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switching from quill-type to the other kind?(6 posts)

switching from quill-type to the other kind?nyedid
Apr 13, 2002 10:33 PM
okay, so i (total newbie) got a great deal on a bike but it has a quill-type stem (not the kind where the stem goes around the entire steerer tube). i'm wondering what i would need to do to convert to that kind of stem. i'm pretty sure i'd have to get a new fork, but that's not a big deal. so if i got a new fork, what else would i have to do to convert? thanks! --namir
threadless stem conversion...C-40
Apr 14, 2002 4:55 AM
You can get an adapter that will allow you to use a threadless stem with your threaded headset and fork, but you get none of the advantages of the threadless design.

To make the full conversion you need a new fork (with the proper rake), a new headset and a new stem. The headset should come with a top cap and a "star-fangled nut" that are also required. If a fork with a carbon steering tube is purchased the fork will come with a special expanding plug that is used in place of the star-fangled nut.

Stem selection can be tricky. Quill stems are usually 73 degree which places the stem extension horizontal. The quill is used to raise and lower the stem height. The new threadless stems use spacers to raise and lower the stem. Threadless stems come in a variety of angles to help achieve the desired bar height. Most stems can also be flipped upside down to produce a greater rise. An 80 degree stem, for example can be flipped to produce a 100 degree angle. If this is done, the next longer size will be required to achieve the same horizontal reach.

Most threadless stems are also measured differently than quill stems. Threadless styles are often .5cm longer than the "same" size quill stem, due to the difference in measuring reference points. Older quill stems could be measured by laying a scale across the top, measuring from the center of the quill to the center of the bars. Try this with most of the new threadless types and the stem will measure longer than it's stated length (although their are exceptions).
more questions! help! advantages?nyedid
Apr 14, 2002 8:48 AM
what are the possible advantages of a threadless stem/headset? also, i wasn't clear on your response: the first line said "you can get an adapter that will allow you to use a threadless stem with your threaded headset and fork, but you get none of the advantages of the threadless design." does this mean: a) i'm stuck with a threaded setup no matter what i do, even if i get an entirely new threadless headset and fork? or b) i'm only stuck without the advantages of a threadless design IF i use the adapter?
more questions! help! advantages?LC
Apr 14, 2002 9:59 AM
The conversion allows you to use the current fork. The advantage of changing everything is a slight decrease in overall weight, but with the conversion the weight will be about the same. There is a disadvantage to all this too, less adjustable and expensive for very little gain.
advantages...C-40
Apr 14, 2002 2:16 PM
Threadless headsets adjust the bearings with a slight load from the top cap. Once the stem is clamped in place, the adjustment is unlikely to change. Threaded headsets use the threaded top bearing race and a locknut to adjust and hold the setting. The threadless type is much easier to get right.

Threadless stem are also ligher.

The adapter I spoke of just sticks into the steering tube like a quill stem, leaving a 1" post to clamp a threadless stem on. It really just changes the stem into a quill type.
IMO, advantages are more theoretical than real...cory
Apr 15, 2002 7:34 AM
There are some paper advantages to threadless (offset, in my opinion, by the lack of easy adjustability). In practice, though, many of us have ridden tens of thousands of miles with plain old 1-inch threaded headsets and quill stems with no problems at all. It's just not an upgrade that makes any sense, unless maybe you have to replace a fork and headset anyway.