I've used Ebay finds to [censored] up an old MTB frame (Shogun Trailbreaker) from the early 1990's because it fits me well, purports to be CrMo steel and is of non-compact format without the characteristic willowy seatpost.
While renovating it I was intrigued to find that the steerer tube is threaded 1 1/8" size which takes a 1" quill stem with wedge. I'm more used to the skinny steerers and quills on elderly road bikes.
I wonder if it is possible to convert to a fork with threadless steerer tube simply by fitting a threadless headset? The excellent Mr Sheldon Brown's pages suggest that the frame cups for both threaded and threadless 1 1/8" headsets are 34 mm od if I am reading him right.
I don't particularly want to take it apart again and bash out the frame cups unless I'm sure so I'd like to hear from anyone who's done it.
I wonder if it is possible to convert to a fork with threadless steerer tube simply by fitting a threadless headset?
For a 1-1/8" or 1-1/4" headset, yes. For a 1" headset, maybe. ISO (30.2mm cups) and BMX (32.7mm cups) one inch headsets have threadless versions. JIS (30.0mm), French, etc. are available only in nutted versions.
Quoted message said:
I don't particularly want to take it apart again and bash out the frame cups unless I'm sure so I'd like to hear from anyone who's done it.
Go ahead; there is only one set of diameter standards for 1.125" headsets, and they are all compatible with the same head tubes.
JIS (30.0mm), French, etc. are available only in nutted versions.
I spoke too soon. Assuming that a normal ISO threadless fork is used, French 1" frames can be converted to threadless, since they have the same 30.2mm cup outside diameter as ISO. JIS frames would be convertible to threadless if they were reamed to a 30.2mm bore size.
JIS (30.0mm), French, etc. are available only in nutted versions.
I spoke too soon. Assuming that a normal ISO threadless fork is used, French 1" frames can be converted to threadless, since they have the same 30.2mm cup outside diameter as ISO. JIS frames would be convertible to threadless if they were reamed to a 30.2mm bore size.
Chalo
Nashbar carried a JIS threadless headset for a while, for an RST 1- inch fork they had. It's long gone, but it did exist.
JIS (30.0mm), French, etc. are available only in nutted versions.
I spoke too soon. Assuming that a normal ISO threadless fork is used, French 1" frames can be converted to threadless, since they have the same 30.2mm cup outside diameter as ISO. JIS frames would be convertible to threadless if they were reamed to a 30.2mm bore size.
Sheldon "Numbers" Brown +--------------------------------------------------------------------- + | It is amazing how much "mature wisdom" resembles being too tired. | | --Robert A. Heinlein | +--------------------------------------------------------------------- + Harris Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide http://captainbike.com Useful articles about bicycles and cycling http://sheldonbrown.com
"Chalo" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Peter Howard said:
I wonder if it is possible to convert to a fork with threadless steerer tube simply by fitting a threadless headset?
For a 1-1/8" or 1-1/4" headset, yes. For a 1" headset, maybe. ISO (30.2mm cups) and BMX (32.7mm cups) one inch headsets have threadless versions. JIS (30.0mm), French, etc. are available only in nutted versions.
Quoted message said:
I don't particularly want to take it apart again and bash out the frame cups unless I'm sure so I'd like to hear from anyone who's done it.
Go ahead; there is only one set of diameter standards for 1.125" headsets, and they are all compatible with the same head tubes.
Chalo
So it's do-able. Thanks! And thanks to all others who replied. Guess I can start looking out for the right fork.
"Chalo" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Peter Howard said:
I wonder if it is possible to convert to a fork with threadless steerer tube simply by fitting a threadless headset?
For a 1-1/8" or 1-1/4" headset, yes. For a 1" headset, maybe. ISO (30.2mm cups) and BMX (32.7mm cups) one inch headsets have threadless versions. JIS (30.0mm), French, etc. are available only in nutted versions.
Quoted message said:
I don't particularly want to take it apart again and bash out the frame cups unless I'm sure so I'd like to hear from anyone who's done it.
Go ahead; there is only one set of diameter standards for 1.125" headsets, and they are all compatible with the same head tubes.
Chalo
So it's do-able. Thanks! And thanks to all others who replied. Guess I can start looking out for the right fork.
