Hi. I have a friend with a Trek 820 hardtail mtn bike. He lives in an apt. and left his bike on the patio...and it was rained on. Now his front fork is siezed, although there is no visible rust. Any suggestions on how to attempt to break it loose without damaging anything? I'm not familiar with the internals of his suspension...I think it's a RST 191 C7, 63mm. We need to get this thing moving again so we can ride this weekend. Thanks!
new fork. The RST's are hard to find parts for espesially on the low end ones. Its about a 60 dollar fork if that. you could try spraying a bunch of penetrating lubeon the upper tubes to soak down inside to maybe break the corrosion free.
First of all, this sounds to me like the fork has not been maintained at all really. A fork in good condition should not just "freeze up" just because it was left out in the rain. If this was the case, no one would be able to ride in anything but dry weather. But, you can do try a few things here...
1. Remove the top caps and remove the spring/mcu assembly, then turn the fork upside down and see if any water comes out.
2. See if the fork will compress without the spring/mcu in it.
If it does...work the fork up and down while spraying some silicone based lube in and around the stanchion tubes. It is important to use silicone as it will help displace water and won't destroy any seals in the fork.
If it does not compress, you've got more work ahead. You can try to tap the stanchion tubes with a rubber mallet, but not too hard.
If this does not free the fork, you will need to have it completely taken apart and examined, cleaned and reassembled. I don't know how technically savvy you and/or your friend are, but this generally requires some special tools and a pretty good idea of how the inside of a suspension fork works. For this level of fork though...he'd be better off just buying a new mid level fork. They're on sale everyday of the week somewhere.
Thanks for the input, guys. I plan on messing with it a little bit Friday...and no, it hasn't been properly maintained. Both my bikes are kept indoors and are well maintained....I would NEVER think of leaving them outdoors for storage. I thought of gently pulling the seals back and spraying some rust penetrant in the tubes- then try to work them a little. I'm a Honda tech, so it shouldn't be too difficult to tinker with, I just wanted to know what I was up against. Tools aren't an issue, although I have limited specialty tools for bikes. I appreciate the info...He's gonna bring it to work in the morning so I can mess with it up there...I'll let you know what comes of it. He may end up visiting our LBS.