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Discussion Starter · #1 ·
I was thinking of trying a little more compression on the Pike (454 Dual Air) to see
how that would affect the feel on kind of steep, droppy kind of stuff.
I think it might dive a tad too much right now as I feel I'm getting bucked a little bit in the back. My setup is I've got the DHX in the rear at 200 psi in the main chamber,
and I think I've also got that in the Pike's positive chamber although that might be off by 10 psi, it might only be 190.
There's supposed to be a way to adjust compression on this fork via a knob somewhere, am I wrong about this ?
(The Sram website was not helpful by the way) Thanks
 

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Discussion Starter · #3 ·
It is a poplock model. There's a 'Gate' or Floodgate' adjustment knob on the right.
Don't really know what that is for. I tried adjusting that on my ride yesterday, not really
sure what it did.
So is there no way to low speed compresion asjust on this fork, then ?
 

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id you have a poplock model, you can only adjust the compression level if you use the poplock adjust (the one with a compression dial), with the regular poplock you can only have it locked/unlocked......however the floodgate regulates how "hard" the lockout is, in other words the threshold to overcome the lockout, so if you set the floodgate low, the lockout will open when the threshold is overcome.
 

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Discussion Starter · #5 ·
crisillo said:
id you have a poplock model, you can only adjust the compression level if you use the poplock adjust (the one with a compression dial), with the regular poplock you can only have it locked/unlocked......however the floodgate regulates how "hard" the lockout is, in other words the threshold to overcome the lockout, so if you set the floodgate low, the lockout will open when the threshold is overcome.
Thanks for the info. On my last ride I tried setting the floodgate about halfway
but with the compression dial all the way open, and with the red rebound knob
on the bottom of the right leg all the way to the right, which I think made the rebound all the way fast. Felt a bit harsher than what I was
used to, but I'm trying to find an optimum setting where I can do some 3 footish
type drops without the fork diving so much that I feel like I might go OTB.
(Still haven't got all my confidence back after my broken wrist accident back in Dec.)
So I'm trying to experiment to see what feels best. Is the compression dial
then just an on or off thing, meaning you can't set it halfway ?
If I had the compression dial in the 'lockout' position with the 'gate' adjustment set
a couple clicks from '-', would that be a good place to start to get the feeling
I'm looking for ? Thanks.
 

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le_buzz said:
Thanks for the info. On my last ride I tried setting the floodgate about halfway
but with the compression dial all the way open, and with the red rebound knob
on the bottom of the right leg all the way to the right, which I think made the rebound all the way fast. Felt a bit harsher than what I was
used to, but I'm trying to find an optimum setting where I can do some 3 footish
type drops without the fork diving so much that I feel like I might go OTB.
(Still haven't got all my confidence back after my broken wrist accident back in Dec.)
So I'm trying to experiment to see what feels best. Is the compression dial
then just an on or off thing, meaning you can't set it halfway ?
If I had the compression dial in the 'lockout' position with the 'gate' adjustment set
a couple clicks from '-', would that be a good place to start to get the feeling
I'm looking for ? Thanks.
I'd get the PopLoc adjust lever... I can see what you mean and you're not going to get rid of it but adding more lo speed comp or playing with the Dual Air.
 

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You can get a lot of what you need by lowering the negative pressure and keeping the poploc. You haven't told us what negative/positive pressures you are running.

le_buzz said:
Thanks for the info. On my last ride I tried setting the floodgate about halfway
but with the compression dial all the way open, and with the red rebound knob
on the bottom of the right leg all the way to the right, which I think made the rebound all the way fast.
Reading about some of the things you've tried, I think you need to go back to basics on your suspension setup.

With the Pike (poploc) you have:
- two air chambers to tune the spring rate
- a rebound adjust
- a lockout control (poploc)
- a blow-off threshold for the compression (floodgate)

It sounds like you haven't set up the air pressures properly. All other changes are sticking plaster until you get the air pressures right. I'd be very surprised if you've got 200 psi in your positive air chamber. You need to be accurate with air pressures.

The dual air concept allows you lots of fine tuning of the fork feel. The way most people seem to be approaching dual air setups these days is to set a positive pressure that means you get to use most of the travel with the bigger hits - this is usually less than the Rockshox recommendation. The negative pressure usually works out best if kept a little lower than the positive pressure, but this is worth experimenting with *a lot*. If you keep the negative too close to the positive, the top part of the stroke becomes too soft and the travel falls through the midstroke before the rising rate of the positive spring suddenly comes into play. It sounds like you have this situation. It is very disconcerting.

As you lower the negative pressure, the spring behaviour becomes more 'joined up'. I would recommend lowering the negative pressure just enough to eliminate the 'falling through the midstroke' feeling. This probably means no more than 10 psi lower than the positive, although some riders find they need more difference. You need to start making your changes in 5psi increments and you need to know what pressures you are running. Currently you have told us you don't know whether you are running 190 or 200 in the positive chamber, both of which sound far too high to be believable.

The rebound adjust is responsible for delivering most of the grip out of the fork. Winding it all the way to the extreme ends of its travel results in a fork that will not be working properly. i.e. no grip... pogo stick... another broken wrist accident beckoning. If you have wound it all the way slow, the fork will be packing down and will again have less grip and the geometry will steepen leading to the chance of the fork tucking under. The ride will be harsh in both cases. To set up rebound it is probably easiest to start with it too fast and dial it in until the trail chatter starts to smooth out. You shouldn't be planning any aggressive moves until you have got it close. From the point where things smooth out, you have a turn or two for fine adjustment before the fork will definitely be too slow.

