V7 II - Bottom Fork Threads Possibly Stripped

[Dirk_S]

Early last spring I changed out my fork oil. My friend who helped out is a BMW guy, has owned over 30+ bikes, mostly BMWs but also a couple older English brands (definitely had a Commando at one point). Also worked for a couple major BMW dealers and shops. Anyway, when it came to disassembly and reassembly of the forks, I preferred to go by the manual, seeing that this was my first time performing such a task. My friend, after seeing the steps, questioned the necessity and shared how they always did BMW forks. So, we went soft hybrid, filling in the steps not clearly outlined in the manual with his empirical knowledge. When reassembling the forks, I tightened the bottom screw and found myself threading…and threading, to the point where I stopped myself and told him I might be stripping the threads out.

I haven’t noticed any bottoming out or leaking thus far—and that’s even with the sidecar on—but when I go to service the forks again, I was wondering if I could just do a thread repair/ Helicoil job on the fork, or if there’s some mechanism or purpose that I’m not taking into consideration?

[Antietam Classic Cycle]

Most likely the damper rod/"plunger" (as Guzzi calls it) inside is spinning as you try to tighten the bolt and nothing is actually stripped.

[sib]

Most likely the damper rod/"plunger" (as Guzzi calls it) inside is spinning as you try to tighten the bolt and nothing is actually stripped.

I agree.  When I changed my V7II's fork internals for Matris cartridges, I couldn't get the original damper rods out, the screws just kept spinning.  It was a great excuse for me to get an impact driver, which did the trick.

[Dirk_S]

Most likely the damper rod/"plunger" (as Guzzi calls it) inside is spinning as you try to tighten the bolt and nothing is actually stripped.

Is this pretty common with forks, and is there an easy tutorial for making sure I tighten them or loosen them up properly the next time?

[Antietam Classic Cycle]

Is this pretty common with forks, and is there an easy tutorial for making sure I tighten them or loosen them up properly the next time?

In my experience, yes. I don't know of a tutorial, but there's bound to be something on youtube.

[Off @ 90]

Yes this is common . Try tightening with forks fully assembled  spring, spacer and end cap installed.This puts some compression on damper rod piston and may with luck get the bolt torqued up . There is an internal hex on top of piston 22mm from memory that  you can use to hold rod while tightening but need long extensions to get down there. Quite important to get these torqued up properly as your forks could fall out if both bolts unscrew right out.

[Huzo]

Next time you have the damper rod out, have a look at the “head” end.
It will likely have a female hexagonal place where you can use an extended Allen key, or a hole where a tapered rod can insert.
Either of this type of solution, will allow you you poke the rod down the fork tube to hold the damper rod still, while you nip up the bolt.

[Dirk_S]

Appreciate these responses greatly. Makes me much less worried going into it again. Might even redo it next spring for good measure (so far, no leak or loosening)

[John A]

Some have a pin, 3 or so mm in diameter in the fork, parallel with the ground, extending maybe 5mm into the cavity that the bottom slug sits in. There is a corresponding groove in the bottom of the slug so it just sits on that pin which keeps it from turning. I don’t know if your forks have that but they can be troublesome if I don’t get the groove to index on the pin early in the assembly. You’d think it would just go into place but the slug must get cocked or something.

[Huzo]

the slug must get cocked

Oh dear….

[John A]

Oh dear….