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Old 05-13-12, 10:27 AM   #1
hanvyj
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Need replacement fork - what is this on the steerer?

My steerer seems to have a wider diameter around the base (the shiny bit, not the headset):



I need to replace it but the new fork has a lot more play in it compared to the old one, it is the same diameter but doesn't have this little lip at the bottom that slightly increases the diameter of the steerer. Is this normal, or do I need a different one? Thanks for any advice.
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Old 05-13-12, 10:43 AM   #2
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The shiny par is just part of the fork crown.

did you put a Crown Bearing Race on the new fork or is still on the old one (the black part) did you get the correct size steerer?

there is a tool for removing it and your local bike shop likely has one. they also have the slide hammer tool to reinstall it on the new fork.
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Old 05-13-12, 11:17 AM   #3
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The black ring of the bottom of the headset is still there.
but if you replace the headset when you replace the fork,
then that will be fine.. pop the races out of the frame,
and stack it all together .. on the old fork.
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Old 05-13-12, 12:02 PM   #4
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I'm not sure what you mean by stack it all together?

I took the black ring off (the racer?) and it measures 30mm inside diameter. The rest of the steerer measures about 28mm. When I put the old racer on the new fork, its 2mm too big. So I need a 30mm steerer? Won't it not fit at the top if its the same length all the way down?
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Old 05-13-12, 12:54 PM   #5
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What's on the fork is the crown race, which is part of the headset. If you buy the proper size fork to replace the old one, then your crown race will fit on the fork and it can be reused.

Here's a link to repair info.

http://sheldonbrown.com/headsets.html

http://www.parktool.com/blog/repair-...dset-standards

Last edited by DaveSSS; 05-13-12 at 12:58 PM.
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Old 05-13-12, 01:31 PM   #6
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I don't think a 28mm to 30mm fork exists. I guess I am going to have to change the headset to use a standard 1 1/8 steerer instead of this non-standard 30mm one?

The shiney metal bit that makes it 30mm diameter at the bottom for the 30mm crown race is machined into the metal i think, its not something that can be taken off...
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Old 05-13-12, 01:39 PM   #7
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Quote:
Originally Posted by hanvyj View Post
I don't think a 28mm to 30mm fork exists. I guess I am going to have to change the headset to use a standard 1 1/8 steerer instead of this non-standard 30mm one?

The shiney metal bit that makes it 30mm diameter at the bottom for the 30mm crown race is machined into the metal i think, its not something that can be taken off...
If you'd read the info at the links I provided, you would see that a standard 1-1/8 inch (28.6mm) steering tube has a 30mm diameter crown race ID. All forks have an enlarged diameter at the bottom of the steering tube, where the crown race presses onto the tube. There is nothing that needs to be removed from the old fork, other than the black crown race, shown in your picture.

All you need is a fork with a standard 1-1/8 inch steering tube.

Last edited by DaveSSS; 05-13-12 at 01:53 PM.
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Old 05-13-12, 01:40 PM   #8
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I've never heard of a "30 mm steerer". I think what you have is a 1 1/8 fork with a crown collar that was not machined to specs. Park makes a special tool for "facing" the collar to make it fit a standard 1 1/8" crown race. Talk to your LBS. Some shop in your area will probably have the correct tool for fixing your problem.
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Old 05-13-12, 01:40 PM   #9
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Quote:
I'm not sure what you mean by stack it all together?
just put all the old parts from the original headset on the steerer tube
on the old fork, try to put them all in the same sequence as they were when on the bike
in the 1st place.. that is what I mean by stack.. like pancakes..

mechanics also use the term 'stack height', when forks were threaded,
you had to be concerned about how much thread was left to screw the last piece on top.

Then you needed the dimension of how much it required. stack height..
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Old 05-13-12, 01:45 PM   #10
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I think you need to take everything to a bike shop.

fork crown races do come in different sizes but I don't think it is 28 and 30mm I believe it 26.4 and 27 or something like that. odds are your old fork was a 27 and the new one is a 26.4. You may need a new headset.

What kind of bike is this? why are we changing the fork?
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Old 05-13-12, 01:57 PM   #11
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I've never heard of a "30 mm steerer". I think what you have is a 1 1/8 fork with a crown collar that was not machined to specs. Park makes a special tool for "facing" the collar to make it fit a standard 1 1/8" crown race. Talk to your LBS. Some shop in your area will probably have the correct tool for fixing your problem.
I've had bad experiences with my local bike shops... But yes, its a 1 1/8 fork with some kind of non standard collar. As far as I can guess the manufacturer have put it in so I have to go to them to get a replacement...

Quote:
just put all the old parts from the original headset on the steerer tube
on the old fork, try to put them all in the same sequence as they were when on the bike
in the 1st place.. that is what I mean by stack.. like pancakes..

mechanics also use the term 'stack height', when forks were threaded,
you had to be concerned about how much thread was left to screw the last piece on top.

Then you needed the dimension of how much it required. stack height..
The old parts don't fit (at the bottom of the headset), they are 2mm too large (they fit fine on the top).

Quote:
I think you need to take everything to a bike shop.

fork crown races do come in different sizes but I don't think it is 28 and 30mm I believe it 26.4 and 27 or something like that. odds are your old fork was a 27 and the new one is a 26.4. You may need a new headset.

What kind of bike is this? why are we changing the fork?
There is no way my measurements are out by 2mm :/

28mm is about 1 1/8'' so that's a standard steerer, I can measure the existing headset race diameter to within half a mm with a ruler, and I know its just a few mm larger because I can put it on an existing standard 1 1/8'' fork and it has a few mm play in it.

