Ok, photos have been uploaded here; http://www.sowen.com/button/index.html
The coke bottle top isn’t a replacement button… just there for size reference
Well, anyway, I was unable to find my PTFE tape, however, as you’ll see from the photos, there isn’t much thread sticking out to get the tape on. (The pictures are with the shaft sticking out - when it’s in, it is well below the level of the surrounding nut). So I just put it on dry.
I got the button on and adjusted it to the right level, then did up the grub screw nice and tight. To check if it was tight enough, I tried undoing it, and discovered 2 things;
My shaft is slightly bent (or possibly one of the buttons)
The left hand button has no grub screw!
I seem to remember putting the allen key tool in there a long time ago and thinking that the grub screw must be very deep in there, but it appears to have been grub screwless for months. Yet this one has never come undone or been lost!
Anyway, both buttons are the plastic type, so I’m not sure how long they’ll last this time. I have got a pair of new metal ones being shipped over from Switzerland, so hopefully if I do lose another one then the metal ones will last longer.
Threads cut in plastic tend to deform the plastic. The plastic “shrinks” around the tap. Plastic threads therefore tend to bind by themselves. You shouldn’t need the tape to help the threads bind against the metal shaft unless the threads have been expanded by repeated insertion and removal.
As I said, the left one should be tightening itself as you use it. It’s the right one that unscrews itslef based on the right-hand thread. a left-hand thread here would work, but would be more expensive to make.
Well, at least you didn’t say “hahahahahah - that’s going in my sig”
Ahollow - Yeah, I can see why the left button should be self tightening, but as the shaft is free to rotate, I don’t think it should make much difference. Still, with one well secured button on the right, and an unsecured one on the left, we’ll see what happens in the next couple of weeks…
Spence, if you’re missing a grub screw, aren’t they the same as DMR pedal pins? I’m sure I had a spare one hanging around for some reason, and I can’t think of any other reason I’d buy grub screws.
I’ve not got any DMR pedals I can check against, but as the left button appears to have been lacking a grub screw for a few months, I don’t think it’s going to be a problem. Or… by the time I know it is a problem, I’ve lost the button anyway! Either way, I’ve got a new pair of buttons on their way.
Semach, I hate to tell you, but I’ve never had that problem, with either the bike or the uni Schlumpfs. It sounds as though you may not have tightened the grub screw grub screw grub screw enough (I want Harper to speak that as he reads).
The best solution is a button made of aluminum, which would bind a bit nicer on the axle threads than the current plastic ones.
The tape over the hole is a good safety measure, although it’s still possible for the button to unscrew itself even if the grub screw grub screw grub screw is still inside.
One more thought: if you put some blue (mild) loctite or other threadlocker on ONE button, you may still be able to get it off by removing the opposite, and threading 2 small nuts onto the thin axle actuator, thus giving something to resist the twist when you unscrew the loctitied one. It’s not a complete solution, but you may cut your button losses by 50%, so to speak.
