| A bike stem is the first point of contact from the | | | | clamp. Stem length can affect the responsiveness of |
| bicycle to the rider. In other words, it connects the bike | | | | the bicycle. A longer stem will cause slower bike |
| to the rider. Your choice of stem will affect the way | | | | response, while a shorter stem will react much more |
| your bicycle handles and the way your upper body | | | | quickly. |
| feels the road. While being one of the most important | | | | Stem rise/drop |
| bike parts for comfort and handling, it is also very | | | | Rise and drop are measured by the degree of |
| customizable and upgradeable. | | | | difference from 90 degrees from the steerer tube. |
| When purchasing a stem, you should consider several | | | | Quill stems are set with a positive or negative (rise or |
| factors. First you must determine headset type | | | | drop) or a zero degree rise. A threadless stem is |
| (threadless or quill). Then you must match it to a | | | | measured from 90 and can be flipped to give an equal |
| steerer tube diameter and a handlebar diameter. Finally, | | | | rise or drop, depending on orientation. For example, a |
| you must decide what length and how much rise or | | | | threadless stem with a 17-degree rise will have a |
| drop you want your bike stem to give you. Once you | | | | 73-degree drop (90-17=73). |
| have decided on those characteristics, you must | | | | Road stems for racing bikes are typically in the drop |
| decide on the material you'd like and consider its price. | | | | position because this gives the rider a dropped and |
| Stem type | | | | stretched out stance, while MTB and recreational bikes |
| The two main types of bike stems are "threadless" | | | | typically have a rise orientation to allow the rider a |
| and "quill." The type of stem required is determined by | | | | more comfortable upright position. |
| the headset and fork installed on your bicycle--either | | | | Stem material |
| threaded or threadless. Once you have determined | | | | The vast majority of bike stems on the market are |
| which headset style your bicycle requires, you must | | | | made from an aluminum alloy or from carbon fiber. |
| determine the different compatibility factors: steerer | | | | Some stems are built with an alloy structure wrapped |
| tube diameter and handlebar diameter. | | | | in carbon fiber for aesthetic and comfort reasons. |
| Steerer tube diameter | | | | Alloy stems are typically more affordable than the |
| Stems attach to the bike via the steerer tube. | | | | carbon variety, though some high-end aluminum stems |
| Threadless stems clamp around the steerer, while quill | | | | made of the highest grade alloys can be lighter and |
| stems use compression to attach to the inside of the | | | | more responsive than their carbon counterparts, |
| steerer. | | | | making them cost considerably more than the most |
| * Threadless Threadless headsets and forks come in | | | | affordable stems on the market. |
| four standard sizes: 1-inch, 1-1/8-inch, 1-1/4-inch and 1-1 | | | | Carbon stems are built for weight and comfort on the |
| 2-inch. These sizes correspond to matching stem | | | | bike. Road vibrations travel up the bike, through the |
| sizes. 1-1/8-inch headsets are the current leader in the | | | | fork and stem and handlebars into the rider's hands. |
| headset race. However, with new trends always | | | | Carbon fiber has great vibration-dampening properties |
| surfacing and old trends always resurging, this could | | | | and aids in removing a large part of this "road static." In |
| change in the future. | | | | order to make the carbon strong enough to be a safe |
| * Quill Threaded headsets come in 1-inch, 1-1/8-inch and | | | | stem material, they overbuild it to add strength. This is |
| 1-1/4-inch sizes with corresponding quill stems sized | | | | why the highest quality alloy stems can be lighter and |
| down for the internal diameter of the fork's steerer | | | | stronger than many carbon versions. Some boutique |
| tube. 1-inch threaded headsets were the industry | | | | bicycle companies offer titanium stems that have their |
| standard for decades and remain very popular in the | | | | own benefits. They are comfortable, look great with a |
| vintage and retro bike world. They remain the most | | | | Ti bike and are lighter than the less expensive alloy |
| widely used and readily available. | | | | versions. |
| Handlebar diameter | | | | Stem price |
| Handlebars come in many shapes and sizes. It is very | | | | Stem price is determined by several factors, namely |
| important that your stem's handlebar clamp be | | | | material and weight. It's easy to make a cheap alloy |
| compatible with your handlebar. Different brands have | | | | stem and put it on the market. This stem is going to be |
| minor variations to the standard sizes. Typical HB | | | | heavy and lack aesthetic value. Likewise, it is easy to |
| Clamp sizes are 25.4mm (ISO and MTB), 26.0mm | | | | build an inexpensive carbon stem. This stem will offer |
| (road standard) and 31.8mm (oversized road and | | | | little benefit. It will be built with such thick carbon that it |
| MTB). | | | | will transfer more road static than other carbon models |
| Now you have the two main factors down. Once you | | | | and will be heavier than even moderately priced alloy |
| determine the clamp size for a threadless stem or the | | | | stems. |
| steerer tube inner diameter for the quill stem and the | | | | All bike stems, when properly chosen, are going to |
| appropriate clamp size for you handlebars, you can | | | | function identically. They are going to be safe. They will |
| decide what length and drop are necessary for your | | | | hold your bars, your steerer tube and will steer your |
| ideal bike fit. You can then decide what material and | | | | bike. When you look at the upper price range, you are |
| price to look for in your stem. Stem length and rise | | | | looking at more engineering and more research money |
| drop are determined based upon fit requirements. | | | | put into that stem that the company is trying to recoup. |
| Different types of bicycles and riding styles require | | | | Carbon and high-end alloy stems are going to top the |
| different stem dimensions. Your stem purchase should | | | | charts alongside titanium, with cheap carbon and other |
| be based on your required fit, not the other way | | | | alloy stems filling in the lower price ranges. |
| around. | | | | Some extra tips for choosing the right stem |
| Stem length | | | | When using Aero-bars, cruiser bars or others that |
| Length or reach is the horizontal measurement of your | | | | place added torque on the bar, be sure to use a stem |
| bike stem. It is measured from the center of your | | | | that is able to withstand the increased torque. Most quill |
| steer tube to the center of your handlebar clamp along | | | | stems and some threadless stems secure the |
| the central axis of your stem. Stem length typically | | | | handlebar with a single binder bolt securing the lower |
| ranges from 60mm to 150mm with some outliers in the | | | | portion of a wrap-around bar clamp. This requires you |
| extremes. | | | | to remove any shifters or levers and grips or bar tape |
| Road stems for racing bikes are typically on the longer | | | | from at least one side of your bar to do a stem swap. |
| side of the scale, giving the rider a more stretched-out | | | | More common today is a detachable faceplate with |
| riding position, with mountain bike stems and | | | | 1-4 securing bolts. The faceplate can be removed, |
| recreational bicycle stems on the shorter side, providing | | | | alloying the bar to fall free. This is a much more |
| a more upright position. BMX stems are an exception | | | | convenient setup that is just as secure as the older |
| and are in a class by themselves. Quill stems are | | | | version, though less aesthetically pleasing in some |
| generally measured perpendicularly from the center line | | | | people's eyes. |
| of the steerer tube to the center of the handlebar | | | | |