Hvergelmir

Hi all,

I recently picked up a full RX-100 aluminium Batavus bike. Unfortunately the handlebars are too low and too forward to me. Since I need to change the stem, I thought I'd to a threaded (quill) to threadless conversion while I'm at it.

So, I thought I needed the following:

BBB Ahead Extender to give the height a little boost and convert to threadless at the same time;
A short A-head stem (generic).

I measured the diameter of the current stem and it's a 1" quill. Would these two items be enough, or do you really need those spacer rings they sell separately?

I've attached a picture of the current stem (which is way too long for my comfort ).



Any help is welcome!
Cheers

DiabloScott

That extender goes inside your current threaded headset, and then you get an external steerer clamp stem that fits on it. No, you don't need spacers.


"Threadless stem" is a misnomer, and you're not converting your headset to a threadless headset.

Hvergelmir

Thanks for the quick response. I wasn't thinking it would magically unthread my headset but I probably described it wrong, haha.

So - long story short, I get the BBB extender and the stem and I'm good to go? The spacers are purely there for looks? Thanks again!

DiabloScott

Yeah, that's all you need.

I'm just pedantic, almost everybody calls them threadless stems; they were invented to be used on bikes with threadless headsets. But you're not really doing a "threadless conversion", that's all.

Spacers are necessary on actual threadless systems so the headset can be adjusted, on an adapter like you're thinking they would serve no purpose.

headloss 

A threaded-to-threadless conversion would require that you change the headset as well as the fork... you aren't doing that. You are just using an adapter, which is still a quill stem, but with the ability to use a clamping stem that is designed for use with a threadless system.

Since you are still using a threaded/quill set up (albeit, with an adapter), there is no need for spacers. The spacers are required to set the preload when using the stem in conjunction with a thread-less fork, a fork that you don't have.

Hvergelmir

Thanks for the useful info, all!

BTW - there's difference between pedantic and precise, I think you were just being precise Diabloscott!

Off to order my new stuff now - Can't wait to hit the road!!!

DiabloScott

Make sure you order a stem with a bar clamp diameter that matches your handlebar.

Hvergelmir

Thanks for the heads-up; current clamp is not the pinch type but the removable faceplate type, so it will probably be ISO spec. But I'll go measure just to be sure

fietsbob

Most basic.. there is an aluminum piece machined to have a wedge in the bottom same as the stem you have, (7/8" or 1")

But, it's machined to be round and the top is the 1.125" so you just fit the threadless stem of your choice there.

the BHP 20 in 1st link, is for a 22.2mm (7/8") quill stems , the fork OD is 1" (1" headset 32mm wrench)

the BHP 21 is for an oversize threaded headset and as a stem riser* for threadless steerers .
(* I have one used for that)

and threaded forks with a 1" ID, and a 9/8" OD headset adjustment uses a 36mm wrench..