Picking the right gears has a dramatic effect on how your bike rides and how much (or little) you wish to suffer when the road heads upwards. Our gearing-explained guide decodes any biking gear terms to make you more gear-savvy when it comes to your bike’s spinny bits.
When it comes to deciding what gear ratios your new bike should have, with all the choices available, it’s easy to get confused. Experienced cyclists, let alone anyone looking to take up cycling for the first time, become bamboozled by gearing options.
So we've put together this ‘Bike Gears Explained – A Complete Guide’ to help you decide the right fit for you.
What Does ‘Gearing’ Mean?
Bike gearing refers to the system that allows the rider to adjust the bike's mechanical advantage to suit different riding conditions. It consists of a chainset (or chainring) positioned at the front of the bike and a cassette (also known as sprockets or cogs) at the back of the bike, which work together to change the gear ratio. More specifically, it’s about the number of teeth each component has: the more teeth (t) a chainring has, the harder it is to pedal.
The opposite is true for the rear cassette; the more teeth there are, the easier it is to pedal. Derailleur gears are mechanisms that move the chain between different chainrings and cogs to change gears. The Front Derailleur shifts the chain between the front chainrings, and the Rear Derailleur shifts the chain between the rear cogs.
To make ascents easier, you would need smaller chainrings at the front and larger sprockets at the rear.
Chainrings
A chainset typically consists of 1, 2, or (in rare instances) 3 chainrings.
The smaller the chainset, the easier it is to spin the pedals.
Most bikes come standard with chainsets with one or two chainrings. A double chainset has an inner and outer chainring. The inner is the climbing ring because of its small number of teeth. The larger diameter outer chainring is better suited to flatter terrain and descending.
Chainring Ratios
Single Chainrings
- Also referred to as ‘1x’ in the cycle industry.
- It has no front derailleur for simplicity and greater chain security over rough terrain, where debris tends to clog the derailleur, forcing the chain to unship when shifting.
- Used in mountain biking for a number of years and is now gaining popularity in mainstream cycling.
- Ideal for Gravel Biking – Cycling in difficult terrain, off-road demands a lower gear range than you would typically find on any road bike. The 1x single chainring is an ideal fit for this, and nearly all gravel and all-road bikes come with it as standard.
- Depending on the model of the groupset, chainrings can be as small as 30t or as large as 44t.
Compact - 34/50
- The 34/50 ratio chainset has found great popularity among novice cyclists or seasoned roadies looking for more assistance on climbs
- Often the default option for the majority of endurance bikes on the market today
- Both inner and outer chainrings are quite small, making pedalling easier, handy when you hit the climbs
- The climbing assistance does come with a trade-off – The relatively small diameter outer ring will cause you to 'spin out' more quickly when descending
- Spinning out – When you run out of gears and your legs spin at speed but with little effect on your forward progress, i.e. going ‘full gas’ on the flats (if you're fast and fit enough).
- The 34/50 ratio chainset is also known as 'compact'
Semi-Compact - 36/52
- Known as ‘semi-compact’, this is an intermediate option for riders who still want some assistance on the hills but also desire more speed on the flats and descents. Rather than the 34/50 of compact, you now get 36/52 chainrings
Race - 39/53
- Not always strictly 39/53, but close enough!
- At the end of the 20th century, nearly every new bike would arrive with a ratio identical or similar to this.
- It was a standard 'race' setup and dates back to a time when your only options when buying a bike were simply double or triple-gearing.
- Today's racers will still use something very similar, albeit with a slightly larger outer ring.
- This ratio is fast on the flat but offers little assistance on the climbs. Therefore, only the supremely fit or dedicated racers still use it.
Cassettes
A cassette is a collection of cogs that sits on the rear hub and provides a select gear range for every riding discipline. In direct contrast to the chainrings, the larger the sprocket is, the easier it is to pedal. Large sprockets are more advantageous when climbing.
For a wide-range cassette, note the increase in cog size. The closer to the top, the easier it is to pedal.
The groupset a bike is supplied with will determine whether the cassette has between 8 and 13 sprockets. Entry-level groupsets typically have between 8 and 10 sprockets, whereas mid—to top-tier variants feature 11 to 13.
Select an appropriate cassette ratio for the terrain you expect to ride most often. For most assistance on the ascents when riding on the road, an 11-32 to 11-36 may prove most beneficial. Closer ratio cassettes such as 11/25, 11/28 or 11/30 are better suited to riders with a high level of fitness or those who typically stick to flatter terrain. Single-ring systems will feature cassettes with a much wider spread - anything between 11-42 and 10-50 are the norm.
Gear Ratios
Best Bike Gear Ratios for Climbing
Climbers ratio, otherwise known as having a 34/50 with 11/32 or 11/34 Cassette. Recommended for beginners or existing road riders who want the maximum amount of assistance for the climbs. With both a small and large chainring at the front, there's no need for a massive cassette at the rear.
The advantage of this combination is that when you change gear, the jumps between each individual gear are less dramatic. The smaller the steps between gears are, the smoother the action is when shifting from one sprocket to the next. A smoother shift results in less interruption of your pedalling rhythm (cadence). This is more pronounced with 1x systems owing to their much bigger sprocket sizes.
Semi-Compact 36/52 with 11/25 to 11/34
Amateur racers and riders with a decent fitness level may benefit from this setup. It still offers some assistance on the climbs thanks to its 36t inner chainring. However, the 52-tooth outer chainring offers the most benefits:
- The gap between gears is kept relatively small, which is ideal to avoid losing the pedalling rhythm when changing gears. Any loss of rhythm will also affect power output, making it less efficient. Therefore, opting for a smaller-spaced cassette like an 11/25 or 11/28 avoids any large jumps when changing gear.
- The gears do not 'spin out' as fast when descending. Spinning out is when you descend at such a velocity that when you attempt to pedal, your legs just spin furiously to zero effect. Sure, you can spin the pedals, but with no traction on the chain, it's just wasted effort. A larger outer chainring at the front means you can pedal for longer before losing chain traction.
- Specifying larger chainrings and/or closer cassette ratios makes the bike faster on the flat.
Pick Your Perfect Gear Combination
The gearing loadout of a bike will depend entirely upon the type you opt for and the groupset it comes fitted with as standard.
A hybrid bike will often have a chainring as small as 32t at the front and a road ratio cassette between 11-32 and 11-36 at the rear.
Allroad or gravel bikes will tend to be fitted with a larger chainring of approximately 40 to 44t in conjunction with a mountain bike ratio cassette between 11-42 and 10-50t. In reality, the gear range will be markedly similar, and you are less likely to be offered a choice of gearing.
We hope this guide helps you understand what to choose when buying a new bike. If you need more assistance, please do not hesitate to contact us.
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