Front suspension pinch bolt issue

Hi all

Picked up some useful info from here that has assisted with the servicing of my new to me SW. It is obvious that it had been neglected by the previous owners.

I am working through everything and whilst doing this I noticed under the faring one of the pinch bolts (top right one) securing the front suspension top was half hanging out. Removed faring and removed the bolt as it was simply not just unscrewing. The thread was stripped.

Ordered 4 new bolts and proceeded to fit and replace all 4. However the top right one just strips the thread of the new bolt. Will the thread need re-tapping? I read somewhere that there is a location slot on the suspension but can't see one near the bolt entry. The other 3 bolts replaced easily.

Any help and suggestions appreciated.

Thanks

David

Opening the door on the Wayback Machine (aka the Search window) I found a previous discussion regarding front end work.

Hopefully your stripped bolt isn’t the top one. That’s the bolt which fits in the fork tube groove. If it’s the lower bolt hole which is stripped then you may be able to rethread to a larger size or use a longer thru bolt & nut so that the fork tube is securely pinched. Below is a link and a photo which might help.

The above said, the “official” advise is to replace that stripped steering stem.

https://www.silverwing600.com/viewimage?u=https%3A%2F%2Fi.servimg.com%2Fu%2Ff37%2F13%2F47%2F36%2F26%2Ffile0114.jpg

Cosmic_Jumper wrote:

Opening the door on the Wayback Machine (aka the Search window) I found a previous discussion regarding front end work.

Hopefully your stripped bolt isn’t the top one. That’s the bolt which fits in the fork tube groove. If it’s the lower bolt hole which is stripped then you may be able to rethread to a larger size or use a longer thru bolt & nut so that the fork tube is securely pinched. Below is a link and a photo which might help.

The above said, the “official” advise is to replace that stripped steering stem.

Thanks for your reply. Unfortunately it is the top bolt.

The tube groove, I presume that the bottom bolt slots in to this, is that correct?

Is there a reason the top can not be re-threaded?

David

DavidL wrote:

Thanks for your reply. Unfortunately it is the top bolt.
The tube groove, I presume that the bottom bolt slots in to this, is that correct?
Is there a reason the top can not be re-threaded?
David

IIRC it’s the top bolt which fits the fork tube groove. I assume that either of those bolt holes can be re-threaded. But it might get a bit knotty finding a new bolt which also fits that fork tube groove properly.

But perhaps others, with more recent fork tube experience, will chime in and show me to be wrong. It won’t be the first time —nor the last (I’m sure).

Cosmic_Jumper wrote:

DavidL wrote:

Thanks for your reply. Unfortunately it is the top bolt.
The tube groove, I presume that the bottom bolt slots in to this, is that correct?
Is there a reason the top can not be re-threaded?
David

IIRC it’s the top bolt which fits the fork tube groove. I assume that either of those bolt holes can be re-threaded. But it might get a bit knotty finding a new bolt which also fits that fork tube groove properly.

But perhaps others, with more recent fork tube experience, will chime in and show me to be wrong. It won’t be the first time —nor the last (I’m sure).

Thanks

I did check this groove earlier, through the slot gap it appeared to be between where the bolts go?? (I may be wrong). So would mean the top of the shock would sink below the top of the clamp if it is the top bolt. Or pop out of top if the bottom bolt. The left side, the top is more of less flush with the top. Hope this makes sense.

Hopefully somebody can confirm which bolt sits in the groove.

From memory the fork tube sits proud of the top of the stem by about 3-4mm.

Without thinking too much about the technicalities, could you find a longer bolt of the same diameter which would allow you to use a nut on the other end to create the 'pinch'?

Loosemarbles wrote:

From memory the fork tube sits proud of the top of the stem by about 3-4mm.

Without thinking too much about the technicalities, could you find a longer bolt of the same diameter which would allow you to use a nut on the other end to create the 'pinch'?

I had thought of a nut at the back but the hole is not all the way through and slanted at the back so no flat surface and a very long bolt would be required.

Tomorrow I will check the slot/groove and options of where the bolts fit and positioning of the shock. Although I may need to jack up the frame to lower the front wheel and I don't have a jack available at present.

Can't find any images to confirm if the top or bottom bolt sits in the groove so if anybody can confirm this would be appreciated.

"Can't find any images to confirm if the top or bottom bolt sits in the groove so if anybody can confirm this would be appreciated."

The upper bolt is clearly the one that catches the groove, is placed inward towards the tube, the bolts are not aligned with each other, those bolts require a lot of torque (51 ft/lbs or 69 N/m) to clamp those forks correctly and are a structural part of fork assy., no easy fixes here. A proper thread fix or installing a Heli coil may be able to handle the fork stress, is a heavy scooter, a used salvage yard part may be the best/safe solution. Those bolts should be torqued evenly, with several steps of increasing torque values to final number, torquing one bolt alone to max torque will overstress the threads.

I would not recommend drilling thru part, it may cause a stress/failure point, there's a lot of twisting forces on that single steering stem.

zrx212 wrote:

The upper bolt is clearly the one that catches the groove, is placed inward towards the tube, the bolts are not aligned with each other, those bolts require a lot of torque (51 ft/lbs or 69 N/m) to clamp those forks correctly and are a structural part of fork assy., no easy fixes here. A proper thread fix or installing a Heli coil may be able to handle the fork stress, is a heavy scooter, a used salvage yard part may be the best/safe solution. Those bolts should be torqued evenly, with several steps of increasing torque values to final number, torquing one bolt alone to max torque will overstress the threads.

I would not recommend drilling thru part, it may cause a stress/failure point, there's a lot of twisting forces on that single steering stem.  

There ya go! Take that as gospel.

Yes, the second and last photos are correct, a portion of fork tube normally protrudes above fork clamping area, only way it will align with groove an allow a bolt to be installed/threaded correctly, obviously it was improperly installed before , maybe your threads are fine Good thing you noticed before , make sure you torque/tighten evenly, very important.

zrx212 wrote:

Yes, the second and last photos are correct, a portion of fork tube normally protrudes above fork clamping area, only way it will align with groove an allow a bolt to be installed/threaded correctly, obviously it was improperly installed before , maybe your threads are fine Good thing you noticed before , make sure you torque/tighten evenly, very important.

Thanks, yes threads seem ok, ran a tap through to confirm.

I always torque to spec but good tip re tightening evenly and gradual between each bolt.  

Whilst they are off I am going to have seals replaced.

Good to hear is all sorted, like the old adage " A picture is worth a thousand words " when you are trying to convey information

If you need a steering stem i have a couple of them

Check the head bearings while the forks are off, replace with tapered rollers