Gaiters - vent holes??

Back in the dirty days we used to cut with a razorblade a tiny triangular flap valve for venting in the topmost ridge of the gaitor, and have this faced to the rear. Worked better in keeping moisture out than the holes.
However, due to condensation, be prepared to lift those gaitors on a regular basis to have a looksee/cleanup.
 
correct gators don't have gills so they can't breathe under water...
oops different gaiter we are talking about sorry.
 
Smartv11 said:
Bought a pair of fork gaiters, which don't have vent holes. I wonder should I make some holes, or is not really going to be an issue?

Paul
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You need 1 hole per gaiter. Seen plenty of gaiters that 'look' twisted, that's cause they act as a bellows. Easier fir air to expell than return. Heat red hot a piece of wire and burn a hole in the top flute and mount with hole to rear. Old speedway trick, Prior to leading link front ends.
 
mauricejota7604 said:
The gaiter rubbers have a couple of tiny vent holes about 2mm in diameter
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If you're talking about dynamic venting as the forks pump up and down, air is a viscous fluid and the volume inside the gaiter will change too rapidly for the tiny vent holes to do much venting at all. you'd need a bloody big hole for that - too big for any practicality I suspect. By that I mean if you cut big holes in them you're kind of defeating the purpose of the gaiters in the first place.  So what's the purpose of the wee holes?

Albert Einstein came up with his theories by doing what he called "thought experiments", just thinking about how things work and what must be happening. So I've been doing a thought experiment about a gaiter on a working fork leg:

The little bleed hole won't allow sufficient air through to vent the gaiter fully under the rapid compression of the fork leg as the front wheel hits a bump at speed. But the gaiter will expel air on compression easily enough because it will expand slightly with the internal air pressure and blow the air past the seal on the fork slider or at the top fitting. So there's minimal risk of it bursting due to internal air pressure. Thinking about this, it might be a bad idea to fit gaiters with jubilee clips (at both ends) to hold them in place. 

As the forks extend again, the pressure inside the gaiter will decrease, which will hermetically seal the lips of the gaiter against the fork slider and top fitting. So the air expelled on compression won't be sucked back in on extension. The sides of the bellows will collapse in a bit and may rub against the fork leg, but that's no big deal. The net result will be that the bellows will (on average) run with lower than atmospheric air pressure.  As soon as you stop the bike and get off, the elasticity of the deflated rubber gaiter bellows will suck air back in through the little bleed hole. So the gaiter will have returned to its normal shape before you've had time to notice anything different.
 
So now we need to bleed the additional air that builds inside the forks and also bleed for the same reason the gators. Maybe that's why my forks are harsh. He said with a big grin. BTW there is a big doco coming up on Foxtel about Albert, love his thought experiments about trains at the speed of light, with Geoffrey Rush playing him. Looks pretty good. What a brain that man had.
 
Ever wonder what that screw in the top and the little hole under Maz fork caps are for?, If you remove the screw, you'll find a spring and a ball bearing that are designed to do exactly that, to keep the internals at negative pressure. :P
 
And if you look at the set up on GTL ! all the answers are there , gaiter vents and  ball bearing valve in the top of the fork leg , 🙂
 
Dellortoman said:
If you're talking about dynamic venting as the forks pump up and down, air is a viscous fluid and the volume inside the gaiter will change too rapidly for the tiny vent holes to do much venting at all. you'd need a bloody big hole for that - too big for any practicality I suspect. By that I mean if you cut big holes in them you're kind of defeating the purpose of the gaiters in the first place.  So what's the purpose of the wee holes?

Albert Einstein came up with his theories by doing what he called "thought experiments", just thinking about how things work and what must be happening. So I've been doing a thought experiment about a gaiter on a working fork leg:

The little bleed hole won't allow sufficient air through to vent the gaiter fully under the rapid compression of the fork leg as the front wheel hits a bump at speed. But the gaiter will expel air on compression easily enough because it will expand slightly with the internal air pressure and blow the air past the seal on the fork slider or at the top fitting. So there's minimal risk of it bursting due to internal air pressure. Thinking about this, it might be a bad idea to fit gaiters with jubilee clips (at both ends) to hold them in place. 

As the forks extend again, the pressure inside the gaiter will decrease, which will hermetically seal the lips of the gaiter against the fork slider and top fitting. So the air expelled on compression won't be sucked back in on extension. The sides of the bellows will collapse in a bit and may rub against the fork leg, but that's no big deal. The net result will be that the bellows will (on average) run with lower than atmospheric air pressure.  As soon as you stop the bike and get off, the elasticity of the deflated rubber gaiter bellows will suck air back in through the little bleed hole. So the gaiter will have returned to its normal shape before you've had time to notice anything different.
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Cam,

That may well be correct, in theory. 

In practice, the 2mm vent holes work fine, with no deformation during deflection over bumps... :D

piet
 
sfcpiet said:
Cam,

That may well be correct, in theory. 

In practice, the 2mm vent holes work fine, with no deformation during deflection over bumps... :D

piet
Click to expand...

Cast your mind back to covensional forked PE dirt bikes, gators always look twisted after working hard.
They had a shitload of air to deal with breathing in and out.
Frankly, I never considered gators as dust brotectors, more as hard chrome protectors.
 
Yes Chris, do remember that. 

But I was referring to road bikes with gaiters, a lot less movement and total travel.

piet
 
Well, my ramblings are all just idle speculation. Only gaiters I've ever used are the ones you strap on over your boots when bushwalking to stop your boots getting full of mud and your socks getting torn to shreds on the scrub. They also make it a bit harder for the snakes to sink their fangs into your ankles.
 
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