I'm installing my first threadless headset. Everything went on fine. Now I'm trying to install the star nut (star-fanged nut). It seems significantly larger than the inside diameter of the steerer tube. I'm game for installing without the special ram-tool. I'm sure I could do it with a socket and small maul. I just want to be sure that this nut really should go into this steerer. Do they come in more sizes than just for 1 1/8 headsets? Maybe I have a thickwall steerer... Just to see if I'm on the right track, I screwed in the bolt and centered it and tried tapping it down into the opening a bit. It didn't seem like it wanted to go in. Seems a good 1/16th larger in diameter or more. Do the flanges bend/fold in quite a bit? I can make sure my fork-ends are resting on a 2x4 so that force isn't harsh on them but I want to be sure. The friend who I got the frame, fork and headset from said it all went together but he has a big scattered shop... Doublechecking here... And trying to get this done now. Not that I'm in a rush, but sheesh. I hate to get rolling then get stalled out. Thanks! --JP

Star nuts are available for 1", 1 1/8, 1 1/4,and 1 1/2" steer tubes. If it's about 1/16" oversize, I'd say you have the correct one. They are supposed to collapse to fit the inner diameter of the tube. That's what holds it in place.

If you look at this page:

https://www.speedgoat.com/product.asp?part=130534

it would appear that there are different size star nuts for aluminum versus steel steerers. Not sure that knowing that helps you much, but it does seem to be true that there is more than one size to consider for a 1 1/8" outside diameter steering tube.

I've had trouble getting some star nuts to stay put in thin-walled steel steerers, so I can confirm that not all 1 1/8" star nuts are equal.

Yeah, that's my worry.

My lame old calipers say the steerer has an ID of 31/32" (less than an inch). And my star-nut is 1 3/32". (A bit more than a 1/16" bigger than an inch.) So we're talking an overhang on all sides of 1/16", or a 1/8" diameter difference. Sound like the right thing? Sounds like it MIGHT be.

Or, do I have a steel steerer star-nut somehow? (My pal was a racer with high-end extra-light bikes. Why would he have a steel steerer fork? Maybe he got it accidentally as well...)

Thanks, JP

PS: Hey, thanks everyone -- it all worked out fine. I hit it a few times with a small maul using a small socket over the star-nut bolt and it went in dandy. I just wanted to be sure. So I'd say that 1/16" overlap all around means you have the right size. --JP

I know you have like 1/8 and 1/4 starnut
Sizes, But
what does that mean?

not sure where you saw those dimensions... 1.125"(1 1/8") and 1.250"(1 1/4") is the outer fork steerer tube size, and the star nuts are designed to be springy... they fit quite tightly into the fork tube.

MOST star nuts are for the 1 1/8" fork tubes... the 1 1/4" size are fairly rare.