Flow-Rider
Burner
Internal floating piston, it's a piston that separates the oil from air or gas.
Metal Working! Fitting, Machining, Welding, Sheet and General Metal Fab
- Thread starter Urban DH
- Start date
link1896
Mr Greenfield
Now now, no judgement around here. I’m sure life still has meaning and purpose. Or so they tell me.
The IFP, internal floating piston, is the most popular method to seperate the gas from the oil in a damper. The oil needs to be pressurised so it doesn’t cavitation during fast strokes, sit back down komdotkom.
Say you’re landing the bike from a big jump, the shock is slammed hard to full stroke. The shaft speed is very high. The shock’s damper provides some energy absorption via damping, aka resisting the pistons travel through the oil. What we call compression damping. The oil’s viscosity works in conjunction with the compression circuit to provide this resistance. When oil cavitates, it changes state from liquid to a gas. Gas has a fraction of the viscosity of oil.
Now on the rebound stroke, the spring or air can is providing maximum rebound force. The rebound damping circuits job is to slow this down, so we don’t have a pogo stick. If the gas pressure on the ifp wasn’t there, the oil wouldn’t be pressurised, and again we’d have massive, temporary viscosity loss due to cavitation, and a pogo stick.
Here is a cutaway of an old RP23 shock, with the IFP circled.
The IFP fjohn860 is talking about wasn’t in the damper side of a shock, but for a dual air chamber setup in forks. Instead of volume reducers, you can run a slave air chamber. The IFP separates the high pressure and low pressure air chambers. The main chamber, in the fork stanchion can be set at a lower pressure, for better coil like feel. The air chamber is set higher, becoming an influence on the air spring force, as the fork goes deeper into its travel.
Check here for a lovey little animation.
runt — diaz suspension design
Insert for mountain bike suspension air forks that provides a coil like feel while maintaining a lower weight, infinite adjust-ability, and lower price.
diazsuspensiondesign.com
Ultra Lord
Hurts. Requires Money. And is nerdy.
Brilliant explanation.Now now, no judgement around here. I’m sure life still has meaning and purpose. Or so they tell me.
The IFP, internal floating piston, is the most popular method to seperate the gas from the oil in a damper. The oil needs to be pressurised so it doesn’t cavitation during fast strokes, sit back down komdotkom.
Say you’re landing the bike from a big jump, the shock is slammed hard to full stroke. The shaft speed is very high. The shock’s damper provides some energy absorption via damping, aka resisting the pistons travel through the oil. What we call compression damping. The oil’s viscosity works in conjunction with the compression circuit to provide this resistance. When oil cavitates, it changes state from liquid to a gas. Gas has a fraction of the viscosity of oil.
Now on the rebound stroke, the spring or air can is providing maximum rebound force. The rebound damping circuits job is to slow this down, so we don’t have a pogo stick. If the gas pressure on the ifp wasn’t there, the oil wouldn’t be pressurised, and again we’d have massive, temporary viscosity loss due to cavitation, and a pogo stick.
Here is a cutaway of an old RP23 shock, with the IFP circled.
The IFP fjohn860 is talking about wasn’t in the damper side of a shock, but for a dual air chamber setup in forks. Instead of volume reducers, you can run a slave air chamber. The IFP separates the high pressure and low pressure air chambers. The main chamber, in the fork stanchion can be set at a lower pressure, for better coil like feel. The air chamber is set higher, becoming an influence on the air spring force, as the fork goes deeper into its travel.
Check here for a lovey little animation.
runt — diaz suspension design
Insert for mountain bike suspension air forks that provides a coil like feel while maintaining a lower weight, infinite adjust-ability, and lower price.
You should start a weekly “learning things with link” thread.
Jpez
Down on the left!
If you’ve got the patience or intelligence of which I lack both Steve from Vorsprung does brilliant YouTube vids on all sorts of nerdy suspension topics. I try but just glaze over by the halfway point or I learn something new but because my brain is only so big when something new goes in something old goes out.
Definitely worth a look though.
Ultra Lord
Hurts. Requires Money. And is nerdy.
Yeah and it translates well to moto, I forward vorsprung vids to mates all the time rather than try and explain compression/rebound etc.
