Six jours
10-31-07, 12:11 PM
Kind of an extension of my wide flat crown thread. I can't find a flat crown with 50+ mm tire clearance and 1" steerer, but there are several that fit the bill in 28.6. I really don't want to deal with the OS headset, threadless stem, etc.; I just want a nice traditional front end. I've read that it's possible to braze in a sleeve between a 28.6 crown and a 1" steerer, but have seen no details. I'm assuming that the sleeve must extend from the bottom of the crown to the top of the crown race, and then the crown race is turned down -- essentially shaved off entirely, including the braze/filler -- so that the race seats on the turned-down bit of the sleeve.
Does this sound right? Has anyone had any experience with this? And what are the potential problems?
TIA!
superhotbug
10-31-07, 12:33 PM
I have an old crown from an exxon graftek , don't know how wide it is but I could measure it and I also have some threaded steerer tubes that are real long, ready to solder. Doug
Six jours
10-31-07, 01:18 PM
Huh. Weren't the Graftek crowns carbon-wrapped steel? And didn't they break? Sorry for the foggy memory here, but it's been a while...
superhotbug
10-31-07, 01:34 PM
No, the graftek forks were just chrome forks with a recess area on the fork tube where carbon was wrapped for looks. The crown is old school, flat topped heavy for 1 inch steerer. I'll look tonight and post the width tomorrow.
velonomad
10-31-07, 08:46 PM
Kind of an extension of my wide flat crown thread. I can't find a flat crown with 50+ mm tire clearance and 1" steerer, but there are several that fit the bill in 28.6. I really don't want to deal with the OS headset, threadless stem, etc.; I just want a nice traditional front end. I've read that it's possible to braze in a sleeve between a 28.6 crown and a 1" steerer, but have seen no details. I'm assuming that the sleeve must extend from the bottom of the crown to the top of the crown race, and then the crown race is turned down -- essentially shaved off entirely, including the braze/filler -- so that the race seats on the turned-down bit of the sleeve.
Does this sound right? Has anyone had any experience with this? And what are the potential problems?
TIA!
Sounds reasonable to me. the closest slip fit size for the sleeve would be 1.1/8" (28.6) x.058" which works out to 25.7mm ID, you might have to fiddle with it a bit to keep the sleeve and steering tube precisely parallel while brazing