I'm looking to add threads to the 40mm chain stay holes for a kickstand. The frame did not come with them pre-threaded
The kickstand came with "m6 * 0.79" hardware as per Amazon (2nd pic)
Can one of you wizards let me know what tap size I should order? I'm struggling to make use of the chart in the first picture…
Thanks in advance!
by dealershipdetailer
5 Comments
It’s a steel frame
Meant to add that as well
M6-1.00 is the one you need.
The “0.79in” in the Amazon description must be a bizarre standards-mixing way of saying M6×20, i.e. a 20 mm long screw. Meanwhile they’re happy with “40mm” in the very same picture. God. People.
However, I’d like to see a picture of the frame to see if this plan makes sense.
I don’t condone putting kickstands on mountain bikes – especially ones that bolt into dropouts. You’re better off getting one that sandwiches your chainstays immediately behind your bottom bracket.
That being said, look at the 5th (if you have metric-sized drill bits) or the 6th column (for American bits) on the row that starts with the letters M6.
Now all you have to do is figure out the thread pitch. I can’t help you there.
First, are you sure the holes are small enough to tap and that they’re not expecting you to just put a nut on the back? I’d add a nyloc nut even if I tapped the hole since that could pull out.
I’d order it and then check the actual bolts at a hardware store or order a pitch gage at the same time.
It is most likely to be x1 but this is the kind of thing where you assume and get the x1 tap and then the bastards send you .75.
I’d bet there’s a kickstand that has threaded mounts on it. Either that or use longer bolts with nylock nuts.