Stems

The stem on a bike connects the handlebars and steerer tube. The shape, the length and the angle of the stem define both the handling of the bike and the seating position of the rider. There are roughly two different types of stems: quill stems and sahead stem. We generally use steerer stems on classic bicycles with forks with a 1" threaded steerer tube and threaded headset. The stems sits inside the steerer tube and are fastened with a clamping or expanding wedge. Threadless stems are now standard straight in the area of ​​sporty bicycles. In contrast to steerer tube stems, Ahead stems clamp on the outside of the steerer tube. The inner diameter of the stem must correspond to the outer diameter of the steerer tube. With a few exceptions, the dimension is 1 1/8". For forks and frames with 1 1/8" Ahead systems that use Ahead stems HERE you will find a wide selection of possible headsets.

The stem on the bike makes the connection between the handlebar and steerer tube and must be compatible with these two components. Whether your bike needs a threadless Ahead stem or a classic threaded stem depends on the type of bicycle frame. In addition, the stem depends on the stem clamping as well as the handlebar clamping: The stem must fit the diameter of the stem and the bicycle handlebar. Manufacturers of stems specify for stems the length, the angle of inclination and the clamping diameter, which refers to the diameter of the handlebar. The stem on the bike not only holds the handlebars in place, but also influences your sitting position on the bike depending on the height, length or angle of inclination.

The stem on the bike - An essential adjusting screw for a more efficient seating position: With no other part on your bike you influence the seating position as much as with the stem. Therefore, there are stems in many different lengths and angles. The stem length is always measured from the center of the handlebar clamp to the center of the stem clamp. The angle always refers to the horizontal. If the stem points upwards, the angle is given positively, if it bends downwards, it is negative.

The different clamping diameters: The diameter of the bicycle handlebars is not the same for every bike. Accordingly, there are different dimensions for the handlebar clamping on the stem. So when buying a stem, make sure that the handlebar clamp fits your bike or bike handlebar. Established standard dimensions for different bike types help you with orientation:

• 22.2mm: for older mountain bikes, BMX

• 25.4mm: ISO standard, for almost all trekking handlebars & Dutch bikes

• 26mm: common on road bike handlebars

• 31.8mm: oversize for racing handlebars, trekking bike & MTB

• 35mm: oversize for mountain bikes

Different types of stems

A-Head Stems: What is an Ahead stem? This term is a trademarked brand name of a particular type of stem that is mounted directly on the fork tube. Its advantages are its light weight and torsional rigidity. Height adjustment of AHEAD stems is possible through spacers (spacers).

Quill Stems: A stem with threaded control set is found predominantly still on older bicycles. The stem is here from above in the steerer tube and wedges there thanks to spreading or slanted cone. Accordingly, it is important that the diameter of the stem shaft fits the inner diameter of the steerer tube. Advantageous at the stem stem is that it can be continuously adjusted in height up to the marking of the maximum height. With a shaft stem, you can easily adjust the handlebar height and thus the seating position with an Allen wrench. In addition, the headset does not have to be loosened when disassembling the stem.

Pay attention to the material of the stem and fork of the bike: stems are either made of aluminum or carbon. Aluminum is slightly heavier, but less sensitive than carbon. Depending on the material, you should grease the threads before mounting: For pure aluminum components, use common assembly paste, but for carbon components and aluminum-carbon combinations, use special carbon assembly paste.

The stem on your bike, together with the geometry of your frame, greatly influences the handling and ride of your bike. The geometry of the stem (length, angle) allows your bike to be adapted to a high degree to your individual needs, preferences or necessities. The geometry of the stem in combination with the handlebar used determine the posture of the rider on the bike from very sporty aerodynamic overstretched to very comfortable upright. The choice of the right length depends on the size or geometry of your frame and your individual physical requirements (torso and arm length). We at BIKE PUNK offer you various stems of the brands BLB, CINELLI, Thomson, DEDA Elementi and Dia Compe in different geometries, colors and qualities.

If you have questions about our range of bicycle stems, are not sure whether or which are compatible with your bike or want a general advice, contact us via phone or email or just visit us in our BIKE PUNK SHOWROOM in Berlin-Kreuzberg! If we do not have a certain product in stock, we will try to get it for you in a timely manner. We are happy to advise and accompany you on all topics related to your bike. For the latest products, inspiration and information follow us on Instagram!