Install 1 1/8" fork instead of 1"
10-31-19, 11:21 AM
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Install 1 1/8" fork instead of 1"
There are lots of topics in regard to the problem of 1" fork replacement. The retro tandems have 1" fork that is expensive as it is not mass produced. As far as I know 1 1/8 " are available from 100$. I found two solutions on russian speacking forums, how to install the 1 1/8" fork on older bikes. I try to explain them here breefly. Probably it helps somebody to use its lovely retro tandems again.
Fortunately the outer diameter of the steerer tube is 28.6 (1 1/8") and the inner diameter of the old head tubes is about 30 mm. So modern steerer tube passes through the old head tube. The only problem is the headset, it can't be installed directly to the head tube, as it would have a too thin wall. Therefore the main idea is to connect the modern headset to the head tube externally. The only requirements is that the head tube has to protrude about 5..8 mm from the top tube and the down tube.
Method 1 is simple, cheap and not so nice looking. Some bikes have the head tube with outer diameter about 34 mm. The outer diameter of the headset cape for the 1 1/8" fork is also about 34 mm. And there are seat clamps with inner diameter of about 34 mm. The rest would be clear from pictures. But I am not aloud to post them, as it is my first post here. If somebody, who is able to insert pictures or links, is intersted, I could give links in private message.
The soultion was tested also on tandem. No problem after 1000 km in different conditions.
Method 2 is nicer and requires the turning. The adapter for the headset should be made like shown in pictures: [here have to be links]
It is just a cape with the inner diameter eqauls the outer diameter of the head tube from one side, and fit the headset from the other side.
The size depend, of course, on the headset and the frame.
Fortunately the outer diameter of the steerer tube is 28.6 (1 1/8") and the inner diameter of the old head tubes is about 30 mm. So modern steerer tube passes through the old head tube. The only problem is the headset, it can't be installed directly to the head tube, as it would have a too thin wall. Therefore the main idea is to connect the modern headset to the head tube externally. The only requirements is that the head tube has to protrude about 5..8 mm from the top tube and the down tube.
Method 1 is simple, cheap and not so nice looking. Some bikes have the head tube with outer diameter about 34 mm. The outer diameter of the headset cape for the 1 1/8" fork is also about 34 mm. And there are seat clamps with inner diameter of about 34 mm. The rest would be clear from pictures. But I am not aloud to post them, as it is my first post here. If somebody, who is able to insert pictures or links, is intersted, I could give links in private message.
The soultion was tested also on tandem. No problem after 1000 km in different conditions.
Method 2 is nicer and requires the turning. The adapter for the headset should be made like shown in pictures: [here have to be links]
It is just a cape with the inner diameter eqauls the outer diameter of the head tube from one side, and fit the headset from the other side.
The size depend, of course, on the headset and the frame.
