Fixing my Fork

Hi I currently have a sr suntour aion and I’m done with it it’s very frustrating and just stiff even with the air set up correctly, about 10mm of dead travel ( it’s not the sag even when I’m off the bike it’s dead ) and just not plush at all. I have tried everything to try to fix it nothings working need help :joy:

By dead travel, are you talking about stiction? The fork doesn’t break free until you hit a significant bump, and then lets go? You could try some fork lube. Clean the stanchions really well, down to the seals, and then try lubing. I have used a teflon (dry conditions) chain lube, but there are fork-specific lubes out there:

Note: I linked to MEC, but the website says they don’t stock it in Halifax, although it can be ordered. LBS’s would carry fork lube.

Well it has about 10 mm that is just in the legs of the fork like if I were to push on the spot where you could mount a mud Guard and pull at my handle bars it would come up 10mm or so and it’s not plush at all I don’t know what to do

And yes it doesn’t really move unless it’s a big impact I’ll take it apart and clean it out and try some of that stuff but how do you apply it

That sounds like a pneumatic top out, stops the fork from topping out when you pull up on the wheel. Some forks have a mechanical top out bumper (rubber bumper inside), others have a pneumatic bumper that relies on the air in the fork to stop it from topping out. It’s completely normal and nothing to worry about.

Do not take anything apart. Clean the outside of your fork thoroughly, specifically the seals and stanctions, and apply that lube to the stanctions. The bottle should have instructions on it telling you what to do.


Ok thanks

when did you buy the bike? Could be that the oil in the fork is meant for a heavier rider and so even with it fully open may be over damped for you. How is the rebound? Did the negative air chamber balance out? I know with rear shocks if u don’t pump them up properly they will suck down.

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Sounds like you should bring that fork into a shop and have it looked at by a professional… could be damaged or could just need a rebuild.


@Evan29 I checked out a few reviews and the Aion seems to be a pretty decent, sealed damper air fork. Maybe it has too many volume spacers installed in the air chamber?


The rebound is set as fast as it can and it’s still slow and yes I got it new on the bike it’s a 2018 I got the bike Last summer

Should still be under warranty then, it might be worth going back to the shop you bought it from to get them to check out/warranty.

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For sag, the manual says you should be running 15-30% of your travel. Recommended pressure for your weight is on pg. 7 of the manual here:

That pressure is a starting point, then adjust to achieve your desired sag.

You’ll need a shock pump to check it and adjust air pressure.

Even if your sag is set right, if you’re a lightweight, there just might not be enough force to overcome the stiction unless you do a hard hit, so the fork lube may help.

There may be volume spacers that can be added or removed to adjust the travel, but unless you know what you’re doing, I’d let your shop do that.

Before you give up on the fork, I’d stop in at the shop where you got the bike, and have a chat with them and see if they have any suggestions, or if there’s some adjustments they can do.

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Soo the difficult thing is i bought the bike in Calgary and i wont be going there anytime soon and i can check to see if theirs any volume spacers but i was going to do that about a week ago but when i take air out it spits out some liquid out of the valve so i dont know if thats normal or a problem

i’ll check out the volume spacers but is it suppose to spit out liquid when i take air out

You don’t have to bring it to the original store for warranty coverage. If I recall, you ride a Giant so just bring it into Giant Halifax and let them sort it out. Even if it’s not a warranty issue, best to let a pro fix it if you’re not sure what the problem is.


Ok thanks

Volume spacers for changing the positive air chamber volume which controls how fast the fork ramps up towards bottom out resistance. I think you were thinking of travel spacers.

Too many volume spacers in the air chamber is going to make the fork harsh and ramp up too quickly.

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When you let the air out it’s normal for a small amount of oil to also come out. A little push on the valve and the air should release quickly. You don’t need to compress the fork with the valve open or a lot more oil is going to come out… you don’t want that. You just want to release the pressure.

Ok thanks a good amount of oil comes out but if that’s ok then all good

If there’s a significant amount of oil- like more than a few drops then it may indicate that your air chamber has more oil in it than it is supposed to. It could have been overfilled at the factory or migrated from the lowers up into the oil chamber. That will make the fork extremely progressive and hard to get much travel out of. It’s not that uncommon- I’ve experienced that with one of my Fox forks.

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