brooklyn

I have done my searches and still i am condfused. I needed to change my 1 inch treaded headset on my khs with a new hatta swan headset. I removed the race from the fork crown to realize that the original was a 26.4 and the one from the hatta was a 27.0. if i have read correctly

1. the hatta headset willl not fit since the cups are larger than my frame will allow. If i want to install i will need to bring the frame to a good bike shop to have them modify the headtube so it will fit the new cups?
2. if this is done what can be done a about the race for the fork? since the 27.0 on will not fit can i use a new 26.4 race with the hatta headset?

or should i just press the new cups in and use a new 26.4 race and call it a day?

moxfyre

I think you must have it backwards, a 27.0mm (JIS) headset will be *too loose* to fit a frame/fork meant for 26.4mm (ISO) headsets. See Sheldon Brown's headset sizing: https://sheldonbrown.com/gloss_ha-i.html#headset

If you are trying to replace the 26.4mm (ISO) headset with a 27.0 mm (JIS) headset, the JIS will be TOO LOOSE. If that's is the case, then you should return the JIS headset and get a properly-fitting ISO headset. Since ISO is the modern standard size there's a better selection anyway.

If you're trying to replace a 27.0mm (JIS) headset with an 26.4mm (ISO) headset, then the ISO headset will be too small to fit, as you've described. The solution in this case is to machine the fork crown to a slightly smaller diameter to fit the ISO fork crown race. I think a pretty well-equipped shop will have the equipment to do this.

I guess you could mix-and-match the races from the old and new headsets. That might work okay, but then again why replace the headset if the races are good?

freako

Why don't you do your searches somewhere else and stop posting the same question 3 fulken times!!!!!

moxfyre

Woah... chill The duplicate post could be due to the fact that the Submit button often doesn't appear to be working when the server is slow.

wroomwroomoops

bikeforums had a database problem the other night (last night?) and there was a TON of duplicate threads started. And this isn't the first time, either, so, please, update your knowledge of these things.

Sometimes threads are actually deleted, in these database mishaps.

brooklyn

didnt think of that. maybe next time i will do that

thanks to everyone else for replying to my question