Negotiating Headset Standards

Rockbottom

Rockbottom

Active Member
Looking to replace my lower headset bearings and I haven’t been able to find a proper fitting replacement. It’s a standard 52mm length, however the depth is 8mm. Any info on where I can find bearings in these dimensions? Headset brand is Tange Seike. Company is overseas and doesn’t seem to sell direct
 
Rockbottom said:
Looking to replace my lower headset bearings and I haven’t been able to find a proper fitting replacement. It’s a standard 52mm length, however the depth is 8mm. Any info on where I can find bearings in these dimensions? Headset brand is Tange Seike. Company is overseas and doesn’t seem to sell direct
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Read this first to get a better understanding of the headset bearings sizing and types.

https://cyclingtips.com/2021/06/how-to-measure-sealed-headset-bearing-sizes/

and this

https://www.parktool.com/blog/repair-help/headset-standards

52mm is most certainly the bearing external diameter which would make it an integrated lower headset (IS52), but that doesn't match the 8 mm if that is the height of the bearing. Are you sure it's not 51.8mm ? That would match a 40x51.8.

I will be assuming that you have a tapered 1.5" to 1.125" fork steerer tube so the internal diameter of the bearing race is going to be 40mm.

Can you read the bearing specs on the side of the bearings? It should say something like 40x51.8x8 mm 36/45 where

40 is the internal race diameter
51.8 is the external diameter
36 is the internal race angle (the one that touches the crown race)
45 is the external angle (the one that touches the bearing cup

If you don't have a caliper to correctly measure the bearing I wouldn't venture too much into guessing the correct size if you can't read the specs on the bearing and go to a bike shops.
 
Also.

What bike frame (year/make/model) is it?

Maybe a picture of the setup.
 
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So the bike is a 2017 Intense Tracer. The headset that the bike came with was a Tange Seiki Technoglide 1.5cb (non threaded). The lower bearing measurements that needs to be replaced are 52mm OD, 40mm ID and 8mm thickness. I have a tapered fork going from 1.5” to 1 1/8” which is standard. Company is from Japan and doesn’t sell direct. Cant find this headset for sale anywhere online or local. Very unusual to have lower headset bearings 8mm thick
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The angle at the cup looks like it could be 45deg, is the one at the crown race 45 or 36? The first link I posted shows how to determine that. Either way that sounds like a weird bearing to source, could your replace it with a external cup lower headset from a more easily available manufacturer, such as Cane CCreek or Wolftooth? It may just cost you about the same as replacing just that odd size bearing. Is that the original headset that came from the bike? The intense manual says the headset should be a Cane Creek 40.
 
serviceguy said:
The angle at the cup looks like it could be 45deg, is the one at the crown race 45 or 36? The first link I posted shows how to determine that. Either way that sounds like a weird bearing to source, could your replace it with a external cup lower headset from a more easily available manufacturer, such as Cane CCreek or Wolftooth? It may just cost you about the same as replacing just that odd size bearing. Is that the original headset that came from the bike? The intense manual says the headset should be a Cane Creek 40.
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The angle at the cup I believe is 45. It is certainly an unusual bearing to replace. This is the original headset that came with the bike

I agree that the best option at this point would be replacing the lower headset with a cane creek that houses a standard 6.5mm width bearing.

Thanks so much for all the info and resources you provided!
 
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