Sunday, 12 January 2025

listening to your inner voice

I decided that I wanted to change the (rather antique style) grips on my SR500 for something more comfortable. 

I'm pretty happy with them but unlike the older styles, the ends are "uncovered" on modern grips. This left me the task of attaching end covers for aesthetic and functional reasons. I ended up selecting these:


as (before I'd taken the grips off) I figured they'd be suitable no matter what I found (empty hollow bar end or filled in with something. As it turns out the Yamaha bars had solid steel rod inserted into the bar to assist with damping vibrations. So I had to drill and tap a thread into this.

This task was done by:

  1. carefully identifying the center and then marking that with a center punch
  2. drilling a small pilot hole (that was straight and con-centric to the bars)
  3. successively drilling this out to the final diameter needed for the thread cutting tool
  4. cutting that thread (there's a technique) 
  5. shortening the supplied bolt
  6. screwing it in and using light grade thread locker on that 


Left hand done, I moved over to the right where I met with problems on step 4


Because of an additional complication on the RHS, you can't imagine how much I feared this outcome and had taken every possible precaution against it by 
  • turning gently (two fingers)
  • only turning till it bound
  • back off at least one, sometimes two turns to feel for the 'break' of the cutting tool swarf 
  • backing all the way out to double check the measurements of drill depth 
  • knowing how far I'd been able to turn the cutting tool into the newly cut thread...

Of course now I haven't fucking got a cover on that side because when you break these off in there, there's just no drilling it out ...


On the place it broke, I'd felt that while the screws had enough thread I did not test that on the many occasions I'd backed out. I should have been doing this to be clear exactly how many turns of thread the cover mounting screw had (and it only needs a few right!!).

Had I done that I may well have saved this issue, had a good looking bar end on the right and maybe just more loctite on that one ... FCK

This is as much a warning to  others as an exercise in accident analysis and self punishment

FCK!

2 comments:

Stephen Mundane said...

Arghh -- that sucks! Hope that you get it sorted because those grips and bar end(s) look very smart. Looking forward to an update.

obakesan said...

Hey, thanks for the kind comment. In conversation with a mate he's suggested I can probably weld a nut on in that space and have just enough to screw the cap with. I'll need to use thread locker for sure on that.
You can't over-estimate how much I'm still kicking myself for this because I now see that so many times I had it all removed and *>should<* have just tried my bolt in the hole rather than just measuring it. But I clearly got carried away and lost sight of "what I'm there for" ... to get just enough thread to hold it. Now I'll have to go to heaps more work to get "just enough thread to hold it" with welding on a ground down nut.
FCK