larrylokane

I've been doing some extensive research on this. As I have an old Peugeot 501 frame for the build I'm currently doing and I'm struggling to find some 1" rigid forks to fit the 1" head tube. I've been looking possibilities of reaming out the HT to fit a 1 1/8" headset and/or machining down a 1 1/8" head set to fit a 1" head tube.

Since then I've found 2 guys in the US who make they're own 1" head sets to fit a 1 1/8" fork steerer. I think there's a lot of older American frames/cruisers and bmx's that have 1" head tubes. But this is ideal because it means you can run newer gear on an older frame.

So my question is, instead of me forking out $45-$50 dollars + delivery + whatever import taxes I might have to pay... does anyone in the UK make these? Maybe a frame builder?

unterhausen

I assume Jamie Swan is one of the guys, who is the other?

larrylokane

Jim and Paul at 'Genuine Bicycle Products .com'

and another dude named 'ChattyMatty' over on BMX Museum forum

If I can find someone in the UK that would make my life a whole lot easier

unterhausen

I don't think the Genuine Bicycle Products headset will fit your Peugeot anyway. Different size head tube Genuine Bicycle Produsts: Parts and Accesories.

dsaul

The math just doesn't work on that. A standard head tube for a 1" steerer has a 30mm internal diameter. An 1 1/8" steerer tube is 28.6mm, which leaves a difference of 1.4mm. Divide that 1.4mm by 2 and you get .7mm of clearance between the steerer and the head tube. Allowing for a .1mm clearance between the steerer and the headset cup leaves a .6mm wall thickness for the cup. Even with a steel cup, that is not thick enough for safety.

unterhausen

I can't disagree with your math, but I swear I read somewhere that Jamie Swan did this. But I find no evidence on his flickr.

Crummy U.S. built bikes BITD used a larger head tube for some reason, even with 1" steerers. BMX stuck with that dimension even after people started making better bikes. Same with bottom brackets. That allows a lot more space and room for a headset to be modified.

larrylokane

Ye you're right about that. I've spoken to Paul at GBP and he said for this to work the ID of my head tube must be 32.5mm. Maybe thats the standard for the vintage American bikes. My Peugeot is in for powder coating right now so I will have to do the measurements when I get it back next week. I've found some 1" forks on US ebay which are exactly what Im looking for style wise so I think I need to weigh up my options, check my bank account and see whats the best bet

unterhausen

isn't Hilary Stone still around? I would think French ebay would also be an option.

bulgie 

I think what you're thinking of is when Jamie took apart a 1-1/8" Viscoset steering damper headset and manufactured new cups to cram the Viscoset mechanism into a 1" headset. Photo album here.

He was still using a 1" steerer in a HT made for 1" steerer in that project.

- Mark B in Seattle

larrylokane

thanks for the tip! I never thought to check french ebay either

David Tollefson

Could the head tube cups not be manufactured to press onto the outside of the tube, rather than the inside?

bulgie 

Now that's "thinking outside the head tube" as they say.

But no, not really, for 99.99% of bikes on the planet. The HT outside is not a precision surface, what with lugs or weld beads and warping/distortion from brazing or welding. HT insides have been reamed to fit since time immemorial, but no one makes a precision tool to mill the outside. Even if you made the tool, due to inconsistencies in how close the weld bead or fillet comes to the ends of the tube, you get only a small and variable amount of cylindrical surface suitable for milling. Headsets need more than that to ensure they're on-axis with no wiggle/slop.

Unless you're envisioning a bike intended from the get-go to have this external headset? That I could see. But retro-fitting existing bikes, not likely.

Mark B in Seattle

fietsbob

Putting a 9/8 fork in a 1" frame is like trying to put 8# of stuff in a 5# bag..

Hire the fork made for you rather than "Find" it ready made ... the parts for making forks of that size/type are still being made..

NB: this is the framebuilders section after all..

guy153

Good point about how there's not enough room. The regular headset is usually behind the welds and you're reaming out the back of them. There also might be a risk of crushing the HT if you had the kind of interference fit that is used on the inside on the outside.

​​​​​You might be able to make a braze in cup design like Columbus already use. It would slot inside the HT but only need a few mm of insertion. But it might be easier to modify the fork.

apollodriver

hi there - good day

many many thanks for this very intersting discussion. this is pretty helpful!

larrylokane

Update:

I went with the rigid forks from America. Cost me £106 shipped so not on the cheaper side but very happy with them. They have a 1” steerer tube which was extra long 250mm which is exactly what I needed for my Peugeot frame. Bought an Mart 1” threadless headset which came with both 27mm and 26.4mm crown race as I needed the 27mm which were also not very easy to find but got there in the end!

thanks all for your helpful input