Stem adaptor for Klein Attitude 1990 - help needed

[Slingshot92]

Hi,

I would like to use a modern handlebar stem in my Klein Attitude 1990.

The original goose neck stem tube width is 31,8 mm. Since the sizes are mostly listed in inches I am a bit
confused what diameter stem adaptor should I use?

 

[Thias]

1990 Attitudes usually have the Mission control 1 stem. Don't throw it away if you have it! There are many Klein-lovers that will pay good money for those.
You wrote "goose neck" - that's a bit confusing. Do you have a pic?
This is what I would call goose neck:

And this is a 1990 Attitude with MC1

But I have to say that those Klein stems are non-standard. I don't think you will find anything that fits out of the box.

 

[Slingshot92]

Hi,

I would like to use a modern handlebar stem in my Klein Attitude 1990.

The original goose neck stem tube width is 31,8 mm. Since the sizes are mostly listed in inches I am a bit
confused what diameter stem adaptor should I use?

1 inch (in) = 25.4 millimeter (mm). The stem tube radius should be 31,8 mm.

 

[Slingshot92]

I have the original MC1 stem x 2. The original is broken and welded really badly. Another one is in very good condition
but it is not green. It is brushed aluminum color. The original Klein green color is very hard to get and to make it look original it would cost appr 150$ to paint it properly.

Another reason I would like to use a modern stem tube, stem and handlebar is that the original MC1 handlebars are extremely narrow.

Here's the original green (broken) version.

 

[Slingshot92]

I was thinking to use these.

 

[Slingshot92]

So, in other words I would need a threadless stem adapter, similar to this. The tube radius would need to be 31,8 mm
(similar to Klein MC1 tube).

 

[Thias]

Then I would suggest that you need a 3.2mm (wall thickness) reducing sleeve, if using a 1 1/8" adapter, as pictured above. The same type/principle as used for reducing seattubes.

I think you will have to ask some machine shop to turn it for you.

 

[Slingshot92]

Then I would suggest that you need a 3.2mm (wall thickness) reducing sleeve, if using a 1 1/8" adapter, as pictured above. The same type/principle as used for reducing seattubes.

I think you will have to ask some machine shop to turn it for you.

I believe that the easiest way is to make it. I have few very skillful machine shop contacts so I will take the original stem to them and ask them to make me the right radius tube for the stem. The only thing that bothers me a bit is that because this is very stress sensitive are normal aluminum tube might just be too weak. Stainless iron tube would be strong enough but a bit heavier. On the other hand, the part is quite small so the total weight gain is not so big.

 

[jonrock]

Re:

Hi,

I'm sure you can use a 1 1/4 quill stem?

Alternatively you could use inserts to make the bars wider.

They can be welded or glued in.

J

 

[Slingshot92]

Re:

Just ordered extender parts for the original MC1. Keeps the bike as authentic as possible this way.