Fitting 1 inch steerer into 1 1/8 inch head tube

[Andy61]

I want to fit a fork with a 1 inch threaded steerer into a frame which currently has a 1 1/8 steerer. I have the replacement fork already so its not just something I'm considering. It was described as 1 1/8 inch steerer when I bought it. I thought it would be quite simple - just fit suitable shims to reduce the headtube to the size to accept the bearing cups for the 1 inch threaded headset. Well its not turning out that way, so far, I can't find any suitable shims. My headtube inner diameter is 44mm (I think the measurement is actually 43.9mm but I can't measure that accurately) and this needs to be reduced to 30mm to accept the 1 inch headset bearing cups. There are various shims that are for converting 1 1/8 headtubes to 1 inch headsets for use with 1 inch steerer forks, but none that I've found are for 44mm inner diameter headtubes. There are apparently (at least) four different inner diameters for headtubes that are called 1 1/8 inch (https://en.wikipedia.org/wiki/Head_tube), (33.8mm, 41.1mm, 41.9mm, 43.9mm) mine is the largest - zero stack / internal.

My first question is, does anyone know of a source for a pair of shims to reduce a headtube from 43.9mm internal diameter to 30mm internal diameter?

When testing the fork in the frame to check lengths and handle bar position, I noted that the existing integrated threadless headset has bearing races that seam to be 30mm internal diameter, and checking on-line, headsets that have bearing cups that with an outer diameter of 44mm have bearing races with inner diameter of 30mm. I had an old 1 inch threaded headset lying around in the garage and I managed to press (using a home made cup press tool - threaded rod with end plates and a couple of nuts to wind it tight) the upper cup into the bearing race of the existing integrated headset (nice tight fit). The bottom bearing cup would not press fully home into the existing integrated headset. Maybe if I persevered a bit more it might, but it could be that the metal of the original bearing race does not have the same give as the headtube itself and it will never press in fully. I then had double bearings at the top and the bottom of the headtube. The existing bearings were just really acting as shims, though they still rotated. The old headset I had lying around is not suitable for use as it is badly worn. If I decide to use this approach I will buy a new 1 inch threaded headset.
Has anyone come across this method of doubling up the bearings to fit a 1 inch steerer into a 1 1/8 inch headtube?
I can't think of a good reason why this shouldn't work. It might look a bit odd and would increase the stack height a bit (I'm not bothered about increasing the stack height as it is a tourer and am not seeking a low handlebar position).

You might wonder why I want to change to fork in the first place. Well the original is dead straight and the fork arms are like a pair of scaffold poles which gives a really hard ride on the front end, the replacement fork (steel) has nicely tapered and curved fork arms so should give a much smoother ride damping out a lot of the road unevenness (I have an old (65 years) 531 steel fork on another bike and that gives a nice smooth ride on the front end).

Any helpful suggestions would be gratefully received.
Andy

[pwa]

Sjs have alloy headset reducers. Is that what you need?

[Brucey]

yup headset reducers, that is what you need!

cheers

[Andy61]

pwa - thanks, but SJS do not say what size they are, simply saying 1 1/8 inch is not enough as there are four sizes. I have seen 1 1/8 to 1 inch adapters that turn out to be 34mm outer diameter, no good for my needs. I have emailed SJS to ask for precise measurements.

Brucey - I know I need headset reducers. Where can I get ones the size I need? As I said I haven't been able to find any.

[andrew_s]

mine is the largest - zero stack / internal
---
Where can I get ones the size I need? As I said I haven't been able to find any.

I suspect that the available headset reducers are all for traditional external cup headsets.

[Redvee]

BETD have them too

http://www.mountainbikecomponents.co.uk ... t+Reducers

[pete75]

I want to fit a fork with a 1 inch threaded steerer into a frame which currently has a 1 1/8 steerer. I have the replacement fork already so its not just something I'm considering. It was described as 1 1/8 inch steerer when I bought it.
Andy

If the vendor wrongly described the forks as having a 1 1/8" steerer when they did not you are entitled to your money back. Returning them and buying a pair with the correct steerer size seems the best option instead of faffing about with shims and the associated cost along with the expense of a new headset.

[CREPELLO]

I want to fit a fork with a 1 inch threaded steerer into a frame which currently has a 1 1/8 steerer. I have the replacement fork already so its not just something I'm considering. It was described as 1 1/8 inch steerer when I bought it.
Andy

If the vendor wrongly described the forks as having a 1 1/8" steerer when they did not you are entitled to your money back. Returning them and buying a pair with the correct steerer size seems the best option instead of faffing about with shims and the associated cost along with the expense of a new headset.

+1

[Brucey]

I've had several sets of reducers; they have come to me installed in cheap bike frames. Thinking about it none have been the exact size you are seeking; that might require cranking the lathe up perhaps, if you can't find any the size you want.

However if you want a nice set of 1-1/8" forks I may have some!

cheers

[pete75]

There you are - get your money back and buy a set of forks from Brucey