Author Topic: Head bearings  (Read 405 times)

Offline AndyD

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Head bearings
« on: October 20, 2020, 11:28:16 AM »
Just been fitting steering head bearings to the CJ250T (I know it's not the 400 but very similar!) and had the same issue as on the 400 where the tapered bearings reduce the clear thread on the adjustment nut.
These are JMT bearings from Wemoto, on the 400 I had the same issue with All Balls ones.
After the 400 problems and having the old original bearings to hand I took time to measure them and the bottom one with washer supplied is exactly the same height, the top one comes out around 0.9mm higher.
Once fitted this allows about 2 to 2.5 full turns of the adjustment nut and I wondered if this is enough to be safe or if I need to do further work to get more hold on the thread.
Cheers,
Andy

Offline K2-K6

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Re: Head bearings
« Reply #1 on: October 20, 2020, 01:51:29 PM »
It's not a big risk as virtually all structural loading is imparted by the clamping bolts of the triple clamps.

Certainly a nice to have accurate placement in matching original but unlikely to make much difference as its it's really just positioning the top end to facilitate the clamp bolts being correctly tightened.

All of the load sits on the bottom race to support the bike,  the top bearing ultimately to keep the assembly aligned.

Offline AndyD

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Re: Head bearings
« Reply #2 on: October 20, 2020, 06:47:51 PM »
Many thanks, that's reassuring and happy now to move on with build.
I guess it just feels wrong to have so little thread
Annoying that they can't just get the parts made correctly - seems it's only a problem with certain models as I've fitted new head bearings to various Suzuki and Honda bikes over the last few years and none have had any issue.

Cheers,
Andy

 

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