Stupid question......quill stems and a-headsets

Gerard · Jan 9, 2017

Sorry for the stupid question and please forgove me.
I'm building up my MT4 and I have 2 set of forks, the orginal Dynatech rigid with threaded steerer and Pace RC36 shocks without threaded steerer.

I was wondering if I could use a standard a-headset for both?
When the Dynatech forks are used I would use a quill stem with the nut on the thread (with spacer) to put the required pressure on the ahead set. The spacer and nut would cover any of the exposed thread on the steerer.

If I choose to switch to the Pace shocks I would just use a regular ahead stem and spacer.

I can't see in theory why this wouldn't work. I just don't want to be bothered swaping headsets, or cutting the Dynatech forks steerer down and ising an adaptor.

gradeAfailure · Jan 9, 2017

Re:

http://www.chainreactioncycles.com/mobi ... p-prod6254

You'd have to use a headset that had both threaded and threadless versions though.

ishaw · Jan 9, 2017

The bearing cover on the top will be threaded so unlikely to work with an unthreaded steerer. I seem to recall m-part doing a top for certain headsets allowing a conversion from threaded to ahead so might be an option if you can find one. Failing that, finding a headset that came in both flavours and swapping the top bits when you change forks.

Forgot to mention that most aheadsets use a split wedge that compresses against the steerer to hold it in place, a threaded headset uses the threads on the steerer for this, so in sheadset guise, your plan will equal a rattly and loose steerer in the headset I'm afraid.

Osella · Jan 9, 2017

Re:

The above is what I've been doing - depends on the length of the threaded steerer and the threaded portion of it too.
If you happen to have, or you can buy, a threaded upper top cover; fit the threaded forks and thread the threaded upper cap onto the steerer tube, as normal. Provided it fits over the aheadset top cup and rotates freely, you're good to go.
I have used this with DiaCompe threaded headset and both FSA Orbit type threadless cups and with cheaper M

art headset (all 'standard' EC34 type). If you've got some 'spare' threaded headsets, have a test!
It can be a PITA if you don't have a few lower crown races to experiment with though - as ideally you'd use the same crown race on both sets of forks (less messing about) - hence buying two sets identical isn't a bad call!

Not used these versions, but just as an example: [http://www.chainreactioncycles.com/uc/e ... at=product http://www.chainreactioncycles.com/uc/e ... at=product

The key is to check that there is sufficient thread on the steerer for the threaded top cover to firmly screw down onto. You can tighten it up pretty tightly though - and hopefully there's enough thread for the locknut as well(!). Then the usual - quill stem, expander, etc.
With no need to remove headset cups, it takes just a few mins to switch between threaded/unthreaded forks (well, if you're using front-loading stems..

)

Gerard · Jan 10, 2017

Re: Re:

Osella":22nejjyt said:
The above is what I've been doing - depends on the length of the threaded steerer and the threaded portion of it too.
If you happen to have, or you can buy, a threaded upper top cover; fit the threaded forks and thread the threaded upper cap onto the steerer tube, as normal. Provided it fits over the aheadset top cup and rotates freely, you're good to go.
I have used this with DiaCompe threaded headset and both FSA Orbit type threadless cups and with cheaper Mart headset (all 'standard' EC34 type). If you've got some 'spare' threaded headsets, have a test!
It can be a PITA if you don't have a few lower crown races to experiment with though - as ideally you'd use the same crown race on both sets of forks (less messing about) - hence buying two sets identical isn't a bad call!

Not used these versions, but just as an example: [http://www.chainreactioncycles.com/uc/e ... at=product http://www.chainreactioncycles.com/uc/e ... at=product

The key is to check that there is sufficient thread on the steerer for the threaded top cover to firmly screw down onto. You can tighten it up pretty tightly though - and hopefully there's enough thread for the locknut as well(!). Then the usual - quill stem, expander, etc.
With no need to remove headset cups, it takes just a few mins to switch between threaded/unthreaded forks (well, if you're using front-loading stems.. )

Thanks. Very Helpful. I plan to use an FSA Orbit MX. There is about 21/2-3 inch's of thread on which I was going to use lock nuts from and old threaded headset.
Your links to CR didn't seem to work.

itscervo · Jan 10, 2017

Just buy a threaded steerer for the Pace forks.

Osella · Jan 10, 2017

Re: Re:

Gerard":2ahg80tx said:
Thanks. Very Helpful. I plan to use an FSA Orbit MX. There is about 21/2-3 inch's of thread on which I was going to use lock nuts from and old threaded headset.
Your links to CR didn't seem to work.

Odd that the links to CRC didn't work.. Anyway, they sell some 'Brand-X' headsets dead cheap in threaded/unthreaded versions that are otherwise the same.
I've got a couple of the sealed bearing ones, the two I'd linked to are open caged bearings.
Aha, Orbit MX's are good headsets - however they are broad, so might not fit for your plan.. Orbit XL II are better, as the top cover goes over the whole headset, whereas with the MX, the cover is narrower than the top cup diameter and sits on the seals.

Stupid question......quill stems and a-headsets

Gerard

Senior Retro Guru

gradeAfailure

Senior Retro Guru

ishaw

Osella

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Gerard

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itscervo

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Osella

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