Originally Posted by
thehammerdog
im debating the upgrade to suspension first....the 7 speed stuff works well. got new lighter cranks ebay on way...fun comfy bike
That looks like a head tube for a 1” steerer tube. Around the mid-90’s they went to 1-1/8”. And today just about everything is 1-1/2 tapered.
I usually hate using the term impossible, but finding a decent used suspension fork with a 1” steerer is about as close as you can get. Early Rockshox (Mag, Quadra) were made in 1”. Other mfg’s also, but many were not very good.
The only 1” I would consider, that you might run across, is a Marzocchi. There were a few years where Marzocchi made a fork crown with a removable steerer tube. This means you could swap out the steerer. Really tough to find a Marzocchi 1” steerer. Up to 10 years ago, RST made 1” steel steerer that would work, but equally as tough to find these days.
John
Edit added: If you do look for an older Marzocchi fork, stay away from the early XC (500/700) forks. Z series (2, 3) are fine.