Headset lower Bearing Type!

flycop2000

Hi,
I need to replace the Headset bottom bearing on my Merlin Evolution bike but unfortunately I can't get any info off the old bearing as its tarnished too much. I used an electronic caliper to get dimensions of 40 x 51.96 x 7.98. there is also a outside 45deg chamfer and an unknown size chamfer on the inside.

I can get two different bearings with correct dimension but two different internal chamfers, 45 or 36 deg

Q1. Does it make any difference for the size of internal chamfer?
Q2. Would a 40 x 52 x 7 mm bearing be suitable as its easier to get this size.

Merlin cycles wee not much help as they could only sell me a complete head kit and didn't know what size of bearing they installed in their bikes!

8) 8)

keezx

1-All models are listed as 45x45, so most likely no problem
2-http://mbbearings.co.uk/catalog/index.php?main_page=product_info&products_id=975

flycop2000

Hi,
thanks for the advice but I should has mentioned in my previous post that it is "Merlin" the UK Lancashire based company and not the American one.

keezx

What is the relevance of Merlin in this case?
I advised only technical.

flycop2000

Hi Keezx,
I could not find the listed bearing sizes and Merlin themselves could not tell me the size when I spoke to them however I did see the US Merlin bearing size mentioned on web site.
where did you find the information?

keezx

Google is your friend....
If you take the fork out of the frame and you may determine the internal chamfer at the steerer. (cone)
36 or 45 should be recognized.;...

flycop2000

Cheers,
I'll post on how I get on.

flycop2000

Managed to get hold of a set square and check the internal angle, it's 45deg. Now, does anyone know if a 7mm bearing will make much of a difference or is it a case of fitting it and see if there is enough clearance between the fork and head tube?

wishitwasallflat

flycop2000 wrote:

Managed to get hold of a set square and check the internal angle, it's 45deg. Now, does anyone know if a 7mm bearing will make much of a difference or is it a case of fitting it and see if there is enough clearance between the fork and head tube?

I can't speak from direct experience of this frame but if the old bearing was 7.98 why are you thinking of 7mm and not 8mm? I would expect with a 7mm you would need at least three (or even four) 0.25mm spacers or surely it would bind?

keezx

Yep, either 8 mm or spacer(s).

flycop2000

It was easier and quicker to get a 7mm thick bearing locally. 8mm thick bearings don't seem to be as common in road bike headsets?
I will just have to get one over the internet and wait for it coming.

Thanks for all your help.

dj58

http://simplybearings.co.uk/shop/Bearin ... _info.html

flycop2000

Thanks for supplying the web link to simply bearings, but the bearing on their site is slightly different to the one I require, theirs has a 36deg x 45deg chamfer. The one I require has a 45 x 45 chamfer.

Found this site: http://rullabearings.com/

This has the bearing I require.