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Lower Leg Removal Issue

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wilbersk

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Discussion starter · #1 ·
I’m attempting to service my fork solo for the first time, and I’ve run in to an issue I need help with. I followed instructions step by step, but I’m having trouble when it comes to pulling them off.

When the lowers come off, only one of the shafts is present. So I put the lowers back on, (to attempt to put the bolts in a little and try tapping again), but the shaft that’s the issue is too far in the lower leg to hook up the threads with the bolt.

Not sure if that makes sense but I’m not sure how else to explain it. Did I tap the bolts too hard? And how do I proceed forward now that I can’t get that bolt to hook up?
 
#4 ·
Wait. You're saying the side that was stuck and needed to be hammered on a bit more to release the press fit with the lower... is already disconnected from the lower by enough that you can't even get the bolt to thread in?

Doesn't that mean that the whole reason you are trying to thread it back in (to get it loose)... is moot?

Either way, it sounds like the air spring still has pressure in the negative chamber, making it "suck" back in a bit. Either that, or your fork is running less than its max travel, and the air spring side is just shorter than your damper side.

I had a breif moment of confusion when I was servicing my fork yesterday, and realized that the damper side is always going to be longer than the air spring side for my fork. As the damper is long enough for a full 180mm of travel, but my fork has a 160mm air spring.

So I had to put the lowers on, and compress the damper side by 20mm before the spring side could find threads. I'm assuming thats what is happening to you right now.
 
Discussion starter · #5 ·
ocnLogan said:
Wait. You're saying the side that was stuck and needed to be hammered on a bit more to release the press fit with the lower... is already disconnected from the lower by enough that you can't even get the bolt to thread in?

Doesn't that mean that the whole reason you are trying to thread it back in (to get it loose)... is moot?

Either way, it sounds like the air spring still has pressure in the negative chamber, making it "suck" back in a bit. Either that, or your fork is running less than its max travel, and the air spring side is just shorter than your damper side.

I had a breif moment of confusion when I was servicing my fork yesterday, and realized that the damper side is always going to be longer than the air spring side for my fork. As the damper is long enough for a full 180mm of travel, but my fork has a 160mm air spring.

So I had to put the lowers on, and compress the damper side by 20mm before the spring side could find threads. I'm assuming thats what is happening to you right now.
Click to expand...
I'm not at home at the moment, but I'll take pics when I get home. It basically looks like this after I take the lowers off.

Image


It's a 2019 RockShox Lyrik Charger 2 RC2 170mm
 

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#6 ·
So the lowers are all the way off then? I thought you were having a hard time getting the lowers off, but thats a reading fail on my part.

If the lowers are off, why are you trying to tap on the bolts? You only need to tap on the bolts to get the spring and damper to "disconnect" from the lower, so you can slide the lower legs off. Once the lowers are off, there shouldn't be any "tapping".

With the lowers off, and the air pressure out of the spring side (take out the valve core, makes it much easier), you should be able to move the air spring/damper shafts pretty easily by hand.

And if one of them is bottomed out/"disappeared" in the uppers, you can thread the nut in, and pull on that, and it should slide right out.
 
#7 ·
Pump some air in the fork with your shock pump. That will extend the air side allowing it to fit through the lowers hole to thread the bolt. You don’t really need to take air out of fork to just service the lowers. Only if you are taking off the top cap.
 
Discussion starter · #9 ·
ocnLogan said:
So the lowers are all the way off then? I thought you were having a hard time getting the lowers off, but thats a reading fail on my part.

If the lowers are off, why are you trying to tap on the bolts? You only need to tap on the bolts to get the spring and damper to "disconnect" from the lower, so you can slide the lower legs off. Once the lowers are off, there shouldn't be any "tapping".

With the lowers off, and the air pressure out of the spring side (take out the valve core, makes it much easier), you should be able to move the air spring/damper shafts pretty easily by hand.

And if one of them is bottomed out/"disappeared" in the uppers, you can thread the nut in, and pull on that, and it should slide right out.
Click to expand...
So I think what's going on is that I didn't get the air out of the negative chamber of the air spring, so the air spring shaft doesn't want to come out from the uppers. I'm going to try and remove the valve core like you suggested so I don't have to start over.
 
#12 ·
F.N.G said:
Pump some air in the fork with your shock pump. That will extend the air side allowing it to fit through the lowers hole to thread the bolt. You don't really need to take air out of fork to just service the lowers. Only if you are taking off the top cap.
Click to expand...
This is the answer. Just pump some air into it.

You are right. The negative air spring is sucking in the post. This chamber is separate from the positive air chamber and only equalizes when the fork is cycled, which likely is too difficult to do with the lowers off. Put some air into the fork and it will push the post back out. You can air up the fork without the lowers being on.

Next time if you want to take the air out of the fork, you need to do it in stages. Let a little out, then cycle the fork a few times, then cycle, let more out, etc. This will empty the negative air chamber. But as has been said, this isn't really necessary if just servicing the lowers.
 
#14 ·
There is an equilization dimple in the fork stanchions. When the seal on the air spring goes over that dimple, the air pressure in the positive, and negative sides are equalized.

What sounds like it happened, is you emptied the entire positive chamber all at once, and the spring didn't have a chance to cycle past the dimple and equalize as you depressureized it. This basically means you have huge pressure in the negative spring right now, who's job is to pull up on the spring (to help overcome the stiction of the air spring seals).

So like kpdemello said, just pump it back up to normal, then depressurize in stages while cycling the fork through the first 1/3 or so of its travel. That will allow the negative air spring pressure to lower at the same rate as the positive, then you should be able to remove it easy peasy.

Good luck :).
 
Discussion starter · #16 ·
After putting the lowers back on, airing up the fork, and trying to take the air out the proper way, I’m still having the same result. When I remove the bolt from the air spring side lower, you can hear a “thwack” as the shaft gets sucked back inside the uppers. So there’s still air in the negative chamber.

Do I need to get the bike out of the stand and put the front wheel back on in order to properly take air out of the fork? I can’t think of what else to do.
 
#17 ·
When you put the lowers back on and put air back in, was the fork still sucked down in its travel some? Did you cycle the fork after you inflated it?

Because it sounds like the air isn’t transferring from the negative to positive air springs. Which either means you aren’t cycling the fork through its travel enough (from full extension, down to about 30% travel) when depressurizing it, or the transfer port is plugged somehow.

If you’re having a problem cycling the fork, then putting the wheel on and actually bouncing around on the bike will help you do that.
 
Discussion starter · #18 ·
No, when I put air back in it extended to it’s normal position. I’m going to try putting the wheel on and depressurizing the fork again, because I’m not getting it out apparently cycling it by hand.
 
#19 ·
Yeah, cycling a fork with actual air pressure in it by hand is nearly impossible, unless you’re the hulk.

Just take it in stages, and bounce on the fork with your whole body weight a few times each time you let out some pressure. Just remember, you’re wanting to cycle the fork through full extension, to about 30% travel.

Good luck!
 
Discussion starter · #20 ·
ocnLogan said:
Yeah, cycling a fork with actual air pressure in it by hand is nearly impossible, unless you're the hulk.

Just take it in stages, and bounce on the fork with your whole body weight a few times each time you let out some pressure. Just remember, you're wanting to cycle the fork through full extension, to about 30% travel.

Good luck!
Click to expand...
Thank you so much for helping me through this, but still not much luck. I put everything back together, let the air out in 4-5 stages (stopping to hop around on the fork each time), and it's a little better but still not right.

Now the air spring shaft isn't suctioned all the way in the uppers, but it's still having a lot of resistance trying to pull it out.
 

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