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8 comments
Thanks to thread, I now have a 1/4" T25 socket in my toolkit - cheers!
Wow Canyon48 - thank you so much for taking the time to measure the bolt in such detail. You've definitely gone above and beyond the call of duty there!
No worries Steelers! Just lucky that I literally had that stem arrive through the post the day I saw your thread XD
I see what you did there...
I have this exact stem to build up my new CX bike...
The bolt is a 25mm torx.
The head diameter is 7.85mm (one would assume nominal 8mm).
The shaft is partially threaded and the full shaft length is 14.8mm.
The threaded length of the shaft is approx 9.8mm.
The diameter of the thread is 4.85mm (nominal 5mm).
The diameter of the non-threaded part of the shaft is 4.90mm (nominal 5mm).
There is a spherical washer with a 7.95mm OD and 5.30mm ID (8 and 5 nominal, respectively).
The spheric washer is 1.40mm thick and the chamfer is approx 45°.
My R5 stem has the same bolts for both the steerer clamp and faceplate. They're all T25 torx heads, that measure ~8mm diameter externally. A bigger head wouldn't sit flush.
I have a PRO stem kicking about which uses 4mm allen heads for all the bolts. The heads are the same 8mm diameter as the ones on the Fizik stem, so I'm pretty sure they would swap over without any problems. Sorry I'm not going to dismantle my bike to measure the bolt length and thread pitch.
Stem face plate bolts are M5 with a 4 mm allen head generally. M6 with a 5 mm head for the steerer clamp.
I would have fought a M4x25 socket head scres in stainless would be OK but the head of the bolt might be too big if it sits in a recess on the faceplate.