Headset Question

[ALLMTB]

Hello all!

 

I need replace my headset and I need some advice regarding the different measurements.

 

The headset I need is a Tapered 1.5" - 1 1/8" semi integrated, that part I understand.

But can someone please explain what the following numbers mean?:

 

OD 50/61mm / ID 44/55mm

 

I guess OD and and ID stand for outer and inner diameter, but why are there two number for OD and ID?

 

Also, which headset do you use?

The current headset which is fitted to the bike has sealed bearing at the top but an old school/cheap open jobbie at the bottom which lets in a lot of dirt and water.

I would like one with a sealed bearing at the bottom as well, but my budget does not allow for Hope or Chris King bling.

 

 

Please advise.

 

Thanx