1 1/8" threaded headset quill / expander bolt torque..

[wafter]

Does anyone have any torque recommendations for the expander bolt on a 1 1/8" threaded headset please?

I've just aligned the bars on my pub bike and made an effort to tighten the expander bolt to about where it was previously; checking this with a torque wrench suggests around 5N.m. I can't get the bars to move relative to the wheel when applying a reasonable amount of force and gripping the wheel between my feet and knees..

However.. this Park Tool page suggests (depending on source) anything between around 16 and 29N.m (144-260 in.lb). Tbh applying three times the torque I have makes me feel uneasy that I'm going to knacker something, while six times seem ridiculously excessive. That said, of course don't want the headset becoming loose while riding...

Any insight from those more expeerienced with threaded headsets wouol be much appreciated, please

 

[DCBassman]

Does anyone have any torque recommendations for the exapander bolt on a 1 1/8" threaded headset please?

I've just aligned the bars on my pub bike and made an effort to tighten the expander bolt to about where it was previously; checking this with a torque wrench suggests around 5N.m. I can't get the bars to move relative to the wheel when applying a reasonable amount of force and gripping the wheel between my feet and knees..

However.. this Park Tool page suggests (depending on source) anything between around 16 and 29N.m (144-260 in.lb). Tbh applying three times the torque I have makes me feel uneasy that I'm going to knacker something, while six times seem ridiculously excessive. That said, of course don't want the headset becoming loose while riding...

Any insight from those more expeerienced with threaded headsets wouol be much appreciated, please

I still use a bike with this size and type of headset.
If you've got it where you're happy it won't move, I'd leave it there. Most of these, in my experience, are all steel, so can probably handle more torque, but if it's OK, it's OK.

 

[wafter]

I still use a bike with this size and type of headset.
If you've got it where you're happy it won't move, I'd leave it there. Most of these, in my experience, are all steel, so can probably handle more torque, but if it's OK, it's OK.

Thanks - I think the steerer tube is steel so that's reassuring.

I like numbers so I'll stick to the 5N.m now and see how it goes as it appears pretty sturdy (stays put under a lot more load than I'd expect it to encounter during normal use); if I encounter any issues I'll maybe wind it up a little more

 

[Smokin Joe]

I never knew anybody who used a torque wrench on a bike before carbon fibre came along and made us all paranoid about over tightening bolts. I must have fitted scores of quill stems just on feel and never had a problem.

 

[wafter]

I never knew anybody who used a torque wrench on a bike before carbon fibre came along and made us all paranoid about over tightening bolts. I must have fitted scores of quill stems just on feel and never had a problem.

I'm usually the same, however given how potentially critical it is and my lack of experience with this particular setup I figured it never hurts to ask those more educated

 

[rogerzilla]

Some Cinelli stems have aluminium expander bolts. These scare me. I wouldn't ride one even if I knew the correct torque setting.

Steel ones are usually just done up pretty tight. Be a little more wary if the steerer tube is weak (aluminium?) or it's the expander cone type.

 

[mickle]

Grease the surface between the quill and the wedge. Also the bolt / wedge threads and under the head of the expander bolt. Also inside the steerer prior to inserting the stem.

 

[wafter]

Some Cinelli stems have aluminium expander bolts. These scare me. I wouldn't ride one even if I knew the correct torque setting.

Steel ones are usually just done up pretty tight. Be a little more wary if the steerer tube is weak (aluminium?) or it's the expander cone type.

Thanks

The ally bolts sound like an un-necessary safety compromise for the sake of saving what must only be a few grams

Grease the surface between the quill and the wedge. Also the bolt / wedge threads and under the head of the expander bolt. Also inside the steerer prior to inserting the stem.

Cheers - I've not had the whole assy out but will put that on my to-do list. Any recommendation for type of grease please? I'm guessing something with anti-seize properties..


I've now ridden the bike since I made the adjustments; and (despite various other problems elsewhere) at least the steerer assy didn't come to bits so it looks like the 5Nm is fine. Thanks again for the replies

 

[Ian H]

The old advice was that you should be able to move the bars with some force. Thus they'll slip in the event of a crash, rather than bending or breaking. You will never exert any significant turning force when riding. It's a bit more complicated with Ahead stems, where they have to hold the bearings in adjustment as well.

 

[wafter]

The old advice was that you should be able to move the bars with some force. Thus they'll slip in the event of a crash, rather than bending or breaking. You will never exert any significant turning force when riding. It's a bit more complicated with Ahead stems, where they have to hold the bearings in adjustment as well.

Thanks - I read that too but it's all a bit nebulous and subjective isn't it? Tight enough to stop it all going wobbly under normal use, wobbly enough to prevent damage in a crash.. by the same token I guess trying to assign a single torque value is similarly unhelpful given the range of component sizes, designs, materials and lubrication that are out there...

 

[Ian H]

Nothing nebulous, just a bit of trial & error the first time you do it. The wedge, once tightened, requires a tap on the loosened bolt to release it.

 

[C R]

Thanks - I read that too but it's all a bit nebulous and subjective isn't it? Tight enough to stop it all going wobbly under normal use, wobbly enough to prevent damage in a crash.. by the same token I guess trying to assign a single torque value is similarly unhelpful given the range of component sizes, designs, materials and lubrication that are out there...

In a threaded headset the expander bolt only holds the handle bar in position. The headset itself is adjusted and held in place with the locknut at the top of the head tube. Even if the expander bolt slips, if the locknut is set properly, the headset itself will not be affected.

 

[mickle]

Also. Always obey the 'minimum insertion' line. Raising the stem above this height increases the leverage on the lower part of the quill and lifts the expander into the threaded (and therefore thinner) zone of the fork steerer tube. A recipe for disaster; when the tube wall fails the stem lets go.

 

[wafter]

Nothing nebulous, just a bit of trial & error the first time you do it. The wedge, once tightened, requires a tap on the loosened bolt to release it.

Ta - I guess it's just a case of getting a feel for it; however given my lack of experience it's always nice to have some numbers to fall back on if possible. Certainly seem OK at the current tightness so will use this torque from now on unless I'm given reason to change.

In a threaded headset the expander bolt only holds the handle bar in position. The headset itself is adjusted and held in place with the locknut at the top of the head tube. Even if the expander bolt slips, if the locknut is set properly, the headset itself will not be affected.

Thanks; I realise that although I think the bars coming loose relative to the wheel is certainly enough to cause disaster in its own right

Also. Always obey the 'minimum insertion' line. Raising the stem above this height increases the leverage on the lower part of the quill and lifts the expander into the threaded (and therefore thinner) zone of the fork steerer tube. A recipe for disaster; when the tube wall fails the stem lets go.

Cheers - the bike has a very "relaxed" geometry so I've actually gone the other way and dropped the bars just to see how it rides, so no danger of over-extension, although I appreciate the thought!

 

[C R]

Thanks; I realise that although I think the bars coming loose relative to the wheel is certainly enough to cause disaster in its own right

In my experience, the bolt will not let go suddenly, it just slips slightly, DAMHIKT.