Holdsworth Mistral Headset

[Hanlon]

Having a nightmare fitting a headset to my restored 1970s Holdsworth Mistral frame and would welcome some sage advice please. Bike shop tried to fit my standard Campag Record NOS headset - crown race too small for the fork crown. Advised by bike shop that I needed a JSI headset. Obtained a lightweight Velo Orange one and the bike shop promptly broke the alloy crown race trying to fit it Frame restorer had coated the fork crown bearing surface liberally with primer and though I'd asked the bike shop to remove it, they'd left it on. Naturally I pulled the frame out of the shop (after some stern words !) and obtained a second JSI headset. Now tackling the job myself - as I wish I had to start with - I have the following questions:
1) Is it correct that Holdsworth used oversized (JSI equivalent) fork crowns on the Mistral ?
2) To remove Campag top and bottom cups from head tubes I've always used a wooden drift and mallet from the outside - is there a better way ?
3) What is the best type/brand inexpensive tool to press the new cups in place ?
4) How do I ensure I don't break the second JSI alloy crown race and how best to fit it ?
Thanks guys

 

[midlife]

It's really unusual for that frame to have a Japanese / JIS headset. Some cheaper frames from that era had imported forks with that size but not Holdsworth.

Is there a lot of paint on the forks stopping the Campag race from fitting?

 

[Hanlon]

It's really unusual for that frame to have a Japanese / JIS headset. Some cheaper frames from that era had imported forks with that size but not Holdsworth.

Is there a lot of paint on the forks stopping the Campag race from fitting?

Not sure how much primer is on there.....I guess I'll have to scrape it off and get a micrometer on it. It was my father's bike and had a rather "agricultural" old heavy steel headset fitted so I'm tempted to think it's a non standard size. All his other bikes had Campag or Shimano lightweight headsets and I feel sure he'd have treated the Holdsworth to one as well ......and may have encountered the same issue as me ?

 

[midlife]

Even old heavy steel headsets were ISO sized . Are the forks the original?

 

[Hanlon]

Even old heavy steel headsets were ISO sized . Are the forks the original?

Yes I am sure forks are the original - correct lugs and dropouts. Time to get the micrometer out, clearly !

 

[Hanlon]

Micrometer shows (readings approximate because measuring inside a circle with my instrument is tricky) :
Old Holdsworth crown race internal diameter 26.86 mm
Standard Campag crown race 26.26 mm
New JSI Velo Orange crown race 26.86 mm - same as original crown race !
SO Holdsworth appear to have made that frame for an oversized headset

 

[midlife]

Very strange, do the fork dropouts match the rear, BITD you could buy cheap Tange forks if the originals got bent.

 

[goldcoastjon]

Having a nightmare fitting a headset to my restored 1970s Holdsworth Mistral frame and would welcome some sage advice please. Bike shop tried to fit my standard Campag Record NOS headset - crown race too small for the fork crown. Advised by bike shop that I needed a JSI headset. Obtained a lightweight Velo Orange one and the bike shop promptly broke the alloy crown race trying to fit it Frame restorer had coated the fork crown bearing surface liberally with primer and though I'd asked the bike shop to remove it, they'd left it on. Naturally I pulled the frame out of the shop (after some stern words !) and obtained a second JSI headset. Now tackling the job myself - as I wish I had to start with - I have the following questions:
1) Is it correct that Holdsworth used oversized (JSI equivalent) fork crowns on the Mistral ?
2) To remove Campag top and bottom cups from head tubes I've always used a wooden drift and mallet from the outside - is there a better way ?
3) What is the best type/brand inexpensive tool to press the new cups in place ?
4) How do I ensure I don't break the second JSI alloy crown race and how best to fit it ?
Thanks guys

Hanlon - The choices for fork crown race inner diameters BITD were 26.4 mm or 27.0 mm. I have a Jack Taylor whose fork crown seat was hand-filed and is not perfectly round, too: that may be another issue. What is the ID of the original "agricultural" fork crown race?

A simple home tool for installing the cups can be made with a long piece of threaded rod (at least 5/8 inch but smaller than the head tube ID and 2-4 inches longer than the HT) with nuts and heavy-duty fender washers...

 

[carpenter]

I bought one of these, and very happy with it (not sure that I could do it cheaper myself):

https://www.ebay.co.uk/itm/HEADSET-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[midlife]

Sheldon has a good crib sheet for headsets

https://www.sheldonbrown.com/cribsheet-headsets.html

 

[Hanlon]

Hanlon - The choices for fork crown race inner diameters BITD were 26.4 mm or 27.0 mm. I have a Jack Taylor whose fork crown seat was hand-filed and is not perfectly round, too: that may be another issue. What is the ID of the original "agricultural" fork crown race?

A simple home tool for installing the cups can be made with a long piece of threaded rod (at least 5/8 inch but smaller than the head tube ID and 2-4 inches longer than the HT) with nuts and heavy-duty fender washers...

Thanks goldcoastjon. The ID of the original "agricultural" headset was the first one I quoted - 26.86 mm. That neatly corresponds to the size of the Velo Orange JIS headset that I bought. I suspect my fork crown seat may also not be perfectly round. I'll spend some time checking it with the micrometer - oh the joys of vintage bicycles

 

[Hanlon]

Very strange, do the fork dropouts match the rear, BITD you could buy cheap Tange forks if the originals got bent.

Yes they do seem to match and are Campag pattern (if not actually Campag) Though my late father clocked thousands of miles commuting to work from north London to Belgravia and did "do" the forks of his Alan frame when a car helpfully stopped dead in front of him. So it's possible the same happened to the Holdsworth and new forks were fitted

 

[Hanlon]

The frame is boxed up waiting for assembly so I'll get it out and post some pix of the forks when I get a chance......I bet someone will be able to judge if they are Holdsworth originals

 

[midlife]

They should have the same frame number stamped on them?

 

[rogerzilla]

SOP for JIS framesets is to re-cut them to ISO (26.4mm crown, 30.2mm ID head tube). I've done several. Any half decent bike shop has the tools.

Btw, never re-cut a Raleigh-threaded frameset unless you are also swapping the fork for an ISO threaded one. Raleigh headset dimensions are the same as JIS but the threading is 26tpi. You cannot rethread a fork from 26tpi to 24tpi unless you braze in a new steerer!