Correct headset tightness
I've been doing a few bits on my bikes and one of the things I seem to struggle with is getting the headset tightness right.
I have learned how it should be tightened etc, but the process of tightening it still seems a bit of a dark art to me.
I have two bikes with disc brakes (one hydraulic and one cable). I have worked on both headsets. When doing them back up, I get the tightness right in the sense of there are no creaking noises and the steering moves freely. However, there always seems to be a bit of movement when rocking the bike forwards and backwards with the front brake on. Is this caused by the fact that I have disc brake and there is a bit of flex in the wheel etc?
The movement isn't really a knock, it's just a movement that happens when wobbling the bike with the front brake on. I have tried tightening the headsets more (beyond the little bit you are supposed to do with the top nut), but this movement never seems to go away.
Is this normal? Should I just be making the headset bolt tighter?
One of my bikes had the bolt done up ridiculously tight by the bike shop and it made quite a creaking noise. Slackening this off has helped, but I'm paranoid that I haven't now got the thing tight enough.
Thanks all.
I have learned how it should be tightened etc, but the process of tightening it still seems a bit of a dark art to me.
I have two bikes with disc brakes (one hydraulic and one cable). I have worked on both headsets. When doing them back up, I get the tightness right in the sense of there are no creaking noises and the steering moves freely. However, there always seems to be a bit of movement when rocking the bike forwards and backwards with the front brake on. Is this caused by the fact that I have disc brake and there is a bit of flex in the wheel etc?
The movement isn't really a knock, it's just a movement that happens when wobbling the bike with the front brake on. I have tried tightening the headsets more (beyond the little bit you are supposed to do with the top nut), but this movement never seems to go away.
Is this normal? Should I just be making the headset bolt tighter?
One of my bikes had the bolt done up ridiculously tight by the bike shop and it made quite a creaking noise. Slackening this off has helped, but I'm paranoid that I haven't now got the thing tight enough.
Thanks all.
0
Posts
No rattling > ok, tight enough.
It's no rocket science....
I thought it was literally finger tight using the small bit of an Allen key as the turning point. Guess I need to be tighter.
Bikes do rattle when I drop the headsets.
5nm is a meaningless figure, as tension will depend on the bike, the headset and probably other external factors as well. As others have said, just nip it up by hand until you cannot feel any movement. A good way of eliminating brake movement from the equation is to rock the bike with the front brake on, but with the bars turned 90deg.
Thanks. Will nip it up by hand. Was originally concerned about going too tight to get rid of all movement.
Thanks for the handlebar angle tip.
You need 3-5 mm. If the gap is too small you can tighten all you want but still cannot preload it enough.
Try a spacer above the steerer to see if that is the problem.
Thanks.
These are pre built manufacturer bikes so I'm guessing they are ok. I just need to be tightening them more.
Just for the avoidance of doubt, you are loosening the 2 pinch bolts before tightening the top cap?
TBH if you are squeezing the brakes hard then the clamping action of the calipers on the pads and disk shouldn't allow any movement especially at the forces of moving bike back and forward by hand and not with a 80kgs rider going down a 14% hill and applying brakes
I've had at least a 5mm spacer between the stem and topcap, to ensure the spacer sits at least 3mm higher than the steerer, so the topcap can preload properly, while the stem steerer bolts are loose.
Recently moved another 15mm of spacers above stem, so the stem isn't sitting around the bung, but it's a bit odd they have a bung inside an alloy steerer.
Topcap tightened to ~4nM.
Then stem steerer bolts tightened to 5nM.
2020 Voodoo Marasa
2017 Cube Attain GTC Pro Disc 2016
2016 Voodoo Wazoo
That sounds about right from my experience as well.
As mentioned earlier, it's wrong to specify any particular torque number for the top cap - it simply doesn't work like that.
Indeed the first bike I owned with a threadless headset had a flimsy plastic top-cap with an alarming yellow warning sticker on it. Clearly designed to fail and prevent over-tightening.
Totally correct.
You can guess or say what torque it is on your bike but it is misleading and bad advice to anyone learning to adjust a headset to even mention torque.
In fact the only reason to put a torque wrench on the top bolt is if you've lost an allen key and it's the only thing you have lying around.
OP, do not listen to torque advice, it's bad advice.
The torque numbers quoted are a useful guide. I don’t know of any headset that will be damaged at four or five Nm. I tend to go on feel if I’m nowhere near a torque wrench. Tighten with an Allen key until all play is gone and the bars turn freely. If I have a torque wrench I’ll aim for 4 or 5 Nm. Why not utilise a proper bit of kit if you have one available? I’ve rarely if ever had to go to more than 5 Nm of torque to get the headset tightened acceptably.
It's not a 'useful guide' - it's completely irrelevant. There is absolutely no requirement to use a torque wrench on a top cap - so it is not a 'proper bit of kit' in this context, because a torque value has no meaning and no practical use. This conversation is so utterly stupid, I actually can't believe we're having it...
Because if 2Nm is enough to centre / settle the components and remove the play, what do you hope to gain by tightening it further to 5Nm? It's the pinch bolts in the stem that hold everything together; once they are tightened up - use your torque wrench here by all means - you can completely remove the top cap and bolt if the fancy takes you.
The stem bolts hold the applied pre load tension that’s true. But I’ve got a bike with a carbon steerer and bars and that actually has 6Nm as the marked torque for the headset preload and the stem bolt torque. I use that as a guide.
There is no need to use a torque wrench to adjust the headset its tight enough when its tight enough and too tight when its too tight. The torque measurement is incidental in that theyre never specified since the correct torque is somewhere in a range.
torque measurements are a red herring here.
You have bars and stem marked with 6nm? Thats usually the stem and clamp bolt torque to stop crushing of tubes not a headset instruction.
Don't give out advice please. You just said "If I have a torque wrench I’ll aim for 4 or 5 Nm" ...you've just admitted you will aim to do it up to a torque range with a torque wrench. It might "work" for you but you'll not find any bike mechanic in the country stupid enough to do it that way because it's quite simply a dumb approach to it.
Have you ever seen a headset manual telling you to do it this way? No. You haven't.
Anyway, the OP has had good advice now so it doesn't matter.
(I actually am not sure if you're just slyly winding people up, it's that cleverly stupid what you're saying.)
I too have a bike with a full carbon fork, so I'm off to have a look at the top-cap. I remember there was a torque figure mentioned for tightening the bung into the steerer, but the top-cap I remember doing by feel / trial and error. And having to chop a bit more off the steerer to achieve the necessary clearance...
Putting my pedant hat on...
Read the quote exert from my earlier post.
It does not instruct OP to tighten topcap to ~4nM, it says "tightened to ~4nM," as in that is what I did. It was not done with a toque wrench, hence the "~" sign, unlike tightening the stem bolts to 5nM with a torque wrench.
Having experienced mysterious spacer slippage over time, which I ultimately discovered was due to bung bolt being loose, I perhaps "finger-tightened" the topcap a little more than was necessary. I was rather slow in picking up this bung bolt issue, over the course of ~12 months I had added another 5mm spacer to the stack!
Throwing my pedant hat back under the mothballs.;)
2020 Voodoo Marasa
2017 Cube Attain GTC Pro Disc 2016
2016 Voodoo Wazoo
As I’ve just posted. I have a bike where the headset preload and stem bolt torque are specified. It says 6Nm but unless the bearings are brand new that does lead to a bit of roughness or oversight feeling so I use 5 as a better guide.
post a pic..or give us a link to the bike in question..