Why threadless stems? And five ways to raise your bars
September 18th 2019
In the past twenty years, the way handlebars are attached has changed completely, affecting how you customize your bike to fit your needs. We’ve gone from “quill stems” to “threadless stems.” Here’s why that change to threadless stems was so popular and how it helps you customize your bike fit to your needs.
Didn’t the old way work great? Why change?
Raising your handlebars used to be so easy decades ago back when we had what were called quill stems. You just loosened the big nut on top of your stem, lifted up your bars, and tightened the stem nut again. Easy peasy…if you happened to be carrying a big wrench with you, which never happened.
And finally, there was the weight issue. This whole design depended upon a long stem fitting inside a steel fork with a threaded top, and two big nuts at the top that turned against each other (each with its own wrench, since you’re turning both at the same time). Now you’re carrying two wrenches.
Put it all together, and you have a maintenance-intensive, complex way to attach your handlebars to your bike. But it had always been done that way, and every company followed the same approach, so who’s going to change an entire market?
Threadless stems, thanks to a biker and an office chair.
John Rader was a mountain biker with a machine shop and an annoyance. Mountain bikes were too heavy, and the tools to keep bars and fork secure in rough riding made the problem worse.
Somebody had to do something revolutionary, so he rethought everything about the fork and stem relationship. Those heavy and temperamental fork nuts were going away, so there was no need for the fork to be threaded anymore (or even steel). The steerer tube of the fork would keep going up past the frame, and a shorter stem would clamp to the outside of that.
There wasn’t a good way yet to raise the bars, but high bars weren’t as important for mountain bikers. And he hadn’t yet perfected how to provide the downward force needed to pull up on the fork and hold the fork on super-securely, but that was a detail for later. First, he needed to take his idea to a component manufacturer.
At the 1990 UCI World Championship, John got 30 seconds with a very busy sales manager at Dia-Compe–just enough time to demonstrate how to remove and replace a fork with just a hex wrench. That wasn’t much time, but the capability without big wrenches was eye-opening.
John had done the impossible, and got a call-back for a more comprehensive demo in an office…where the lack of downward compression soon became an issue. During the demo, his fork fell off and one part rolled under an office chair–a rolling chair that connected to its wheelset using a star nut.
This was the missing piece of the puzzle! A star nut inserted inside a bike fork provides something to pull up against, compressing the entire assembly together for a snug, reliable fit. And with that, the threadless stem was born.
Five ways to adjust your bar height with a threadless stem.
Once you understand the threadless stem concept, and the importance of that bolt on top, you can make all sorts of changes to make your bars the height you want. Here are five strategies.
1. MOVE YOUR SPACERS.
Spacers are rings in the area of the stem, usually made of aluminum or carbon. As long as your top cap can compress the assembly, you can move the rings above or below your stem–above to lower your stem, below to raise it.
2. FLIP YOUR STEM.
This is often done with stems that have a mild rise to them, such as 5 or 6 degrees. Serious racers will sometimes invert their stems for lower bars and a more aerodynamic ride. Or maybe because other racers are doing it.
3. REPLACE YOUR STEM.
If you decide to get a different stem, you’ll find there are a range of options available.
A short stem. A short stem doesn’t raise your bars, but by shortening the distance between hips and hands, it raises your upper body. (You can also do that by moving your seat forward).
An angled stem. Angled stems keep the steerer tube clamping point in the same place, but raise the handlebar clamp.
An adjustable-height stem. This is like an angled stem that you can experiment with to get your perfect combination of height and reach.
A THINstem. This threadless stem provides only about one inch of lift. Primarily, it does something else, allowing your bike to fold flat to fit against walls, so you can store a bike conveniently in a hallway or crowded garage.
4. REPLACE YOUR HANDLEBARS WITH RISER BARS.
Riser bars can add two inches or more to your bar height, or bring your bars more toward your hips for a more upright ride.
5. ADD A STEM EXTENDER.
A stem extender can raise your bars five or six inches to a completely different type of ride–more upright, and less opportunity for the upper body to help with steep climbs and fast descents. A bike with this handlebar arrangement is most similar to the “Dutch style” of riding (where there are fewer hills) or the high bar/low frame combination found on folding bikes with smaller wheels.
Adding a stem extender is conceptually easy–just extend the steerer tube of the fork higher with this attachment. But in practice, it typically requires swapping out the shifter and brake cables and housing with longer replacements. If you choose this approach, we suggest having a bike shop or a veteran rider do it.
Ready to customize a bike?
So now you know at least five ways to make your bike fit you better. And these techniques work with any threadless-stem bike.
One question we often get is . . . can you make these modifications to the folding, full-size CHANGE bikes you sell?
We can and do. It’s a couple of extra steps, and we might ask you to have a recommended part sent to us, but all the options except stem extender can be done for free on any bike that leaves our shop. (We install stem extenders too, but it requires additional supplies and shop time.)
Just as importantly, most of these updates are tweaks that you can easily make at home at any time. To see a stem swap-out in action, just look at this video.
Enjoy making your bike yours!
For more details on the origin of the threadless stem, see cyclingtips.com