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Discussion Starter · #1 ·
I'm about to dump $2800 on a Reign 08 and researched the components. I can't find anything positive about the Fox DHX AIR 4.0.

Is this shock THAT bad, or are the guys who only had bad experience with them posting their comments?
 

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noMAD man
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My DHX-Air 5.0 was a poor match to my Nomad, but it was quite decent for my Bullit. I notice my Nomad uses a higher spring rate when I use a coil shock than my Bullit does. The Reign is a linkage bike more comparitive to the Nomad than the Bullit simple single pivot. IMO the Reign will probably suffer from the DHXA soft mid-stroke as badly as the Nomad. The 4.0 version doesn't have the volume adjuster on the boost valve if I'm recalling correctly, and while this isn't as important as at least having the ability to change the boost chamber pressure, it will affect the ability to affect the progressiveness of the boost chamber. Unless you're a very light rider, I suspect the DHX Air will not be ideal for the Reign.
 

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Working on my Drops
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DHX air is not bad. It is just better suited for some bikes vs. others.
 

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what...?
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It is a good shock. just takes some tine to understand and set it up right.Most folks just want a shock they can pump up, set the rebound and ride. Not so with the DHX. Because the settings are so decoupled from the main chamber - which is only used to set sag - you can get set up without too much complication. If you are heavy- like over 200 - use the RP air can. makes a world of difference.
I tried the coil and the RP23....I'm staying with the DHXa.
 

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Discussion Starter · #5 ·
I'm not light or a fat ass..I'm a solid 190 pounds with 10% body fat. Now I'm in a real pickle. I want that Reign 0, but not if I'm going to have to replce the rear shock soon with the can.
 

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Slow Patrol
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jmtbkr said:
If you are heavy- like over 200 - use the RP air can. makes a world of difference.
I'll second this. I weigh 208 lbs and the small air can on the DHX-A makes the shock much nicer on my Kona Coilair (2.7 leverage).
 

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daugela said:
I'm not light or a fat ass..I'm a solid 190 pounds with 10% body fat. Now I'm in a real pickle. I want that Reign 0, but not if I'm going to have to replce the rear shock soon with the can.
Reign is a 3:1 leverage ratio bike just like my older QuasiMoto. Just put a DHXA on it (I weigh 230) and have been switching back and forth with the HV-can (stock on your Reign) and the LV-can (stock for many RP23s).

With the HV can the shock will likely blow through about 3/4 of its travel and then hit the Boost Valve portion at the end of the stroke and will ramp up rather quickly (some say harshly). I experienced this phenomenon just like many others have reported. With the LV can I can set my Boost pressure low and back the Bottom Out to max volume and I have a shock that feels wonderful. Shock travel is metered according to the size of bump encountered, no harshness in any portion of the stroke, and I use full travel on the big hits and drops. On a high leverage ratio bike (your Reign) the DHXA is fabulous with the LV can.

Don't fret about switching cans--takes about 10 minutes (first time should be under 30min if you study Fox instructions on air can service first). It really is super easy. I've switched or serviced air cans on Fox shocks about 20 times in the past year (much of this was experimenting with HV and LV cans on a RP23 and the DHXA). PUSH can probably get you the LV can for $40-60. You just need a "pillow pack" of Float Fluid (probably comes with the air can) and you're set.

Don't back out on the Reign on this issue. I am also thinking about one in the future and my '07 DHXA 5.0 with LV can will be on there in a flash. :thumbsup:
 

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carpe mañana
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daugela said:
I'm not light or a fat ass..I'm a solid 190 pounds with 10% body fat. Now I'm in a real pickle. I want that Reign 0, but not if I'm going to have to replce the rear shock soon with the can.
DHX air is not a bad shock. It is not unreliable, neither. It is an OK shock and works a lot better than shocks have worked say 5 years ago. A lot of us have been spoiled, be it by PUSH or Cane Creek or Avalanche, etc. and there's a certain level of snobbery around here. Would I recommend anyone go out and buy a DHX in any form? No. Is it a bad shock? No. You will be fine on it and probably very happy with the bike.

_MK
 

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mmm
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Dumb question: What's the correlation between the BO knob and BV pressure.

For instance....if I set BV to 170 psi and BO all the way out, is that similar to 100 psi in the BV with BO all the way in?
 

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carpe mañana
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timehoc said:
Dumb question: What's the correlation between the BO knob and BV pressure.

For instance....if I set BV to 170 psi and BO all the way out, is that similar to 100 psi in the BV with BO all the way in?
Only during a single instance of the entire stroke. For all other times, no.

