Stuck Specialized Suspension Fork
 

Today I bought a used Specialized Rockhopper FS for my son. The bike is probably quite old, but in very good conditions (it could use new pedals). However, the front suspension shocks (with stickers "Rock Shox" on them) are completely rigid. No matter how hard I push or pull, they do not move at all. There's a hand screw at the top of each shock. I can turn it by hand a couple of turns, but that changes absolutely nothing.

I don't think this is correct. What are my options?

Photos might be useful

It's probably an elastomer fork and the elastomer has hardened (or in compressed, non elastic state due to age and wear).

chances are that water has gotten inside the fork and it is now rusted in place. Tip the bike upside down, walk away for a while, and see if anything leaks out of the fork. do this where the leaking stuff WON'T stain anything... it will be black water and grease mixed in it.... it usually stinks, too. I toss down an old towel to catch the gunk.

If any of the control cables are stuck, that's another sign that the bike has been out in the rain... Replace those cables and the chain is usually funky too. Cables are cheap compared to emergency room visits :rolleyes:

i have gotten some old stuck forks to move again, but they weren't in what i'd say was usable condition..
IF you can get them to move, then you might be able to take them apart and clean all the gunk out, re-grease, then slip them back together.

Youtube has a bunch of fork cleaning vids...

take a few pics of the bike and fork, then post them here... it will help a lot ;) there's about a thousand different forks., half of which are probably low end Rock Shox or RST's, with either Elastomers (BAD! Usually No Kits Available) or Springs (Better for you, and Rebuildable, USUALLY) in them.

1" or 1 1/8" steerer tube, threaded, or non-threaded steerer tube, sealed oil damped, or vented(grease lubed), etc.Some require some fairly specific tools to work on them properly...
Someone here will recognize which style you have.

And if it is an Elastomer (AKA: Poly Inserts) fork and you FIND kits,. let the world know... i have three gorgeous Answer/Manitou forks, and at least two cool old magnesium Rock Shox tapered forks here, just begging for some new bouncy stuffings!!!

Try this place when they come back online....

https://www.suspensionforkparts.net/eshop/

Check if your forks have a "lockout" feature which prevents the legs from moving. Not knowing what forks you have I can't tell you where the lever/knob would be if there is one.

Thanks for the replies. I watched the youtube videos and taking apart the forks isn't that easy.

Here are a few pics. I can't tell whether the fork is stuck in the up or down-position, or somewhere in-between. I cannot see any locking mechanism. What are the two knobs at the top of the fork supposed to do?

https://cimg0.ibsrv.net/gimg/bikefor...20983a55c3.jpg
https://cimg1.ibsrv.net/gimg/bikefor...104e569e66.jpg
https://cimg2.ibsrv.net/gimg/bikefor...4bc509b143.jpg

It could be a Quadra or Mag fork, I'm leaning towards Quadra 10. Looks like the stanchions are in the up position. You can pull up the boots and see if there are obvious signs of corrosion by the lower seals, but most likely the stiction is happening inside the lower legs. It's either corrosion or elastomers gone hard over time. Either way, the fix is to take the fork apart and replace the internals, and chances are you won't be able to source replacements. I would recommend not sinking any time or money into it. It's a threaded fork but if it has a 1 1/8" steerer you can replace it with a different 26" fork with cantilever posts, and maybe take the opportunity to switch to a threadless headset as well.

The knobs at the top are to adjust compression. If it's a Mag, then it'll be an air fork, and one (or both) knobs can be removed to reveal a Schrader valve or needle port (like on a basketball) for inflation/tuning. I don't think those forks had any rebound adjustment.

Edit: looks more like a Quadra than a Mag. Definitely not a Judy due to the lowers. It should be pretty easy to take apart, but there still may not be an easy fix.

looks like a "1 1/8" threaded" to me..

option 1...get a Headset, newer fork that has a long enough steerer tube, an 80mm to 100mm stem with 1 1/8" clamp, and the handlebar clamp size will be 25.4mm, most likely. Easy for bike mechanics, kinda tough for a newbie....... if there's a co-op near the OP, i'd suggest that they go there for parts and help.

There's a chance that someone has over-pressurized the fork.. a chance.... most likely stuck though... a shame.. they were fairly light and worked pretty well.

tothedude.. option 2... try supporting the handlebars so that nothing gets damaged while the bike is upside down.. remove the front wheel.. lay a 2x4 board across the fork bottoms.. and SMACK that sucker with a big hammer... see if it moves.. it's in the extended position, from what i see.
and have you tried Draining any water out of the forks? that also requires inverting the bike....

blunt reality time... i have to toss out a few of that style/age fork every year... sad but true.

Wow, thanks a lot.

It looks like it's a Quadra 5 (or 10?). There are some on eBay for prices between $10 and $200...most of them are described as "stuck", or "elastomer hardened".
Here's a working one for $65. Tempted.

Like an idiot I bought this bike without knowing anything about suspension forks, not realizing that the fork is the most important part of the bike that goes bad over time.

ride the bike as-is
don't buy bikes that don't work

Belay that. DO buy bikes that don't work, that's how you learn.

oh yeah good point. you reminded me of all the cr*p bikes I bought to build 1 good one & then had to get rid of all the extra frames, wheels & other parts

maybe the OP can find a similar bike with a good fork but other problems & swap the fork?

