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-   -   What's the pre-load torque for a Chris King 1-1/8" threadless headset? (https://www.bikeforums.net/showthread.php?t=1202372)

masi61 05-23-20 09:16 AM

What's the pre-load torque for a Chris King 1-1/8" threadless headset?
 
I like the front end of my bike to be as taut as possible. I seem to notice that the front end of my bike develops a slight bit of slop in the handling about once a year. So I loosen my stem bolts and verify that the fork plug is snug enough and then re-do the preload on my cap bolt (without a torque wrench) and finally make sure my stem bolts are tightened correctly.

The tautness is there now, but I fear I may have overdone it with the pre-loading of the sealed bearings on the Chris King headset. I thought I felt a slight bit of notchyness but the handling on the road is good and no hands riding is good. Does anyone know if these Chris King bearings will be damaged if I go (slightly) overboard snugging up the fork plug cap screw?

Andrew R Stewart 05-23-20 09:53 AM

https://cdn.shopify.com/s/files/1/29...63412763896395 Scroll down to final assembly and adjustment. BTW this took about 45 seconds to find. Andy

masi61 05-23-20 10:48 AM


Originally Posted by Andrew R Stewart (Post 21492473)
https://cdn.shopify.com/s/files/1/29...63412763896395 Scroll down to final assembly and adjustment. BTW this took about 45 seconds to find. Andy

Thanks for the link. I suspect I put more than 6 to 15 inch pounds of torque on the cap screw. I like the way the front end is handling though.

bitpuddle 05-23-20 11:12 AM

Just enough to hold the headset together. As soon as you can apply the front brake and rock the bike back and forth without movement in the headset, you’ve tightened enough. Barely more than finger-tight.

If your headset loosens, you might have issues with the frame prep (head tube not faced/parallel, unevenly reamed, too of steerer not cut at 90 degrees, etc).

stevoo 05-23-20 11:35 AM

Deleted

Crankycrank 05-23-20 02:34 PM


Originally Posted by bitpuddle (Post 21492604)
Just enough to hold the headset together. As soon as you can apply the front brake and rock the bike back and forth without movement in the headset, you’ve tightened enough. Barely more than finger-tight.
If your headset loosens, you might have issues with the frame prep (head tube not faced/parallel, unevenly reamed, too of steerer not cut at 90 degrees, etc).

+1. I never use torque readings for headsets. Easy way to check for sure is to put everything together, lift bike with the front end pointing down, turn front wheel and let it return to center on it's own. You want it to be just tight enough so the the fork just starts to move freely without any binding. No more, no less. Removing the handlebar so that the cables don't interfere with movement is necessary though. As bitpuddle mentioned if you're having problems with a CK headset loosening you may need to check everything noted.

Andrew R Stewart 05-23-20 02:40 PM

As an old timer who cut his teeth on soft Campy headsets I learned to set things by rocking feel, after building up the bike. Usually for my own stuff I will fall on the lesser side of the fence as I'll revisit after a few rides. Now that Phil has brought out headsets my CK fling is pretty much over. I did like the CK feel when new but disliked the overhaul process. The tiny balls and lack of much space for grease didn't make me happy. But I will say the CK bearings do last a good while. Andy

davidad 05-23-20 10:46 PM


Originally Posted by bitpuddle (Post 21492604)
Just enough to hold the headset together. As soon as you can apply the front brake and rock the bike back and forth without movement in the headset, you’ve tightened enough. Barely more than finger-tight.

If your headset loosens, you might have issues with the frame prep (head tube not faced/parallel, unevenly reamed, too of steerer not cut at 90 degrees, etc).

The bearings require preload.

Russ Roth 05-23-20 11:28 PM

The issue of the headset coming loose isn't the headset, its the stem. The topcap only helps to set the preload but can't hold everything together, especially since it has nothing solid to connect to; a star nut or plug isn't really that strong. Instead its the stem that holds the works together and you need to make sure you're getting that properly tight, typically 5nm is the torque on the stem bolts but after tightening the second bolt you need to recheck the first bolt you tightened and after double check the second bolt. I've had to do as many as 3 checks as one bolt can lose some tension once the other bolt is tightened. Can also use fibergrip if a carbon steerer to help prevent slipping as well.

Litespud 05-24-20 06:28 AM


Originally Posted by masi61 (Post 21492396)
I like the front end of my bike to be as taut as possible. I seem to notice that the front end of my bike develops a slight bit of slop in the handling about once a year. So I loosen my stem bolts and verify that the fork plug is snug enough and then re-do the preload on my cap bolt (without a torque wrench) and finally make sure my stem bolts are tightened correctly.

The tautness is there now, but I fear I may have overdone it with the pre-loading of the sealed bearings on the Chris King headset. I thought I felt a slight bit of notchyness but the handling on the road is good and no hands riding is good. Does anyone know if these Chris King bearings will be damaged if I go (slightly) overboard snugging up the fork plug cap screw?

if I’m reassembling my front end (King threadless h/s, carbon fork) I get everything in place then give the stem a few GENTLE taps with a rubber mallet right at the steerer end, to ensure that everything is “bedded in” before I screw down the top cap. Once the stem bolts are torqued and both checked, the front end holds adjustment indefinitely. IIRC, the top cap torque is on the order of 2-3 Nm, but I usually do this by feel. I do torque the stem bolts, though


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