Cycling - Gear/Equipment

Cycling Gear: Choice between a Double, Compact or a Triple Crankset

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Choosing your type of crankset or the kind of chainrings is an important decision when buying a bike. A bike sporting a triple crankset, usually was shorthand for ‘I can’t climb’. A modernization of gears and a slight change in the mindset was enough to introduce road bikes to triple cranksets. Compact chainsets are known to have become rapidly popular leading to many makers and manufacturers replacing road triple chainsets on many of the recreational and sporting bike styles. Road triple chainsets can be easily noticed being featured on entry-level cyclocross cycles, trekking and touring bikes, road oriented bikes for commuting along the lines of hybrid and town bikes, flat bar road, and not to forget the sportive and recreational types.

Another popular source of the controversy lies in the choice between a compact, a double and a triple chainring. Each type, of course, has its advantages and levels of personal fitness, riding conditions and geography have a role to play in this choice. 

A bit of background information a triple crankset typically means having three chainrings up in the front, similar to those found commonly on most types of mountain bikes. They are also known as ‘Triples’ and were fairly uncommon for road bikes because of a. ready availability and b. the purported theory that a cyclist with triples cannot climb, or need additional help with it. More as a response to a crowd of mountain bikers adapting to road bikes than as an elimination of the theory, about a decade has gone by with manufacturers adding triples to the specifics of road bikes.

Change in the Trend

Due to the switch to smaller gears in the mid-2000’s, compact double chainrings came into the picture, which is commonly used on most of the contemporary road bikes. With the onset of the compact double, many believed that the triple cranksets had moved over to the passenger pigeon side which wasn’t exactly the way.

Over time, the realization had struck cyclists - owing credits to the mountain bike - that bikes obviously climbed much easier and better when they have three gears up front. Therefore, the triple chainring though undermined by the favored compact double is still operational and is quite mainstream when it comes to road bikes like the Shimano Triple Crankset Road or the Bicycle Crankset 400.

shimano triple crankset road
Shimano Triple Crankset(Source)

Making the Switch

There are two ways of making the changeover to your cranks: either you purchase cranks with a specific design for three chainrings, or you convert your double-chainring cranks.

Few things to keep in mind for the conversion - you’ll need a ‘Tripleizer’ chainring, which is particularly created with a built-in spider (mostly for 74mm BCD chainrings). You’ll also need to change your bottom bracket spindle by around 5mm to 9mm. In order to get a professional opinion or help, when ordering your tripleizer specify the kind of bike you’re going to be putting it on, ( bikes with thick tubes need more of clearance, therefore a longer spindle compared to normal sized tubes) the cranks that you’ll be attaching it to and the small chainring that you plan to use. In case your bike sports a cup-and-cone bottom bracket, the spindle will need to be exchanged.

shimano triple crankset 10 speed
74mm BCD Chainrings(Source)

In case you have a cartridge bottom bracket, a new spindle can be installed, but there’s a high likelihood that the whole thing will need to be swapped. There shouldn’t be any complications with running a Triple Crankset 9 Speed on say a Shimano Triple Crankset 8 Speed drivetrain since some 9-speed cranks have been listed as 8/9 speed cranks, but the front derailleur might need a bit of adjustment to make space for the bigger ring.

Also, a simple fix is to upgrade to a compact crankset which still counts as a double but has smaller chainrings in the front instead of bigger gears at the back. While most of the double chainring cranksets tend to have a 39 tooth low gear a compact crankset will give you a 34 tooth low gear which makes a whole lot of difference.

Understanding Tooth Count

Speaking of different tooth count let’s know what each setup has:

  • A double crankset typically boasts of a 39 tooth small ring and a 53 tooth big ring.
  • A compact double incorporates a 36 or a 34 tooth small ring and a 50 tooth big ring.
  • A standard triple will have a 52-42-32 gear combination but has of late shifted to a 59-39-30 which is typical of a standard crank with a ‘granny gear’.

However, no tooth count can be categorized as ‘standard’ anymore, since most manufacturers use a variety of gear combinations, with some even offering over 100 varied combinations of crankset-cassette gearing.

The Trick with Gear Ratios

So what if you have a road bike fitted with a double chainring setup and are going through a downhill struggle to locate a gear low enough to take you uphill without popping your knee? Simplest and even cheapest solution are to opt for bigger gears at the back, which means switching your current cassette.