I'm on the fence. I have a threadless Quadra 5 sitting here...

not quite 'sitting" but you get the idea
https://cimg0.ibsrv.net/gimg/bikefor...d10723fb7a.jpg

Not at the lower end, Rock Shox only really got the Quadra right(ish) with the 21R (and that only lasted a year or so before being replaced by the Judy), the 5's/10's really aren't worth putting any money into today, unless you MUST have the period correct part, just replace with something current with 80-100mm travel/rigid, your probably need to replace the headset/stem, but that normally is benificila as it opens up options for getting a better fit with the bike

Confirmed it's a Quadra 5.
I found some youtube videos that explain how to take the forks apart. It's not that hard. I have ordered the long 5mm hex key already. If all the parts inside the fork are present, I may only need new elastomer sticks (any idea where to get those?). I will attempt this on the rainy weekend.

Drop-in replacement elastomer rods for that fork (or really any of that era) haven't been made in decades. Some specialty shops may have NOS replacements in stock, or they may not. A Google search for "elastomer rods" returns many products that may or may not be modified to work with that fork. You'll need to match the dimensions and material properties to the existing one from the fork. As many have mentioned, that fork really isn't worth fixing and you'll be better served going with a replacement fork altogether. Note there could be other incidental upgrades required such as going with a threadless headset, and switching to v-brakes unless you find a replacement fork with a canti hanger.

This was posted earlier in this thread... I'd give them a n email andsee if they can help out.

Quote:
Originally Posted by maddog34 View Post
And if it is an Elastomer (AKA: Poly Inserts) fork and you FIND kits,. let the world know... i have three gorgeous Answer/Manitou forks, and at least two cool old magnesium Rock Shox tapered forks here, just begging for some new bouncy stuffings!!!
Try this place when they come back online....

https://www.suspensionforkparts.net/eshop/

Let's see what I find when I take the forks apart.
Matching material properties exactly is probably not really needed.
I have also seen that there are sets of springs to be inserted in the forks. First, they are pricey around $50. Second, it's a challenge to find some for Quadra 5.

Suspensionforkparts is back online and they have replacement elastomers for Quadra 5.
BUT they are $70 (incl. shipment)! Seems like an awful lot of money for two polymer sticks.

Bring the fork to the workshop, it should be served.

Mystery solved. This is why the shocks were stuck...


https://cimg7.ibsrv.net/gimg/bikefor...75fc3ee022.jpg
https://cimg8.ibsrv.net/gimg/bikefor...83b697ecf6.jpg
https://cimg9.ibsrv.net/gimg/bikefor...05509bb4f4.jpg
https://cimg0.ibsrv.net/gimg/bikefor...41507f14d7.jpg
https://cimg1.ibsrv.net/gimg/bikefor...72f7232d4a.jpg
https://cimg2.ibsrv.net/gimg/bikefor...7c3ba2513d.jpg

The elastomers are actually in good condition, they cleaned up like new.
It was hard to disassemble the shocks. First, the 9" tool I ordered from Amazon turned out to be too short. So I had to put one together like in the youtube video, out of a long 5mm hex bit and a 3/8" extension. Harbor Freight unfortunately does not have those, so emergency trip to local HomeDepot, I am out of $35. Second, in the Husky set of hex bits, the 5mm one (of course) had a machining defect: little metal lips were left in the driver hole, so I had to punch them out before I could use it. Third, the bottom screws were really hard to remove. I was afraid I would strip them, but it worked out.

Now, any suggestions on how to clean that white, hardened residue?
Also, I want to replace the 5 mm hex screws, but they may be hard to find here in San Jose...

if there's an army Surplus store in your area, they usually have gun bore brushes that will get some of that water corrosion out of the tubes... Ebay usually has some options too.

Penetrating oil after an initial cleanout will help too. I use a wire wheel on a bench grinder for external corrosion... The Internal corrosion can also be removed using a Flapper made from a steel rod, cutting a slit in one end, then slipping a foot or so of Emery Cloth into the slit... roll it up the right direction, slip it inside the fork tube or lower tube, and CAREFULLY spin it with a variable speed drill motor... check progress frequently, and don't Over-Clean..

You're beginning to see why i mentioned just getting a different fork, and getting help from a shop.... That said.. go for it, you're half way there... And the tools will come in handy in the future.

The hex screws will be the easy parts. 5mm hex socket in the screws, right? Ace Hardware, etc. has an amazing collection of such things. the THREAD size is most likely 6x1mm. I recommend Stainless steel replacements... no rust that way. The Grease used in these forks is a Rock Shox Grease called "Judy Butter"..Ebay or a bike shop should have it... Coat the elastomers and parts lightly, Do NOT Overfill the forks with grease. Other greases may end up turning those super rare Elastomers into sticky Goo.. Lithium Grease is Specifically Mentioned to Not Be Used by Rock Shox. any seals will need a light coat of Judy Butter too...

The forks got water in them because of bad seals and neglect (leaving the bike outside in the rain)and/or pressure washing it.

maddog34 thanks for the suggestions.

I found the screws at HomeDepot, after realizing at the last minute that I needed M6 screws, not M5. But the length is a bit off: they did not have 12mm length, I bought both 10 and 14 mm, hopefully one of those lengths will work. I also wanted SST, but I searched all the stores I could think of (including ace hardware) and could not find them (except McMaster, who charges $7 or so for shipping and it takes a while).

For the grease, I found this one on Amazon. Arrives tomorrow, when I plan to re-assemble the whole thing.