Fork crown too small for headset?!
 

I was planning on swapping my unbranded carbon fork for an unbranded steel fork to make my bike "tougher" for commuting, as well as possibly adding racks and full fenders without having to do annoying DIY work-arounds in the near future.

I haven't swapped the crown race yet, but even just by putting the steel fork into the headtube (both 1 1/8" threadless), it looks like the crown of the fork is too small for the headset!

On my carbon fork, the headset would have a "perfect fit" and sit on the crown nicely.

On this steel fork, the crown of the fork is basically "in" the headset, with ~4mm of the headset "hanging over" the crown of the fork.


EDIT: Oh I forgot to mention it's a Cane Creek Solos headset. The carbon fork's steer tube is not tapered.

The frame is a Kona JTS, approx 2007-8.

Does this mean I can't use the steel fork on my bike? I thought I could basically swap any 1 1/8" threadless fork with another!

Does your carbon fork have a tapered steerer tube????

That would make your straight steel steerer too small to fit the lower bearing assy without adaptors.

you might have to swap the crown race thats pressed down onto the fork.

I'm guessing this is a zero stack headset and head tube.

They look great with a beefy carbon fork sitting flush against them, but all kinds of wrong with a more traditional fork hanging out... but I bet the 1 1/8" crown race is the same on both forks, like the first two in the diagram.

http://bikeforums.net/attachment.php...hmentid=305955

Also, the carbon fork is likely a lot stronger than the steel fork, impact resistance aside.

Post a couple of pictures. I'm having a hard time visualizing what you're talking about.

Many forks, particularly carbon, have a rather wide crown race seat and the crown race will either be completely inside the seat or flush with the edges. I expect your steel fork has a smaller crown race seat and the race hangs over the edges by a bit. Not a problem and, in fact, an advantage since removing the crown race in the future will be a lot easier.

I edited my OP - it's a Cane Creek SOLOS headset in a 2007-8 Kona JTS, if that helps any. I don't think it's a zero-stack HS, and I'm almost certain it's not a zero-stack headtube.

As for the reason for swapping forks - I'm worried about the impact resistance since I've got lots of dings on my bike from other commuters locking up next to me, and I'd rather have a dinged up steel fork than a cracked carbon one. Plus, I figure having a steel fork will make my bike less attractive to thieves. I also want hassle-free rack and fender installation in the near future.

I'll see what I can do - I took some pics but they turned out really badly and you can't make out what I'm talking about.



I haven't swapped the crown race yet. The problem seems to be that the steel fork's crown race seat area is so much smaller that if I were to install the fork, the underside of the headset would be exposed to the elements (assuming the crown race fits).

There should be a plastic cover bridging the gap between the crown race and cup.

Wow, those pics must be super crappy... we pretty much just need a silhouette.

Okay so here's the best picture I can provide:

http://bikeforums.net/attachment.php...hmentid=306849

This is without any crown race (I haven't managed to get the crown race off of the carbon fork yet...). You can see that there's a small gap between the inner lip of the headset and the crown/crown seat area (not sure of the terminology) of the fork. On my unbranded carbon fork, the bottom of the headset sits flush with the fork crown, whereas here it's "hanging over" the steel fork.

I'm still having a hard time picturing what you are complaining about. Will it work mechanically once you get the race in place? I'm just wondering if its an aesthetic issue or a functional issue? Even if the seal is exposed, will the bearings still ride properly and function? If so then I imagine that you just need to find a headset with a good seal.

If I'm reading you correctly, the issue is that the crown race is overhanging the crown front and back.

If that's the issue, there isn't one.

Historically steel fork crowns were made narrow enough for the races to overhang. This made it easier to knock them off with a U-shaped tool. This is the way things were for almost a century. Over the last few decades, crowns got larger, first to accommodate suspension forks, and later carbon forks, rendering the tools that push them out from below obsolete.

All that matters is that the crown seat diameter is adequate to make a press fit except for the split crown centering cones used with some cartridge bearing headsets.