The volume adjusts the progression of the air pressure inside of the reservoir during compression. As the oil gets pushed into the boost chamber, through the boost valve, during compression, the air volume gets smaller. The smaller the volume the exponentially faster the pressure increases (air pressure curve is exponential in nature).

Air pressure in the boost chamber fights the flow of oil into it. You can call it position sensitive compression damping. If the volume is small, the air pressure increases rapidly and you have more compression resistance mid stroke and a metric sh!t load near bottom out. If the volume is large, the air pressure increases less rapidly, having increased mildly during mid stroke and to a considerable amount near bottom out.

The initial pressure essentially sets the pedaling platform level. The pro pedal knob just fine tunes it.

_MK
 

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The Giant reign is a great bike. Here is what you need to do.
1. Buy the giant
2.Buy a Cane Creek double barrell
3. Sell the DHX to some canadian grom
4. Ride

I picked up a 2007 reign 0 in may, I wish I waited so I could have bought the 2008 and put a CCDB on there.
I have a CCDB on my DH bike, best shock out there.
 

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Discussion Starter · #13 ·
That's some great information, but I'm alittle confused. Is the HV can the piggy back can on the Reign 2008 0? I assme it can't be because you said the RP23 is the LV which doesn't use a piggy back. So is the LV and HV thing inside the two.

Help me out here. I'm new - straight from triathlon. thanks
 

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mmm
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MK_ said:
Only during a single instance of the entire stroke. For all other times, no.

The volume adjusts the progression of the air pressure inside of the reservoir during compression. As the oil gets pushed into the boost chamber, through the boost valve, during compression, the air volume gets smaller. The smaller the volume the exponentially faster the pressure increases (air pressure curve is exponential in nature).

Air pressure in the boost chamber fights the flow of oil into it. You can call it position sensitive compression damping. If the volume is small, the air pressure increases rapidly and you have more compression resistance mid stroke and a metric sh!t load near bottom out. If the volume is large, the air pressure increases less rapidly, having increased mildly during mid stroke and to a considerable amount near bottom out.

The initial pressure essentially sets the pedaling platform level. The pro pedal knob just fine tunes it.

_MK
Thanks, its starting to make sense. I currently have the main chamber at 33% sag and BO out knob all the way out (high volume). With these settings I can only get about 45mm out of my 50mm stroke consistently. So, lowering BV (currently 170psi) won't have any afffect on getting that last bit of travel?

FWIW my leverage ratio is 2.65:1, 190lb fully geared.
 

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carpe mañana
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timehoc said:
Thanks, its starting to make sense. I currently have the main chamber at 33% sag and BO out knob all the way out (high volume). With these settings I can only get about 45mm out of my 50mm stroke consistently. So, lowering BV (currently 170psi) won't have any afffect on getting that last bit of travel?

FWIW my leverage ratio is 2.65:1, 190lb fully geared.
I presume you mean lowering the pressure.
It will have an effect. Just not as much as increasing the volume would. But since you're maxed out there, drop the pressure. In my experience 120-140psi of boost pressure worked best with that leverage ratio.

_MK
 

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mmm
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MK_ said:
I presume you mean lowering the pressure.
It will have an effect. Just not as much as increasing the volume would. But since you're maxed out there, drop the pressure. In my experience 120-140psi of boost pressure worked best with that leverage ratio.

_MK
Thanks, I'll try that this weekend. Hopefully this won't affect my PP range too drastically.
 

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'aua e te fati
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I'm 200 and I ride an rp23 on my Jamis XLT and I love it. I think the leverage ratio for the XLT is 2.5:1 if that helps.
 

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Slow Patrol
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timehoc said:
Dumb question: What's the correlation between the BO knob and BV pressure.

For instance....if I set BV to 170 psi and BO all the way out, is that similar to 100 psi in the BV with BO all the way in?
If you are curious just stick a shock pump on the boost chamber and cycle the suspension and watch the pressure change. You will likely have to lower your main pressure to bottom the shock. Yes the attached shock pump changes the boost chamber volume but you can get a relative relationship between settings with this experiment.
 

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mmm
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NormanPCN said:
If you are curious just stick a shock pump on the boost chamber and cycle the suspension and watch the pressure change. You will likely have to lower your main pressure to bottom the shock. Yes the attached shock pump changes the boost chamber volume but you can get a relative relationship between settings with this experiment.
I understand compression will increased the pressure in the BO chamber.

My basic question was does high pressure/large volume equate (or similar) to low pressure/small volume in terms of ride quality.

From what MK says, no. Variations in BO volume will have a much greater affect than BV pressure.
 
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