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I've had an 80mm 0º stem for about 6 years (it's been on a couple of bikes). As I wanted to play around with different cockpit positions I've just bought a new 80mm 10º x4 stem from CRC.
I've noticed that where as the older x4 stem has bolts that that take a 4mm hex key, the new stem's bolt need a 3mm key; it also doesn't seem to have the torque values printed by the stem bolts as the old one did.
Have the x4 stems had a redesign (or is my new stem really ancient)? I assume that the bolts would be interchangeable, just with different hex key requirements.
IIRC it was so people didn't overtighten. I thought the torque values were still given though, it's been a few years since I fitted mine...
I've got one with the 3mm bolts. The torque vales for the face plate are on the plate itself, and for the steerer clamp on the body of the stem, although mine is quite a few years old now.
Same torque values as the thread of the bolt is the same. As above with regards to the 3mm Hex key rather than a 4mm. It's quite surprising how much torque you can generate with a 4mm Hex key. Especially with an oversized plastic handled monstrosity.
Got a new one yesterday. The face bolt torques are on the plate - 4Nm and the steerer ones on the stem body, 5 Nm.
Thanks All, it looks like my stem is a slightly newer model then and yes, I've found the torque values on the faceplate.
I'm usually pretty careful tightening things up but the 3mm bolt heads do look like they'd be fairly easy to round off!
I'm usually pretty careful tightening things up but the 3mm bolt heads do look like they'd be fairly easy to round off!
Not at 4Nm they shouldn't be!
Whenever I've tightened stem bolts to the correct torque I can still twist it on the steerer.
Could someone try theirs please.
Nope, mine is perfect at 5nm.
I had a silly OTB in a forest and twisted the bars. I could not get them straight again, I had to pull the mini-tool out and loosen off the bolts. I always use a torque wrench.
Whenever I've tightened stem bolts to the correct torque I can still twist it on the steerer.
Could someone try theirs please.
Either your torque wrench isn't reading correctly or you have grease on the steerer or you're prodigiously strong. If none of those, are you sure the bolts aren't bottoming out before being fully tightened for some weird reason or similar?
If it's marginal, maybe try some carbon paste to reduce slippage, but it really shouldn't be happening. I'd check the stem/steerer interface is clean and degreased and try a different torque wrench
[i] zippykona - Member
Whenever I've tightened stem bolts to the correct torque I can still twist it on the steerer.[/i]
You have very wide bars?
Your torque wrench needs re-calibrating.
Your steerer tube surface, or corresponding surface of the stem is contaminated.
Dirty threads are causing your torque wrench to record your specc'd torque, before it's actually reached?
You stem and steerer have mismatched diameters.
Newer ones maybe 2014-2015. I got one and as above it refused to stay in place even with a Thomson bar and carbon paste. The bolts seemed to have a tendency to unwind themselves - only a little but they are so small and the torque is so low there's no leeway
I also have an older one with the bigger bolts and that has been fine