If you change the spring rate, the rebound will need more fine adjustment. If you lower positive air pressure, the rebound should be set faster. If you lower the negative air pressure, the rebound can afford to be a bit slower - this is a nice effect; if you tune the rebound for small bumps, the fork will take big hits in a more controlled way and the rebound won't throw you off the bike.

I think that's about it. You would do well to get the basic setup right before getting a poploc adjust. If you need more slow speed compression control after doing this setup, then it is time for a poploc adjust.
 

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That was 200psi in the rear shock, DHX air, correct?

If you are getting bucked, yes the fork might be diving but the shock can be a factor too.
Try slowing the rear rebound 2-3 clicks and see if it bucks less.

Also, having the fork rebound too slow can make it dive (over repeated bumps anyway).
 

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Discussion Starter · #9 ·
petercarm said:
You can get a lot of what you need by lowering the negative pressure and keeping the poploc. You haven't told us what negative/positive pressures you are running.

Reading about some of the things you've tried, I think you need to go back to basics on your suspension setup.

With the Pike (poploc) you have:
- two air chambers to tune the spring rate
- a rebound adjust
- a lockout control (poploc)
- a blow-off threshold for the compression (floodgate)

It sounds like you haven't set up the air pressures properly. All other changes are sticking plaster until you get the air pressures right. I'd be very surprised if you've got 200 psi in your positive air chamber. You need to be accurate with air pressures.

The dual air concept allows you lots of fine tuning of the fork feel. The way most people seem to be approaching dual air setups these days is to set a positive pressure that means you get to use most of the travel with the bigger hits - this is usually less than the Rockshox recommendation. The negative pressure usually works out best if kept a little lower than the positive pressure, but this is worth experimenting with *a lot*. If you keep the negative too close to the positive, the top part of the stroke becomes too soft and the travel falls through the midstroke before the rising rate of the positive spring suddenly comes into play. It sounds like you have this situation. It is very disconcerting.

As you lower the negative pressure, the spring behaviour becomes more 'joined up'. I would recommend lowering the negative pressure just enough to eliminate the 'falling through the midstroke' feeling. This probably means no more than 10 psi lower than the positive, although some riders find they need more difference. You need to start making your changes in 5psi increments and you need to know what pressures you are running. Currently you have told us you don't know whether you are running 190 or 200 in the positive chamber, both of which sound far too high to be believable.

The rebound adjust is responsible for delivering most of the grip out of the fork. Winding it all the way to the extreme ends of its travel results in a fork that will not be working properly. i.e. no grip... pogo stick... another broken wrist accident beckoning. If you have wound it all the way slow, the fork will be packing down and will again have less grip and the geometry will steepen leading to the chance of the fork tucking under. The ride will be harsh in both cases. To set up rebound it is probably easiest to start with it too fast and dial it in until the trail chatter starts to smooth out. You shouldn't be planning any aggressive moves until you have got it close. From the point where things smooth out, you have a turn or two for fine adjustment before the fork will definitely be too slow.

If you change the spring rate, the rebound will need more fine adjustment. If you lower positive air pressure, the rebound should be set faster. If you lower the negative air pressure, the rebound can afford to be a bit slower - this is a nice effect; if you tune the rebound for small bumps, the fork will take big hits in a more controlled way and the rebound won't throw you off the bike.

I think that's about it. You would do well to get the basic setup right before getting a poploc adjust. If you need more slow speed compression control after doing this setup, then it is time for a poploc adjust.
Wow, thanks for this helpful info. I need to take some measurements to see
what the actual neg/pos numbers are, but I remember after getting back on my bike a few months after my accident bumping the pos air chamber up to 190
from about 175. This was the first time I've messed with it since setting it up
when I got the bike. I'm pretty sure the bike was originally set up in the neighborhood of 175/150 for pos/neg values. I'm planning on doing a short ride this aft. I will check those before hand.
Is 150 in the negative what more people my weight range (200) run, or is that a bit high ?

Warp, can you tell me more about the modification you talking about ?
How do you go about doing that ? Thanks
 

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le_buzz said:
Wow, thanks for this helpful info. I need to take some measurements to see
what the actual neg/pos numbers are, but I remember after getting back on my bike a few months after my accident bumping the pos air chamber up to 190
from about 175. This was the first time I've messed with it since setting it up
when I got the bike. I'm pretty sure the bike was originally set up in the neighborhood of 175/150 for pos/neg values. I'm planning on doing a short ride this aft. I will check those before hand.
Is 150 in the negative what more people my weight range (200) run, or is that a bit high ?
The negative should be set relative to the positive. Rockshox recommendations for the DualAir only go up to 150psi (+ve) for riders over 220lbs and Rockshox recommended pressures are usually too high. If the fork is the Air U-turn, the pressures are slightly higher up to 175psi for the same 220lb rider. It sounds like you are above the recommended pressures for a 200lb rider.

When you are setting pressures, you must start by dropping the negative pressure so there is no chance that the fork will not be fully extended. Set the positive and having set the positive, start pumping up the negative. Try to keep the negative from ever going higher than the positive because it tends to suck the fork down in its travel and also makes accurate pressure readings difficult.

To give you an idea, on a Dual Air Revelation I ride at 95+/85- and I weigh 200lbs.
 
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