My old RST First Air 100 Lockout (year 2010) fork has had a stuck lockout for some time. This fork has never been serviced so it is probably just damaged beyond repaired, but I am just researching if there is any point trying to save it somehow without investing too much money in to a morally obsolete 26" V-brake bike.

The fork still working, the pressure can be adjusted by an air pump, but the lockout is stuck in the open position and and the lockout lever cannot be turned.

Also, if I were to try to service/replace just the minor parts, like the seals and dust covers and oil, and leaving the lockout alone, which set of parts would be the right one to get, if there is any available at all?

I fear that just by bringing the fork to an LBS I would soon be over the price of a new coil-type fork that can be bought around 55 EUR.

  • 1
    The RST air forks do usually have complete replacement dampers made for them. I've only done one of them, a situation where the lower leg attachment threads got stripped. Installing it was pretty straightfoward once obtained. Being a grease fork, it was a matter of taking out the old one, cleaning and slathering everything in grease, then putting the new one in. A starting place could be reaching out or having a shop reach out to the RST distributor in your country and seeing if they have it or if not, if they'd be willing to let you know what part number it is so you can google it. Mar 27, 2023 at 16:23
  • Hm, that sounds like a no go. I can't seem to find any dampers at all, the less for an old fork. The only thing I am able to find are O rings, quite expensive for a few pieces of rubber. This is a 2010 bike, so reaching out to a distributor who does not have any dampers on their website rstmtb.cz/produkty-kategorie-prehled/48090 sounds like a futile effort. Mar 27, 2023 at 18:28
  • IMO, RST forks were always low end (I'm happy to be corrected). While probably able to be fixed, considering they are 13 yrs old and never been serviced, they don't owe you much. I wouldn't waste time and just got straight for a replacement. Although that said, how much of a problem really that you can't lock the fork out?
    – Hursey
    Mar 27, 2023 at 19:39
  • Parts of this sort don't always make it into sites or literature, but can sit around warranty departments for a long time. Mar 27, 2023 at 22:41
  • Yes, I understand that, but for a bike with an almost zero rest value it is not worth going into such pursuit. Also, as Hursey points out in the above comment, the fork is still rideable, just not locking. Mar 28, 2023 at 13:31

1 Answer 1


Most likely reason is the damper is broken somehow. As said by @Nathan, these are a replaceable part. I do not believe they are serviceable beyond replacement. Sourcing a replacement will be the problem, ad it may not be economic to do.

If you look at options, probably the best one is service the fork and ride it without the lockout. Adjust the air pressure to suit you riding. While lockout can be useful if you ride varied terrain (e.g. I use mine when I ride the roads to the MTB park, when its unlocked), you can use air pressure to set a compromise that will out perform a cheap coil fork, and if you terrain is mostly fairly consistent, set air pressure to suit.

Replacing the damper would only be worth it if the rest of the fork is in good condition and the damper can be sourced at reasonable cost. After 13 years with no service this is unlikely, although if you can find a donor bike/fork that matches, you may be able to use the damper from that one.

Replacing the fork with a new one is almost certainly uneconomic. The bike would have been classed entry level with RST fork, with the rest of the bike being entry level a new fork will likely cost more than the bike is worth. You may be able to pick up a donor bike fork from a recycle center or other sources. I know where I live a replacement fork for my well maintained, carbon 2010 Scott Spark would cost more than the bike is worth, and that was a $US4500 bike when new.

Replacing the bike might be the most economical solution. The broken lockout will reduce the current bikes sale value, but it is still a bike that can be ridden. Put finds raised form sale and funds you would need to replace the fork into a replacement bike.

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    The main reason for not replacing the bike is that I do not have a new 1500€ bike in an unlocked shed somewhere in the countryside where I only come for certain weekends. But I will think about some second-hand options. Mar 28, 2023 at 13:33
  • I disagree with the "uneconomic" argument. Used, damaged bikes are "worth" very little because somebody looking for a bike doesn't want to buy something where they don't know how well it has been taken care for and if half the parts will break after 3 months. But if this is your own bike and you know you've maintained it well, then it's perfectly reasonable to assign it a higher personal value. The replacement parts may then still be more expensive than a new bike, but they may also result in a significantly better bike than you would get new. Mar 30, 2023 at 8:26

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