While it’s easy enough to switch back from the new to the old, bigger gears are a clear indicator of larger gaps in between gears which leads to gauging and settling into a decent and comfortable pedaling cadence is a task, especially in case of flatter terrains.

Many techies could spill out gear ratios in split seconds but mathematics plays a big role in calculating how gear ratios will tell on your performance levels like for instance touring triple cranksets 48-36-24 have a range of 18-113″. Simply put, bigger rings having bigger teeth means pushing higher gears which are harder, and smaller rings with lesser teeth mean pushing lower gears which is easier.

Double Crankset

The double crankset is the oldest crankset model for road bikes typically of cyclosportive riders and hefty messenger bikes. It incorporates five arms, now with the more four arms trending as well. More often than not it sports 53/39 chainrings but options of other combinations like 52/39, 52/42, or 50/38 are also available.

shimano triple crankset 11 speed
53/39 Chainring(Source)

Read: How to handle Two Piece Crankset!

Triple Crankset

A popular choice among cyclo-tourists, or even anyone who doesn’t like riding uphill, is slowly dying out with Shimano and Campagnolo still selling few specific types. The three chainrings make for a wide gear ratio enabling tackling hills of any size. Most common combinations available are 48/38/30, 42/32/52, 52/42/30 and 50/40/30. With its 74 mm spacing, a small tooth chainring can be easily mounted with a cassette going up till 28 teeth.

shimano triple crankset road
52/42/30 Triple Chainring (Source)

The Q factor which is the distance between the two crank arms is relatively bigger than that of a traditional crankset proving a slight problem to some. Also adjusting the triple drivetrain requires a bit more delicacy than a double chainring. Not to forget, a triple drivetrain can add up to and more of 300 gms to your bike.

Compact Crankset

Parading as the most popular model, and again borrowed from mountain bikes, like the double crankset, the compact crankset bears two chainrings and a spacing of around 110 mm, enabling mounting of smaller chainrings of up to 33 teeth. Its options of 10 and 11-speed cassettes incorporating sprockets from 30 to 32 teeth offer a wide range, however, also has a bigger gap in between each gear. A good option to explore is the compact crankset 450.

compact crankset 450
Compact Crankset(Source)

The compact crankset 450 is a great choice if you’re struggling to find a lower gear when climbing. 52/36 (also known as a semi-compact) and 50/34 are more of the common combinations to consider.

Read: Everything to Know About Compact Crankset!

The Double Compact

Of late, there doesn’t seem to be a choice between a double and a compact chainring since both these models with their 110 mm spacing make for mounting chainrings between 34 to 56 teeth without any loss in rigidity. What’s more is that all crankset models are aiming to fit both double and compact chainrings with equal ease.

The Single Chainring

As is suggestive from its name, the latest entry in the world of road cycling has only one chainring. Mainly aimed at gravel and city bikes, and Cyclocross, it’s less of maintenance with no front derailleur and makes the bike much lighter as well. The lack of the derailleur, however, means that it has to have a specifically designed chainring with special teeth which can make don for extreme cross chaining on the sprockets of the cassette.

Few Shimano Models

  • The Shimano Triple Crankset 11 Speed: This comes with a 40/30/22 with a 50mm chain line and a 168mm Q-factor which makes it ideal for all-mountain use paired with an 11-40T cassette.
  • Road bicycle crankset 400: The road bicycle crankset 400 or the bicycle crankset 400 comes with a crank arm length of 170mm and a bolt circle diameter of 130mm.
  • The Shimano Ultegra Triple Groupset 6703 is an optimal balance of stiffness and lightweight, a perfect choice for competitive and enthusiastic riders.
  • Shimano Crankset 1,100
  • The Shimano Triple Crankset 10 Speed sports an external bottom bracket system of a rigid yet lightweight pattern and SG-X chainring provides a smoother and faster gear shifts under load.
  • Ultegra crankset 450: The Ultegra crankset 450 incorporates a four-arm design. The BCD in place allows for front chainring combinations from 55-42T to 46-36T.
shimano ultegra triple groupset 6703
Ultegra crankset 450(Source)

Summing Up

Your intentions and level of personal fitness are what should ultimately lead you to choose between a compact, standard or a triple crankset. A triple crankset is ideal if you’re not as strong as previous, you often ride or live in a hilly area, are a commuter or a recreational cyclist. What ultimately matters is that you’re comfortable, and you’re enjoying your ride.

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