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suspension fork repair - inflation valve
i'm attempting to salvage a vintage specialized fs carbon/titanium
front fork. the problem is that the right leg no longer holds air, i.e., after inflation you remove the needle and all the air comes right back out. i've taken the leg apart and it appears that the small (1.5cm length x 0.5cm diameter) rubber valve that the needle passes through has been torn. this piece sits right below the removable screw on the top of the leg. i'm wondering if it is possible to get a replacement piece, scrounge a replacement out of an old basketball, repair the piece with some sort of adhesive, or if it is best to just update the fork. any advice is greatly appreciated, b. -- rec.bicycles.off-road is moderated by volunteers. To find help solving posting problems, or contact the moderators, please see http://rbor.org/ Please read the charter before posting: http://rbor.org/rbor_charter.txt |
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suspension fork repair - inflation valve
That's a really cool fork. I have one, new, waiting for the right
project bike to install. The internals are idenitical in function to the RS MAG 21, I'm pretty sure. I heard that the Specialized FS forks that used air oil were essentially MAG 21s that were assembled by some company other than rock shox. I cannot confirm this completely as I've yet to take a SPEC FS apart. I also own a Magnesium SPEC FS that is identical to the RS Mag 21 in apparently every way, from outward appearances. The air seal you talk about is called the air cap on MAG 21s (was also used on early SIDs, I hear). When removed and inspected, it is nothing more that an aluminum sleeve filled with some kind of flexible cured plug that has a tiny star washer jammed up against it. The star washer apparently keeps the cured, flexible plug from being pushed out by the use of the inflation needle. The inflation needle is inserted into the alum sleeve and through a hole in the flexible plug. Here's the trick. I have not tried this, but mean to. Drill out the star washer, and find a way to remove the pug (solvent, heat???) Be carefull not to gouge the side walls of the alum tube. Squirt some kind of silcone sealant in to replace the plug, and let it cure. The silicone sold in small tubes at automotive stores for making engine gaskets might work best. Go to a well stocked hardware store and find / order a new star washer and jam this down the tube to secure the cured plug. I'd recommend taking an intact air cap into the HW store to show them what you need. Once the star nut is installed, take a long, stought nedle and use a thimble to push the needle though the plug, far enough to poke though the hole in the center of the star washer. These air caps used to be available as replacement parts, but were getting hard to find before the SID came around. The early SIDs exhausted the easy-find, remaining supply of these air caps. Rock shox no longer produces replacement air caps. It is interesting to note that the new, factory supplied replacement air caps required the repair shop or user to poke the hole them as described for the home-remedy, above. This confirms to me that the factory seal probably not a molded part and was not much different than the proposed home remedy (liquid silicone). Tip: don't use a sports ball inflation needle to refill these air-cap equipped forks. The air hole on the side of these sports ball needles tear up the seals a little bit with every inflation. Buy a propper needle for RS or buy a shock pump that comes with one. A propper fork needle will have the hole at the tip of the needle, with rounded edges to minimize tearing. Pat Smith moparfreak wrote in message 9... (Brian) wrote in om: i'm attempting to salvage a vintage specialized fs carbon/titanium front fork. the problem is that the right leg no longer holds air, i.e., after inflation you remove the needle and all the air comes right back out. i've taken the leg apart and it appears that the small (1.5cm length x 0.5cm diameter) rubber valve that the needle passes through has been torn. this piece sits right below the removable screw on the top of the leg. i'm wondering if it is possible to get a replacement piece, scrounge a replacement out of an old basketball, repair the piece with some sort of adhesive, or if it is best to just update the fork. any advice is greatly appreciated, b. -- rec.bicycles.off-road is moderated by volunteers. To find help solving posting problems, or contact the moderators, please see http://rbor.org/ Please read the charter before posting: http://rbor.org/rbor_charter.txt If you can find a dealer for "Total Air" they offer air cartridges to retrofit many different styles of forks (rock shox, marzocchi, etc) to a fully modern dual air cartridge system with schrader valves. This might not seem like the most cost effective way, but the extra money you put into it now will save any headaches down the road (hooray for 2 year warranties!) and it will have that super-cool looking vintage unit on the front of your bike performing just as well as a brand new Sid for a fraction of the cost. -- rec.bicycles.off-road is moderated by volunteers. To find help solving posting problems, or contact the moderators, please see http://rbor.org/ Please read the charter before posting: http://rbor.org/rbor_charter.txt |
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