Mattyp
Cows go boing
beeb
Dr. Beebenson, PhD HA, ST, Offset (hons)
Bloody bible bashers!There's also the bible... But who reads books these days .
Haakon
has an accommodating arse
Not my own work, but had a duct piece made up. Not entirely to spec sadly and I’m going to have to rethink my attachment strategy somewhat but they refused to remake it the way I asked which was … disappointing…
I gave them the internal dimensions and asked for insulation which I assumed would go on the outside. Leaving me the full 40mm on the turnout at the end to attach to the timber frame it’s going into. But they put the insulation on the inside, robbing me of 25 of the 40mm for the turnout. Not ideal…
oh well, I’ll make it work with only fixings on the sides… Also, who knows if rockwool insulation is a good idea for inside a duct…? Feels like a dodgy idea, spreading fibreglass dust through the system!
edit - insulation seems legit. Odd. The perforations are a neat idea though making it act like a muffler. Mildly annoying they didn’t want to own their error, but I’ll live. Was only $360 which felt reasonable given the work that appears to gone into it.
I gave them the internal dimensions and asked for insulation which I assumed would go on the outside. Leaving me the full 40mm on the turnout at the end to attach to the timber frame it’s going into. But they put the insulation on the inside, robbing me of 25 of the 40mm for the turnout. Not ideal…
oh well, I’ll make it work with only fixings on the sides… Also, who knows if rockwool insulation is a good idea for inside a duct…? Feels like a dodgy idea, spreading fibreglass dust through the system!
edit - insulation seems legit. Odd. The perforations are a neat idea though making it act like a muffler. Mildly annoying they didn’t want to own their error, but I’ll live. Was only $360 which felt reasonable given the work that appears to gone into it.
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fjohn860
Alice in diaperland
LSNED
Haakon
has an accommodating arse
Yes indeed. Given all the PPE recommendations when dealing with it for wall insulation batts, I’d have assumed it was a no no for an area where it’s going to blowing air over it and into living spaces!
Flow-Rider
Burner
It should have filtering on the air ducts, but I can't imagine the condensation being a good thing for it either.
hellmansam
Likes Bikes and Dirt
No pics to show yet - my next step in hobby machining is to install a DRO on my milling machine. Have the linear glass scales and tablet for the screen, a TouchDRO box is on the way, due in the next couple of weeks.
Haakon
has an accommodating arse
Filter is to be on the main inlet - before this section…
Ultra Lord
Hurts. Requires Money. And is nerdy.
If a youtube video is too much for them I have little hope a textbook will help. Some people just hit the send button regardless of whats happening under them haha.There's also the bible... But who reads books these days .
Mattyp
Cows go boing
I guess this fits here...
Have had some spare timber and offcuts of RHS laying around for probably over a year after I got Jpez to make me up a timber bench top for a desk.
Been staring at them for a while meaning to do something with them, turns out I had a few spare hours yesterday and today so drew something up, and went to work. Used the offcuts from the 2 middle shelves to make a 4th one, it's a little short and had I thought about it harder would have taken an extra 10mm off the other 2 to make it bigger but it'll do.
Have had some spare timber and offcuts of RHS laying around for probably over a year after I got Jpez to make me up a timber bench top for a desk.
Been staring at them for a while meaning to do something with them, turns out I had a few spare hours yesterday and today so drew something up, and went to work. Used the offcuts from the 2 middle shelves to make a 4th one, it's a little short and had I thought about it harder would have taken an extra 10mm off the other 2 to make it bigger but it'll do.
I know a lot of you guys are used to working off CAD templates but my experience this time is that it is way too inaccurate and I mean the holes aren't even round, no dimensions and the lines are all wonky like a manky hobo chewed them and don't ask about squareness.
Anyway I went old school and redrew it. Need to throw some dimensions on, wait for a sunny day so I don't have to swim to the shed and get stuck in.
Anyway I went old school and redrew it. Need to throw some dimensions on, wait for a sunny day so I don't have to swim to the shed and get stuck in.
SummitFever
Eats Squid
Needed to make some thin spacers to fix bearing clearance on a hub I got from a burner a couple of years back. One is 0.8mm and the other 0.3mm.
Although this is a round part its difficult to make on a lathe. CNC machined out of 6061 plate.
Although this is a round part its difficult to make on a lathe. CNC machined out of 6061 plate.