ST1100 ABS 2001 - can not remove damper rod bolt

[John Cross]

I was planning on fitting new oil seals to my forks but have hit a snag, I can not undo the damper rod bolts. The bolt just spins. A local garage tried to drill out the bolt but can not get enough pressure on the cap for the drill to bite - again due to bolt spinning. Anyone else had this problem? any suggestions?
Thanks, John

 

[dwalby]

normally if you have the fork fully assembled with spring tension applied you can break the bolt loose with an impact wrench.

 

[John OoSTerhuis]

If the socket hasn’t been rounded out, try an impact wrench like Doug said. However, if someone is at the point of trying to drill off the bolt head, I suspect the socket is damaged. Two things - try hammering in a torx bit to get solid purchase for backing it out, but first immerse the bottom of the fork slider in very hot water for a while. Then try the impact wrench. FWIW

Good luck.

Edit: in order to increase the pressure on the rod in an attempt to keep it from spinning, you might try a longer preload spacer on that fork. Thinking out loud here...

John

 

[Bmacleod]

I just recently had my forks apart and had a bit of difficulty with both forks, moreso one in particular. What helped me was not applying spring pressure, but trying to hyperextend the damper rod. The compression valve, which the bolt threads into, sits in the cartridge and the spring applies zero pressure to this. there is a spring clip below the valve however that if you pull on the damper rod, will apply a little resistance to the compression valve. The thing that helped was using an impact on the bolt to where it would start to spin, then threading it back in tight then spinning it back again. It seemed that there was likely some loctite was causing some sticking and by going back and forth, I was able to "break through" this part. It took 5 or 10 tries but finally the bolt came out. That was the stubborn one, the easier one just required pulling the damper rod to tighten the compression valve against the circlip. Note when using the impact... I am not talking about an air powered 1/2 drive impact ,but a small electric unit and you still have to be careful when threading in. The idea is just to get it back to the start to take a run at backing it out. Dont worry about tightening it. I am hoping that by not having success drilling it out, that means there is still something for the allen key to grip. Otherwise, you will have to continue to try and drill it out, which can be done, but that is another thread.

 

[dwalby]

the OP has an 1100, which I think may be slightly different than the 1300, but I can't recall for sure. the 1100 has one old style conventional fork, and one cartridge style. Does the 1300 have the same arrangement, or are they both cartridge style?? Sounds like both have damper rods in the 1300, so they're both cartridge style, is that correct??

 

[Bmacleod]

Yes, I believe that the 1100 forks are different than the 1300 forks, but according to the diagrams I looked at, the bolt still threads into a compression valve in the bottom of the damper rod on the 1100 and is still held in with a circlip identical to the 1300 cartridge style compression valve

 

[John Cross]

Thanks for all the advice. I assumed compressing the forks would help to prevent the damper rod rotating so set up a rig with a scissor jack to fully compress before "shocking" the bolt with an impact driver. It now feels as though the thread has stripped in the damper rod - turning the bolt it gets slightly tighter then loose, tighter then loose.....
I will try hyper-extension to see if this gets me anywhere.

 

[SMSW]

the OP has an 1100, which I think may be slightly different than the 1300, but I can't recall for sure. the 1100 has one old style conventional fork, and one cartridge style. Does the 1300 have the same arrangement, or are they both cartridge style?? Sounds like both have damper rods in the 1300, so they're both cartridge style, is that correct??

Both of my forks were identical when I put the Gold valves in (2010 1300). I'm not sure what you mean by cartridge type vs. damper rod, but both forks had the bolt at the bottom that threaded into the same comp. valve w/ stacked shims.

 

[dwalby]

Both of my forks were identical when I put the Gold valves in (2010 1300). I'm not sure what you mean by cartridge type vs. damper rod, but both forks had the bolt at the bottom that threaded into the same comp. valve w/ stacked shims.

yes, the bolt at the bottom is common in all forks, I was asking a different question.

Not sure if I have the terminology correct, but here goes.

On the 1100 one of the forks is old school. You pull the fork cap off and there's just a spacer and a spring sitting there that you pull out with your fingers.

The other fork is "cartridge" style, meaning that there's a central damping rod with a nut and threads on the end of it that sits inside the spring diameter. There is a "C" shaped clip that sits under the nut at the end of the damping rod that compresses the spring. The fork cap is threaded with the same threads as the end of the damping rod, and the damping rod threads into the bottom of the fork cap.

I vaguely recall hearing that on the 1300 both forks are of the "cartridge" type I described, can you confirm that?

 

[dwalby]

Thanks for all the advice. I assumed compressing the forks would help to prevent the damper rod rotating so set up a rig with a scissor jack to fully compress before "shocking" the bolt with an impact driver. It now feels as though the thread has stripped in the damper rod - turning the bolt it gets slightly tighter then loose, tighter then loose.....
I will try hyper-extension to see if this gets me anywhere.

I remember many years ago seeing a picture of a tool that you put down inside the fork upper tube to prevent the innards from rotating and causing the problem you are experiencing. But, I think that tool only worked on the old school style forks. And, since everybody used an impact wrench anyway, I never actually saw the tool in person, just in a shop manual somewhere.

In your case it sounds like you're having trouble with both of them, not just one, is that correct?? The reason I ask is if you can make up a similar tool you might be able to at least get the old school fork apart, but I don't know that it would work on the "cartridge" fork.

 

[SMSW]

I vaguely recall hearing that on the 1300 both forks are of the "cartridge" type I described, can you confirm that?

Yes, I would guess then both fork legs were of the cartridge type because they are identical. The top cap screws into the upper fork leg, a tube screws to the under side of the cap. The spacer and spring surround this tube/rod, which goes down to the rebound(?) valve and shim stack. The compression valve and shim stack sit on the bottom of the lower tube, bolted through the bottom.

RaceTech also sells a cap kit that allows external adjustment (screw on top of the cap). I believe this changes one fork to compression and the other to rebound damping, but I'm not sure. IIRC, it cost another buck and a half for the external adjustment kit.

 

[Bmacleod]

Thanks for all the advice. I assumed compressing the forks would help to prevent the damper rod rotating so set up a rig with a scissor jack to fully compress before "shocking" the bolt with an impact driver. It now feels as though the thread has stripped in the damper rod - turning the bolt it gets slightly tighter then loose, tighter then loose.....
I will try hyper-extension to see if this gets me anywhere.

The piece that the bolt screws into fits into the damper rod/cartridge with only an o-ring and can spin. This could be the feeling you are getting when it feels stripped. I cant imagine you have stripped it as long as you have not over-tightened it. Try applying heat to the bolt to loosen up any loc-tite that may be on the threads. You can also try tightening the bolt to see if you can snug it up, where you can then drill it out. Also, try removing any external drain valves or anti-dive valves and see if you are lucky enough to access one of the holes in the damper rod/cartridge that you could insert a small screwdriver into to hold the damper rod