YTread Logo
YTread Logo

Servicing An Air Shaft In Real Time | Mountain Bike Suspension Fork Service

Jun 04, 2021
- Hello and welcome to another

real

-

time

service

video. This

time

we will focus on the air chambers. (whistles) In the past, we have made very detailed videos on lower leg

service

s. So if this all sounds like dark art to you, click here to watch Doddy's video. It's a very detailed tutorial and a great way to get familiar with what is a pretty basic service. However, today we will focus on our inner tubes. Now, air springs are basically to replace what you might think of inside the

fork

, the spring itself, with just a pressurized air spring. Not only is this very light and very adjustable, making it perfect for

mountain

biking.
servicing an air shaft in real time mountain bike suspension fork service
Now, you'll need a couple of things before we start this service. The most important thing you will need is some circlip pliers. Basically, they are used to remove the air spring from the bottom of the

fork

. You can also use a valve tool here, which is very useful. And some bits that we don't technically need, but are very useful if you want to do the extra layer, and they are a 12mm wrench and an 8mm Allen wrench. As for grease, you can use SRAM's dynamic seal grease, or just something like butter or similar. They recommend it for the inner workings of your shocks and forks, but to be honest, both will do a perfectly decent job.
servicing an air shaft in real time mountain bike suspension fork service

More Interesting Facts About,

servicing an air shaft in real time mountain bike suspension fork service...

And, as always, Mr. Blue Towel, just to keep things clean. So the first thing we need to do is remove the valve core from the top of the fork, let all the pressure out, make a note, take it out and that's it, and store it somewhere safe. You can probably get away with just holding it down, etcetera, etcetera, but I think it's not only easier but also safer to remove it completely, out of the way. You're taking apart some things that can hold

real

ly high air pressures and, yeah, they're not to be messed with. Those things can be pretty sketchy if you take apart something that's even remotely charged, so yeah, be careful.
servicing an air shaft in real time mountain bike suspension fork service
Now, first things first, let's get our circlip pliers, which may not be part of the bread and butter of many tool boxes, but they certainly come in handy, especially for

suspension

. I suppose you can use two selections, but this will make it much, much easier. Now, at the bottom of our inner tube, we have this retaining clip that we're going to get to with these. So it's forced down nice and even, and it comes out like this. Now this service we're doing is a great little addition to your lower leg and will really help increase the performance of your fork.
servicing an air shaft in real time mountain bike suspension fork service
There's a lot of attention here on these seals, these wiper seals and how they might reduce friction, but the diameter is also quite large and having that big air spring, you need to lubricate it, you want to make sure it's nice and light in terms of of action. Also, this is the part you replace if you want to change the travel of your fork, so it's worth keeping in mind. Now what we need to do here is empty the positive air chamber, and it's definitely empty because the valve core is there, but the negative one may still be charged.
So while we're going to accomplish this, there might be a little pop, so please don't do it. It's like in the cold cartoon, the guy looking down the barrel of the gun. Maybe I'll do it away from you. (pop) pop. Hello, done, and there we have it. If you were to take out this upper assembly here, where the volume spacers are located, you could see straight down the fork. It's really as simple as that. So the way it sits is here, is where your positive air chamber is. It evens out, since the fork has a little notch in there, to fill the negative.
Now, negative inner tubes are a big buzzword in

