Classic & Vintage - What is the stem size for the Trek 660?

I have a 1989 660 and want to replace the threadless stem. I measured the diameter at a little under an inch. I'm sure it is a standard size, but don't know what it is for reference purposes.

Thanks

RFC

I have a 1989 660 and want to replace the threadless stem. I measured the diameter at a little under an inch. I'm sure it is a standard size, but don't know what it is for reference purposes.

Thanks

RFC

They did not come with a threadless stem.

I'll bet someone either 1.) Replaced the original fork or 2.) stuck a stem adapter into the threaded steering tube (22.2 mm) with a nominal 1" clamp diameter. Maybe just to modernize the look of the bike. Or. perhaps they crashed the bike and wrecked the fork?

My apologies. I was wrong. It is not a threaded stem. It is the typical stem that came with bikes of that era. That is, the one piece stem is inserted into the headset and then tightened by way of the bolt located at the elbow of the stem.

My apologies. I was wrong. It is not a threaded stem. It is the typical stem that came with bikes of that era. That is, the one piece stem is inserted into the headset and then tightened by way of the bolt located at the elbow of the stem.

Whoa there. :p I think you do have a threaded steerer tube, which takes a quill stem, and if so, the size is a 1" stem, which means the part that inserts into the steerer tube is 7/8" in diameter, often listed as 22.2mm. The "one inch" name comes from the steerer tube having an outside diameter of 1." The inside diameter of the steerer tube is 7/8" (22.2mm), which matches the stem.

You have a threaded fork and headset with a "quill" stem. Look for a standard 1" quill for replacement.

Any standard "1 in." (actually 22.2mm) quill stem will work. Just for example, I have a 3ttt stem just like this one on my '89 660.

http://img.inkfrog.com/pix/coronadelmar/3TTT_Synthesis_120mm_Quill_Stem_02.JPG

Cool. In that case the size would be 22.2 mm. This was the standard size used on all forks worldwide with the exception of French bikes).

But, since this came to mind, you actually could buy an adapter extension for around $10 and then use more modern threadless stems which are now available in many sizes and different styles. Juat a thought. Personally I prefer the older look, but there is that option, and I've seen a lot of slick looking bikes built up with that simple and inexpensive modification. :)

Here is what the part looks like. Voila! Instant threadless fork.

http://www.lickbike.com/lickimages/1089.gif

All good advice. Thanks

I did the threadless adapter on my Trek. I do like the quill stem look, but I wanted a new handlebar and it was just easier going with the adapter. I also went STI 9 speed, 700c wheels and dual pivot brakes. I did keep the frame though.

OK, now that that's settled, where can I get a black quill stem?

Thanks

RFC