Ill fitting 1 3/8 bearing - are there different types?

Discuss light weight issues concerning road bikes & parts.
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ave
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by ave

It's a chinese noname frame.

Somehow I don't think it's the correct bearing for this fork. It won't go further down even with torqued down headset.
The bearing should sit almost on the flat surface, no?
Image

It leaves an unsightly gap when installed into the frame.
Image

I do not know bearings. I measured this 37mm inside, 49mm outside, 7mm tall.
Are there different types with these main dimensions? I don't know anything about the angles.

I am hoping to somebody knowledgeable can help me with finding a solution?

As an alternative solution can sanding/grinding down the carbon bearing race a bit work?

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wheelbuilder
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by wheelbuilder

Yes. The bearing should be sitting down on that angled carbon race. Are you sure you are not putting the upper bearing on the fork by mistake? Is it a tapered fork? The chinese carbon frames sometimes have pretty severe tolerance issues.

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ave
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by ave

It's a tapered fork, yes. The bottom bearing is much bigger than the top one, so it's surely the "right" one.
I'll try to find a tapered fork in a bike shop somewhere to check where the bearing sits on that, but 1 3/8 is not too common size.

alcatraz
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by alcatraz

Maybe you need a bearing with an appropriate chamfer on the inner race.

Like in this picture.

Image

/a

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ave
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by ave

Of course it's chamfered. But what I'm wondering, maybe there are differently chamfered bearings with the same inside diameter of 37mm.

alcatraz
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by alcatraz

There are different angles on the chamfer. Probably it won't help you.

Maybe riding the frame for a short while will seat the bearing. (assuming the frame is new)

/a

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ave
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by ave

The best picture I could manage showing the gap between the molded race and the bearing.
Image

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ave
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by ave

Yes, I will try to ride it, to see if hitting potholes help. :)

alcatraz
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by alcatraz

Found this pic of some available sizes, maybe it helps.

Image

hambini
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by hambini

It looks like the ID is too small and possibly an issue with the chamfer angle. Are you sure it's the correct bearing size (forgetting the chamfer)

Hambini

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ave
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by ave

I am trying to source another bearing, also found a friend who has a similar fork, will check my bearing on his fork.

In general it's the right size. Outside diameter is perfect, and I didn't find any bearing with different inside diameter with the same outside diameter.

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ave
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by ave

Found a new bearing in a LBS. The bearing chamfer is obviously different. New one on the right.
Image

It fits the fork much better! (animated)
Image

But now the gap between the frame and the fork disappeared totally, if I torque down the headset, the fork won' turn. :(

I measured the new bearing to be 49/37/6.5, so its height is 0.5mm lower.
The new one marked to be 1-3/8" ACB 36 x 45

So I'd need either a 49x37x7 36/45, or a 49x37x6.5 45/45. Neither of them exist it seems! :D

glepore
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by glepore

Cysco Ti custom Campy SR mechanical (6.9);Cannondale SS Evo Di2 7970 (5.79); Willier Cento Uno Air Di2 9070 (7.0); C40 Mk2 DA 7800 ; Anvil Custom steel Etap;1996 Colnago Technos Record

alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

What about putting a thin shim under the new bearing?

Apart from the different chamfer, the new bearing looks shorter than the old one. If you could get the new chamfer but the same thickness you might be just right.

/a

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ave
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by ave

Yep, a thin shim would be great, I already asked a mechanic if it's possible to make one.

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