lukebin Posted October 3, 2007 Share Posted October 3, 2007 Hey everyone, I was helping my friend rebuild his front forks. We were putting in new Racetech springs and a change of fork oil. Well when reassembling the damping rod/piston back into the fork base on one fork the fork bolt tightened up nicely. When we went to tighten the fork bolt on the other fork base with piston it would not tighten completely, the dampening piston seemed to be slipping inside and the bolt would not tighten. So the manual recommended reassembling the rest of the fork and then trying it again, presummable the spring would help to hold everything in place. This still did not work and the bolt still does completely tighten and some folk oil leaks out the bottom of the fork. We did find that when the fork was assembled and I pulled on the fork TUBE it help and there was some extra resisitance for the bolt but not enough to fully tighten it. My only other thought at this time is to keep the fork inverted still together and get some of the oil out of the end of the fork where the bolt is and maybe it will bind better when "dryer" and also try pulling on the tube again. All I can think of is that the internals of the piston where the bolts mounts to needs to be held from turning by "friction" to the piston to get the bolt to tighten properly and this particular piston "end" maybe slightly warn. Any thoughts would be appreciated. Christian Link to comment Share on other sites More sharing options...
lukebin Posted October 3, 2007 Author Share Posted October 3, 2007 Well I call Racetech and they said that the best I could do was to clean off the bolt as best as possible to reduce that friction and then pull like hell on the fork tube to put pressure of the bottom of the dampener to hold the value tight so that the bolt can seat properly. It seems all to whacky to me ... Christian Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted October 3, 2007 Share Posted October 3, 2007 Problem is, you're threading into a blind hole with nothing to hold the female threads stationary, they will spin if there's enough friction before clamping force takes over and binds the assembly, helping you to tighten the bolt the last bit. I seem to recall that using an impact wrench helps. Spins the bolt faster and the jarring motion of the impact helps it thread home. Make sure it's on it's lowest setting though. Link to comment Share on other sites More sharing options...
Guest VFRJohn Posted October 9, 2007 Share Posted October 9, 2007 Suggestion: Try whacking the wrench with something hard - like a piece of wood or small hammer. The inertia of the damper tube might provide enough resistance for the bolt to tighten. Sort of a poor man's impact wrench! Oh - another possibility: Try an impact screw driver - the kind where you apply some twisting force (um, aka "torque") with one hand, and hit the end of the tool with a hammer. It has a ramp mechanism inside that converts the hammer blow into torque. I bought one at Sears a few decades ago. Usually used to loosen screws in aluminum casings. Link to comment Share on other sites More sharing options...
SEBSPEED Posted October 9, 2007 Share Posted October 9, 2007 Suggestion: Try whacking the wrench with something hard - like a piece of wood or small hammer. The inertia of the damper tube might provide enough resistance for the bolt to tighten. Sort of a poor man's impact wrench!Oh - another possibility: Try an impact screw driver - the kind where you apply some twisting force (um, aka "torque") with one hand, and hit the end of the tool with a hammer. It has a ramp mechanism inside that converts the hammer blow into torque. I bought one at Sears a few decades ago. Usually used to loosen screws in aluminum casings. An impact gun is what all the shops use; if you have a pneumatic one, regulate your psi down a bit so you don't strip the threads. Most guys I've seen use the electric cordless type guns. I'm getting one soon! :thumbsup: Link to comment Share on other sites More sharing options...
Member Contributer swas Posted October 9, 2007 Member Contributer Share Posted October 9, 2007 "An impact gun is what all the shops use" :thumbsup: That's what I have seen done, even on forks which have a nut or something to hold internally. The speed seems to overcome lack of friction on the inner. Link to comment Share on other sites More sharing options...
R_Cote Posted November 6, 2007 Share Posted November 6, 2007 This may be a little late but I do have a fix for that annoying spinning base valve when assembling and disassemling your forks. A picture is worth a thousand. All I did was drill and tap for a set screw. This keeps the base valve from spinning within the cartridge. Hopefully the entire cartridge won't spin. But, the cartridge can be held from spinning if need be. Should never be a problem again. IMG_0926.JPG Drilled cartridge.JPG Spinning Cartridge fix. Do these pictures help? Link to comment Share on other sites More sharing options...
SEBSPEED Posted November 6, 2007 Share Posted November 6, 2007 I can't help but wonder where the preload was set on the spring(fork assembled) while trying to tighten that bolt? I recently helped Poncho do his forks, and thought we would have the above problem, but didn't. I think it's because we dialed in preload(while tightening the fork cap back to the damping rod, w/ the 2 14mm wrenches, you have to spin the cap up, setting preload higher), and didn't dial it back out before screwing the cap back into the tube. Maybe. I dunno. I did get that cordless impact gun though. $70 at Home Depot, works with the same battery as my other cordless Ryobi tools. B) Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted November 6, 2007 Member Contributer Share Posted November 6, 2007 This may be a little late but I do have a fix for that annoying spinning base valve when assembling and disassemling your forks. A picture is worth a thousand. All I did was drill and tap for a set screw. This keeps the base valve from spinning within the cartridge. Hopefully the entire cartridge won't spin. But, the cartridge can be held from spinning if need be. Should never be a problem again.Do these pictures help? Like it! :thumbsup: Can't think of a reason why you'd want the cartridge tube to be able to spin (which this fix would prevent), but I'm no Showa fork expert. Unfortunately, the problem is usually on disassembly (and usually the first time the forks are disassembled), so this fix is a little too late for most people, but potentially great if you go into your forks regularly. Thanks for the idea--and the pics! Ciao, Link to comment Share on other sites More sharing options...
R_Cote Posted November 6, 2007 Share Posted November 6, 2007 Well. Actually I found the problem to be was there wasn't enough friction between the bottom of the base valve and the circlip that keeps it from pulling out of the bottom of the cartridge. Even reassembling with the spring in and using the impact wrench was still not enough. What I had to do was pull up on the cartridge rod very hard. This starts to compress the top out spring. This was the only way I could stop the base valve from spinning. Now I've only taken them apart once and I did not use locktight on the bolt when I reassembled. I know with this mod there is no way the base valve can rotate inside the cartridge. Here is a picture of how I put constant pressure on the cartridge rod. I stacked spacers together to take up the slack. Then tightened the nut down. Preloaded rebound.JPG Link to comment Share on other sites More sharing options...
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