mountain

biking right now, and the original assembly isn't here. It usually comes with this spacer right on the inside. This is a top spacer. It means that when the fork reaches full extension, it doesn't make any noise, it's nice and smooth. However, if you want, a little trick you can do if you want Pike, like these, or even later generations of RockShox forks in general, is to remove this, which increases the volume of your negative air. which will help a more agitated stroke throughout the entire route. So that's a nice little tip, and it's not something you have to do, but I mean, to be honest, the forks are very active anywhere in their travel anyway, but yeah, it's a nice little trick, and if you want to remove That, you can just put the 8 mil in there, a wrench on the end and that's it.
That requires a small amount of retaining compound on what is a very fine pitch thread, but yes, it's worth doing. I'm just going to... Take that away. And that whole set can slide in there. This is where you'll need to remove the bottom spacer or install it, depending on how you go. Which I'm going to do, because why not? Why not do it as best as possible? And I'm just going to use SRAM butter for simplicity. Just a little grease, make sure it's clean before you go in, and you can get special tools that will allow you to grease it more effectively.
It's like a bit, almost like a bullet that's shaped on the end, which is absolutely lovely, but you can make it at home very easily, just like I'm doing here. I'm just going to make sure my finger is nice and clean. Slide it in the obviously correct orientation. The writing should be at the bottom, and it will be very similar no matter if you want Fox or whatever. It's something very similar. Like I said, this is the part you need to change if you want to change the travel of your fork in the later generations. Yes, keep in mind that it's a really simple service, like I said, and on some forks, like Suntours, they use spacers that clip onto this leg and they are largely the same thing.
Now... I also said before that sometimes they use retention compounds there. I separate my forks pretty regularly, so for me it's not a big deal, but if you're a set-it-and-forget-it kind of person, then maybe it's worth doing. Bitten nice and firmly there. If you have a torque wrench, you can check the manufacturer's guide on the website, but I think we'll be pretty good there. And there we have it, that nice, sealed and lubricated. It definitely feels pretty light and at that point we're going to lubricate this seal here. I'm going pretty steady. Sometimes they come over lubricated, like a very generous helping of new grease, and what that means sometimes is the equaloi...
Equalization port, the equalization port? The equalization port, which is there on the fork, gets blocked with grease and that means that sometimes the negative air spring can become overloaded and can't return to the positive. That's when the forks get stuck, so if that's the case then this is the service to do, although when you take it out there can sometimes be a big pop, so it might be worth covering it with a little cloth or similar. Next, okay, I'm going to hold this up to the light and illuminate it. The light is a really useful tool as a way to inspect and make sure there are no nicks or scratches.
From there, there shouldn't be much, but it's a good habit. Always inspect your things for wear and tear. As you do it, you'll become more familiar with what it should look like, with tolerances and things like that, so it's definitely worth doing. And then, holding it nice and steady, try to get it in. Here we go. So this part is really important, because if this circlip is not installed correctly, then you are going to have a lot of problems, right? So let's make sure it's seated properly and there's a definite click. There we are simply going to remove the excess fat.
This will help us in terms of visual inspection, and there is definitely a defined slot for this circlip to fit into. So we got it there. We're going to lift our fingers, hold it in place, hold it down and it's that simple. It's installed very well, and make sure it's fully seated, nice and flat, parallel to the top. If it's tilted, it's not positioned correctly and like I said, it could go a little wrong. So, very simple, we're going to reinstall this valve core, making sure it's clean. I'm just going to be a little naughty. It's almost like dinner, double dipping. (whistles) Politics, man.
So let's put that in there. The reason I really like to lubricate those seals is that it just reduces any kind of micro-tearing that can occur and really just covers the bases. So there we have it. Now, as we inflate this positive air chamber, this leg will go back to where it was. Now, a really good guide to inner tubes, there's something called bushing overlap, which is basically how far the bottoms and fork legs mesh together and how deep they sit in there, which is obviously very important. , but another visual guide. What you can do is if your air span is longer than your shock, so it's way out, then what happens is when it gets to the top of its stroke, it's actually going to separate that shock, so which can cause serious problems. damage to your

bike

, and when we change the length of our forks, that's something we really need to be careful of.
So we always want to make sure, even when they're in full extension, that the shock is a little bit longer than the air leg, the air duct. But that's it, and you'll be surprised at how much of a difference this will make, and it only takes a few minutes to do. Now, is this something you do all the time? Let us know in the comments below. As always, don't forget to like and subscribe, and if you want to see the other real-time service we've done, which is where we dismantle a RockShox rear shock, click here. It's a little fun, a little silly, I just keep yapping on and hopefully I can throw in some tips and tricks you maybe didn't think about.
Awesome, thanks for watching guys.

If you have any copyright issue, please Contact