A Guide to
Stems & Handlebars
Road bike stems are available in lengths from as little as 60mm up to a very long 130mm and beyond. Aside from length, you’ll also find that stems are available in a range of different angles, effectively altering the height of your handlebars. The same is true for mountain bike stems , except they are available in lengths much shorter than road stems, and can be much more tough and chunky to cope with the forces they’ll have to endure.
If your bike doesn't feel quite as you'd like it (perhaps it feels a little short so you feel cramped when riding, or a little too long so you feel stretched) then a change in stem is a very cost effective way to improve things. Or perhaps you feel too upright when riding you road bike – you could try a road bike stem with less of an upward angle (even switching to a negative drop, or a stem that flips between a positive and negative rise).
Stems range from standard simple aluminum units up to expensive, stiff and lightweight carbon exotica, and come in a range of shapes and styles. We'd always recommend finding the ideal shape for you and the riding you do.
Once you've decided on the width, shape is the next consideration. Modern race bars have a myriad of curves, drops and reaches. The 'classic' road bar has a drop (the curved section) that curves in a constant radius. The shape offers plenty of positions when riding low down in the drop as the constant curve doesn't place your hands in one position.
The next is the 'Ergo' shape, like on the 3T Ergonova bars , which changes the curve of the drop into a stepped, almost pistol-grip like shape to provide a set hand position wide riding in the drops. The size of drop itself varies between the 'classic' drop, usually around 150mm, and the latest 'Compact' designs.
A traditional or classic drop, like on the Zipp Service Course SL Traditional means you'll be lower when riding in it, and lower means more aerodynamic so in theory, faster. The downside of a classic deep drop is that if you struggle to stay in the drops for long periods of time, that aero advantage will be lost. The newer compact design reduces the drop to around 125mm (it changes between brands and designs) by effectively lowering the amount of drop, therefore bringing it closer to you. That makes it much more comfortable for most people, and means you'll spend more time down in the drops and although it gives less of an aero advantage, you can ride lower for longer, meaning a net-gain
Mountain Bike Handlebars
The first step is to decide which will suit the style of riding that you do. Downhill handlebars need to be extra strong to put up with harsh landings and riding over rough ground at high speed. Cross-country bars have a greater emphasis on low weight, while all-mountain and enduro handlebars need to provide a balance of both.
Bars can be made from any number of materials. Aluminium is the most common and also cost effective, but carbon-fibre is now popular as it is lighter, though more expensive. Carbon bars also help mute vibration and tend to be much stronger for the same weight. They will break rather than bend in a crash, so require careful inspection after any accident - in common with any component.
You also need to have the correct diameter of bar to suit your stem. The most common diameter is 31.8mm, but older bars can be 25.4mm and there's even an oversize 35mm standard being introduced by Easton that promises even greater strength and stiffness.
Mountain bike handlebars come in a wide variety of widths. It's down to personal preference but longer travel bikes tend to need wider handlebars that allow you to exert more leverage, helping force the bike to corner or to keep it heading straight on rough ground. Downhill bars can be up to a huge 800mm wide, but are commonly around 780-760mm. The downsides to wide bars are that smaller riders can feel very stretched. You're also more likely to clip trees and other obstacles. Most bars have guides that allow you cut them down to suit you.
For trail riding, a width around 740mm is popular. There are numerous options, such as the Race Face Chester bars or the lightweight Thomson Carbon All Mountain bars. Cross-country riders tend to use slightly narrower bars, from 680mm up to around 720mm. The lower width allows them to be lighter, as they don't need to cope with such large bending forces.
The extensions are the most important component of a triathlon or time trial handlebar set-up. They comprise of two long tube sections that extend far out in front of the handlebars, positioned either side of the stem. When riding on these extensions, your position on the bike is lower and narrower when viewed from the front. This gives you a massive aerodynamic advantage, perfect for when racing against the clock.
A full triathlon handlebar bar set-up requires dedicated brake levers and gear shifters so you can safely operate both gears and brakes when in the aero position. The best time trial handlebar setups can feature fully integrated bars which include brake levers as part of the package. For combinations of base bars and extensions or simple clip-on bar setups, you will have to move from the extension position to operate the controls. Remember to factor in the additional cost of the controls when buying a system.