the right one, but just because I want to buy the nitrile cord on eBay, when the actual valves will fails.
What mean RTV?