Why does Amflow say no coil shock on the new PX? What would really happen if I run an Öhlins TTX22m.2 Coil?

[FlorianLanua]

Hi all,

I have a question mainly for Amflow or for anyone who really understands the PX frame and suspension kinematics.

On my current Amflow PL I run an Öhlins TTX22m.2 Coil, and honestly it has been excellent. I ride mostly XC / trail, no big jumps, but a lot of rough off-road terrain, gravel, washboard, roots, small harsh rocks, and some bigger stones too. I also have back and knee issues, so comfort matters a lot to me.

Now I have ordered a new Amflow PX XL, and I noticed that Amflow says coil shocks are not recommended on the PX.

What I want to understand is the real technical reason.

• Why exactly is a coil shock not recommended on the PX?
• Is the issue the leverage curve, bottom-out behavior, frame stress, or something else?
• What would actually be the downside if I install an Öhlins TTX22m.2 Coil 210x55 anyway?
• Is this mainly a warranty / liability statement, or is there a genuine performance or durability problem with the PX frame design?

Again, I ask this because the TTX22m.2 Coil feels fantastic on my PL, especially for comfort on rough terrain, so I am trying to understand why the PX would be so different.

I would really appreciate a technical explanation from Amflow or from someone who has real experience with both PL and PX.

Thanks.

 

[Brawwp]

Where did you read you shouldn’t use a coil shock at? Can you post or link it? They used to give specific coil shocks that work well on the bike. I run ext storia v4 on my pl carbon.

 

[FlorianLanua]

Where did you read you shouldn’t use a coil shock at? Can you post or link it? They used to give specific coil shocks that work well on the bike. I run ext storia v4 on my pl carbon.

I found this wording in Google’s snippet for the official Amflow PX FAQ, although I can’t currently see the same sentence in the live FAQ body. This is what they write-
“Amflow PX comes standard with an air shock, and installing a coil shock is not recommended. Doing so may cause frequent bottom-out or abnormal frame stress.”

 

[Brawwp]

I found this wording in Google’s snippet for the official Amflow PX FAQ, although I can’t currently see the same sentence in the live FAQ body. This is what they write-
“Amflow PX comes standard with an air shock, and installing a coil shock is not recommended. Doing so may cause frequent bottom-out or abnormal frame stress.”

So google not Amflow?



This is from Amflow. It’s just saying make sure it doesn’t interfere with the frame not that you can’t use a coil. They used to specifically recommend ohlins, ext, and something else. You’re good going coil.

 

[FlorianLanua]

So google not Amflow?

View attachment 185277

This is from Amflow. It’s just saying make sure it doesn’t interfere with the frame not that you can’t use a coil. They used to specifically recommend ohlins, ext, and something else. You’re good going coil.

 

[Plummet]

The kinematics are probably too linear for a coil.

 

[Brawwp]

View attachment 185278

Click the link. They must have taken it down. Their faq does not state that anymore. I’d screen shot what it says now which is to just make sure it doesn’t hit the frame then hopefully they won’t give you any trouble should you need to warranty it.

But dude keep the stock shock. How they gonna know?

 

[Brawwp]

The kinematics are probably too linear for a coil.

No way it changed much from the pl? This is screenshot from the pl carbon faq

 

[Fangs2k]

I think what Amflow were saying in the FAQ from the Google search was just that a badly setup unsuitable coil shock that would blow through its travel with frequent bottom outs wouldn’t be recommended.

Same as with a badly setup air shock then.

It’s just a recommendation, probably based on arse covering for liability reasons, but there’s no reason a properly sized, sprung, valved, and damped coil shock shouldn’t work great on any bike.

 

[Powerslider]

Sounds to me like Amflow is clearly saying an air shock is a better match than a coil in the PX. The PL is a completely different bike so a coil working well on that means nothing.

 

[Brawwp]

Sounds to me like Amflow is clearly saying an air shock is a better match than a coil in the PX. The PL is a completely different bike so a coil working well on that means nothing.

That’s because the air shock that comes on an amflow is tuned for it. Nothing to do with one not working well. It’s the same style suspension design. They say the same thing on the pl. No bike company is going to encourage you to change the shock on their bike when they don’t sell frame only option. They are trying to let you know this is what they think is best. They also don’t want to encourage modifications by people that probably don’t know what they are doing.

Ext has a specific amflow tune for their coil shock as well.

 

[Brawwp]

 

[MetroNeck]

Apart from bottoming out, the yoke design sideloads the shock quite a bit. At best, this scratches the inner body (would need replacement), at worst you snap the piston.

 

[KTMJack]

Specialized has the same type linkage If you use a shock will a small shaft it will snap
I went with Push coil and coil forks now its way smoooth