i know some of you will say it can't be done and that i'm a stupid lier. I will assure you though you can put a 1 1/8" threadless fork in a old 1" frame with no machining cutting or grinding want to know how? take just an old 1" headset cup and a pair of 1 1/8 forks slide the cup over the fork HEY IT FITS !!!!! now take a frame with 1" headset cups in it and the rest of a threadless setup forks stem the secret is in the headset get the cheapest smallest diacomp aheadset or the tank and mabye a few others (i use the cheap one why pay for tank cups when you don't use them anyway) use everything but the cups so bearings upper and lower race everything but the cups with your 1" frame and 1" cups the biggest 1" cups you can get i think like a tange or mabye a bear trap or odysey i'm not sure i just took old 1" cups untill i found one the 1 1/8" bearings fit in and put it all together. IMPORTANT you cannot use the 1" bearings also on some 1pc machined forks the taper for the race starts to soon and hits the cup (see grinding) i know i said no grinding but you don't have to with most forks and no matter what the bearings fit a little tight in the cups not bad but a little tight it worked great for me but if you don't like it freeball the cups (bearings no cage) this is tough and most won't want to do it if you do leave space for one to two bearings missing top and bottom so no bindind. try it out tell me what you think or if you have any ? let me know if there is alot of intrest i will get more detailes for you i have done this on at least 10 bikes and have 6 years bike shop mechanic experience (i got board one winter playing in the partas drawer) hope this helps someone.

Much easier way than looking for small bearing retainers, just use loose balls and pack the cups full of grease to get them seated till you get the forks on.

Much cheaper also because its not that hard usually to find fork and upper races from people if you ask around.

i mentioned the freeball method above but i'm glad you guys know about it

it works the other way, too - 1" fork in a 1 1/8" frame.

For the opposite way you can just buy some shims from Dan's Comp to put the 1" headset in the 1 1/8" frame.

King makes a 'devolution' headset for 1" forks into a 1 1/8" frame, works like a champ. I tried the shims first and ended up with a broken collar on the 1" headset.

I

Sorry, no idea why the message above didn't work properly.

I had a 1" Prolite threadless fork & 1" Hoffman stem. When I bought a new frame, it was a 1 1/8" headtube. Buying new forks, headset & clamp was a painful prospect.
I managed, with some help from G. of G-Sport, to locate some Rekka adaptor cups. They worked a treat and were possibly stronger than ordinary cups due to the extra metal. Looked quite nice, too. Sort of 'industial', no frills.

Sadly, I don't think they're available anymore, and the bike's long gone. I hope the thieving runt had a good time working out why nothing up front would fit other bikes.