bolt size help
- Thread starter dirtydozen
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eastsidebikes
Retro Guru
Bolts are best specified by outside diameter of thread x thread pitch. Thread pitch for metric bolts is how many mm between threads.
So M6x1.25 is 6mm outer diameter with 1.25mm between the threads.
Thread pitch is possible to measure by counting the threads in say, 25mm of bolt then dividing 25mm/number of threads. Or you can get a thread gauge which you mesh with the threads, like this
Like the others say, Alu bolts in your stem aren't a good idea other than possibly your top cap. Ti is miles better but watch out for corrosion - Alu and Ti galvanicaly corrode really badly together
So M6x1.25 is 6mm outer diameter with 1.25mm between the threads.
Thread pitch is possible to measure by counting the threads in say, 25mm of bolt then dividing 25mm/number of threads. Or you can get a thread gauge which you mesh with the threads, like this
Like the others say, Alu bolts in your stem aren't a good idea other than possibly your top cap. Ti is miles better but watch out for corrosion - Alu and Ti galvanicaly corrode really badly together
so...
NO ALLOY BOLTS IN A STEM!
Top cap bolt is fine in alloy though, as are the cable clamp bolts on your mechs (M5), band clamp bolt on front mech (M5), pivot bolt on rear mech (eg SRP), shifter mount clamp bolts (generally M6).
If your stem bolts are the same size as your disc calipers bolts, then they are M6.
NO ALLOY BOLTS IN A STEM!
Top cap bolt is fine in alloy though, as are the cable clamp bolts on your mechs (M5), band clamp bolt on front mech (M5), pivot bolt on rear mech (eg SRP), shifter mount clamp bolts (generally M6).
If your stem bolts are the same size as your disc calipers bolts, then they are M6.
dirtydozen
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So I have to stick with boring coloured bolts 
eastsidebikes
Retro Guru
Or colour them in with a gold pen
dirtydozen
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Pmsl where do I get this to ones then lol yes iam a tart
eastsidebikes":2u2bmuyk said:
I thought it was the depth of the threa rather than the distance between. So for internal threads you can measure the internal hole (including the thread) and then take an educated guess, so if your hole is metric and 8.75mm wide, its going to be an M10x1.25 thread. Useful if you can get a verier caliper or a hole guage in, but not a thread guage. Just measure it accurately.