I think a new headset should solve my problems. A standard FSA headset should fit on my roughly 44mm inside diameter head tube and fit a standard 1 1/8 fork and racer.

My bike is an old model (pretty much same components I believe though) of this: http://www.edinburghbicycle.com/products/revolution-continental-sport-11?bct=browse/bicycles/road-bikes

I am replacing the fork because a car drove into it, and it was carbon. There is a hairline crack running around the the blades and I don't want it to break while cycling.

Last edited by hanvyj; 05-13-12 at 02:05 PM.
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Old 05-13-12, 02:20 PM   #12
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Read again DaveSSS's posts.
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Old 05-13-12, 02:42 PM   #13
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Can you post a picture of your new fork with the crown race from your old fork on it? That would really help us determine if the crown race does or does not fit correctly. It should have to be pressed EXTREMELY tightly down onto that shiny collar.
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Old 05-13-12, 02:47 PM   #14
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Originally Posted by Seb71 View Post
Read again DaveSSS's posts.
Sorry, there are 4,500 words in that link...

So I have this?

[TABLE="width: 273"]
[TR]
[TD]Size/Stem diameter
Steerer O.D.

[/TD]
[TD]Crown race
Inside diameter

[/TD]
[TD]Frame Cup
Outside Diameter

[/TD]
[TD]Notes
[/TD]
[/TR]
[TR]
[TD]1 1/8" (28.6 mm)
[/TD]
[TD]30.0 mm
[/TD]
[TD]34.0 mm
[/TD]
[TD]Most newer mountain bikes use this size.
[/TD]
[/TR]
[/TABLE]

How on earth can a 30mm crown race fit on a 28.6mm steerer?
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Old 05-13-12, 02:51 PM   #15
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Quote:
Originally Posted by hanvyj View Post
How on earth can a 30mm crown race fit on a 28.6mm steerer?
Like this:
Quote:
Originally Posted by DaveSSS View Post
If you'd read the info at the links I provided, you would see that a standard 1-1/8 inch (28.6mm) steering tube has a 30mm diameter crown race ID. All forks have an enlarged diameter at the bottom of the steering tube, where the crown race presses onto the tube. There is nothing that needs to be removed from the old fork, other than the black crown race, shown in your picture.

All you need is a fork with a standard 1-1/8 inch steering tube.
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Old 05-13-12, 03:00 PM   #16
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Can you post a picture of your new fork with the crown race from your old fork on it? That would really help us determine if the crown race does or does not fit correctly. It should have to be pressed EXTREMELY tightly down onto that shiny collar.
This is the new fork, with the old crown race, showing the difference in diameter:


This the old fork, with the old crown race on, showing the diameter is the same (except at the base)


This is the new fork with the old and new crown racer - notice the gap. The shiney metal machined part on the old fork made it the 30mm required to fir the old crown race:
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Old 05-13-12, 03:02 PM   #17
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Ok, I see, so if I take the new forks crown race off it will have the extra diameter? I'll give that a go.

Edit: Can't get the damn thing off

Last edited by hanvyj; 05-13-12 at 03:06 PM.
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Old 05-13-12, 03:07 PM   #18
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It seems that the "new" fork is only new to you. It already has a crown race installed. You have to remove that in order to install your crown race.

Another thing to check is if the new fork has the same Axle to Crown Distance (ACD) as the old fork.
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Old 05-13-12, 03:13 PM   #19
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Originally Posted by Seb71 View Post
It seems that the "new" fork is only new to you. It already has a crown race installed. You have to remove that in order to install your crown race.

Another thing to check is if the new fork has the same Axle to Crown Distance (ACD) as the old fork.
Thanks, the bike shop spent 5 weeks "ordering" a fork and in the end gave me this one, which is an ex display
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Old 05-13-12, 03:27 PM   #20
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Hope you didn't pay "new" price for that, it's had brakes installed on it too.

If you're impatient like me, this is a job you can do at home with basic tools, but you need to be very careful; mangling the race means the bearings won't roll correctly, and then you really will need a new headset. I removed my old crown race by bracing the steer tube against the floor and using a flathead screwdriver and hammer to loosen the race a little on each side, alternating every 2-3 blows, until it fell off. Take your time and be careful not to scratch the machined wall with your screwdriver. [Edit: This may not work for you with your fork design]

Now, put the fork in the freezer and the race in the oven for about 20-30 minutes. Take them both out and if you move quickly enough, the race will slide right on. There are more detailed instructions, with the recommended oven temp and other tips, online somewhere.

Or, you know, bring it to a pro. Should be a quick and cheap job. In fact, I'd expect the shop you bought it from to do it for free for all the trouble they put you through.

Last edited by ecnewell; 05-13-12 at 03:31 PM.
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Old 05-13-12, 03:46 PM   #21
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Hope you didn't pay "new" price for that, it's had brakes installed on it too.

If you're impatient like me, this is a job you can do at home with basic tools, but you need to be very careful; mangling the race means the bearings won't roll correctly, and then you really will need a new headset. I removed my old crown race by bracing the steer tube against the floor and using a flathead screwdriver and hammer to loosen the race a little on each side, alternating every 2-3 blows, until it fell off. Take your time and be careful not to scratch the machined wall with your screwdriver. [Edit: This may not work for you with your fork design]

Now, put the fork in the freezer and the race in the oven for about 20-30 minutes. Take them both out and if you move quickly enough, the race will slide right on. There are more detailed instructions, with the recommended oven temp and other tips, online somewhere.

Or, you know, bring it to a pro. Should be a quick and cheap job. In fact, I'd expect the shop you bought it from to do it for free for all the trouble they put you through.
Thanks
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