Sub-tank Idea for Jeremey Wilkey

[ShawnMc]

Using the bimba style valves that free flow one direction and meter in the other I had a thought.

Im using a pair of valves on the fork to meter out. What would you think about using a third to be able to meter back out of the tank and giving an adjustment to that flow direction too?

I converged the lines prior to entering the tank, so I only have one port into the tank, and a bleeder in the other. So Id only need one valve and could use a larger ported valve (1/4" instead of the normal 1/8') to handle the required flow.

My only real concern is, the "free-flow" aspect isnt 100% free. So an adjustment would have to be made to the out flow valves, but that seems easy enough.

Ive got no desire to sell this, I just like messing with it. :thumb:

Mr Wilkey, Id' enjoy your thoughts regarding this... :worship:

 

[ShawnMc]

Bump

 

[ShawnMc]

bump

 

[ShawnMc]

Bump no.3

Is this getting ignored? :ugg:

 

[NO HAND]

Shawn, not many people understand the principle of subtanks so maybe it is very technical for most. I know Jeremy is very busy. The easiest way to contact him is calling at Mx-Tech. He knows alot about subtanks and has been testing some enzo prototypes lately. Because of that it is understandable that some of the info he knows may be secret and perhaps it would be hard to comment on this post without spilling the beans. It sure sounds like a good idea to have independent adjustments for the back flow. I guess the key element is testing... and testing.

 

[marcusgunby]

Shawn ddi you want to discuss this point in general or just with jer? as the wording of the thread made me not respond even though i like to chat about all suspension stuff.

 

[ShawnMc]

Shawn ddi you want to discuss this point in general or just with jer? as the wording of the thread made me not respond even though i like to chat about all suspension stuff.

Jer would be great, but I'll talk to anyone about it really. Jeremy is just adamant about metering in and out of the subtank. I just wondered if he had an opinion on adjustablitly on metering out of the subtank.

My thought is, the rebounding pressures in the tank are far less than any incoming pressures. So when your using a needle type valve (meters both directions) your back flow would be far less because of the (or lack of)pressure in the tank itself.
It seems to me this would allow the fork to "pack" over consecutive bumps.
Jeremy's assertion that the fork will "completely reload" totally if the front wheel leaves the ground may be right, but isnt that what the valve is for anyway. And I mean the valve setting that allows the the fork to bleed off pressure.

Anyway, Ive been riding the setup I built using the check vavles and I haven't noticed any of the issues that Jeremy swears I'll have. I am also planning on experimenting with a single valve metering both forks with the check valve and needle type.

I can tell ya this: My fork is way way better with my system in place than it was prior. Before I could tune the oil hieght for bumps, but bottoming was a huge issue, and vice versa. Now Ive got the best of both worlds, which is taking some getting used to, as I'm still flinching and bracing for harshness that never really materailizes.

So Marcus, what are your thoughts on it? Ive watched your posts for sometime now and I know your a smart guy and I respect your opinion.
Whaddya think? :)

 

[russ17]

Think about this, as far as the pressures being different, What about suction on the reb. Here is a experment.
Example) with the fork tubes completly colapse( naturally with the fork caps off) put the palm of your hand over the tube and pull up. You will feel some major suction. I would think this would have a great effect in drawing the air that is displaced from the subtanks back into the forks. So would this be equal or not. Do we have two forces acting on the return side. 1-being the pressure that is built up in the subtanks and 2) the suction that is acurring on the reb.
Maybe something to think about.

Russ

 

[ShawnMc]

Valid point russ17, assuming you could push all the air out. But since the fork retains some pressure a vaccum never develops. So there is just a pressure differential, which technically can be called a vaccum I guess.

But that does kind of show me what Jeremy might have been asserting about the fork "sucking" and being harsh on consecutive bumps. Ive got some more experimenting to do

 

[russ17]

Could we say that the fork creates a negative pressure.( In the case of the subtanks) That being less air is being supplied to a space then is exhausted from the space.
If so air will move or flow from high pressure areas to low pressure area.

 

[ShawnMc]

Agreed.

Im going to test three different configurations the next time I test.

I'll post what I find out... :thumb:

 

[DEANSFASTWAY]

Shawn I undersytand what youre stating and it does have some merit. You should always consider that youll want to have some pressure in the fork as it helps the cartridge fill and if you run it at neg pressure you might suck dirt and grit in through the seals and wipers, ive seen that happen on woodsies bikes with push bleeders.Weve also tried running a bit of pos pressure (small amount)in the Enzo Tanks on big heavier bikes to help them react but the point was rather moot and no real difference was felt as tested anyway. Keep going.

 

[ShawnMc]

Dean, your right and with the check valve system a negative pressure situtation cant happen. Jeremy's point of the fork reloading and becoming harsh seems to also discount the outflow valve setting.

Like I said, Im going to continue to test both styles of valving.

 

[DEANSFASTWAY]

Kool