What is this stem?
 

What is this stem? I tried putting a normal stem on the fork but then then the fork is too short. What are my best options for cable maintenance if I were to stick this stem? Are those 4 bolts meant for anything special like some kind of a proprietary tri-bar mount? Are there [road/aero] handlebars that have center cutouts/drillings to allow for internal routing directly through a hollow-design stem? Thanks for any help!


https://cimg0.ibsrv.net/gimg/bikefor...88c80e4f6b.jpg
https://cimg1.ibsrv.net/gimg/bikefor...972c6f4841.jpg
https://cimg2.ibsrv.net/gimg/bikefor...2c8f676ec5.jpg

:popcorn:

Is this a new bike you bought without knowing anything about it?

Looks like it's a proprietary stem for an aero frame, but you tell us.

Doesn't look like it. It looks like they're to clamp the handlebars in place, just like a normal stem faceplate... but more aero.

There are some handlebars that have cutouts for internal wiring, passing through the stem, but they're few and far between. PRO (Shimano) has one or two and there may be a few others that are meant to be a model-specific (usually areo bikes, from the likes of Trek, Specialized, etc), but that's about it.

Looks like an adjustable-angle stem with an upward-facing, rather than forward-facing, four-bolt bar clamp. Not sure what's going on with the top cap - in the second pic there's what looks like a slot, but I think that's just a reflection - no sign in pic#3. In any case, there appears to be a small rubber nub in the cap center - probably pry this off to expose the cap bolt. Looks like two steerer clamp bolts at the rear of the stem. Apart from the fact that it appears matched to the frame and the adjustable angle, it looks like it functions like a standard threadless stem. Are there any extra holes in the bars or stem to suggest that cable routing is unusual (the holes in the top of the stem and at the front of the top tube are suggestive of something). However, the tape patch on the side of the head tube in pic#3 looks like it's there to prevent cable rub.

What are those holes shown in the second picture behind the top cap? They look like cable holes to route the cables internally.

Fork is too short? Certainly you mean the steerer tube is too short.

What is a "normal" stem? Pista? The old "7" style stem with wedge nut?

fify, the popcorn does NOT need a trailing semicolon for unknown reasons

That’s actually a colon. You are welcome.

Correct. Thanks.

Back on topic, the answer to the question “what type of stem is this” my best answer is I don’t know but it sure is ugly.

Oops. See I made it myself and obviously had no idea what I was doing.

That's an Aliexpress no-namer stem on an Aliexpress no-namer CF frame.

https://cimg0.ibsrv.net/gimg/bikefor...e695bdb488.jpg


SO yeah, uhhh.. whatever that frame is stickered as now, it probably ain't that.