The Bike List

Road Triple Chainsets – The Complete Guide

What is a triple chainset?

A road triple chainset (the crank arms and chainrings combined) consists of three chainrings. The big (outer) ring typically has 50 teeth, the middle ring usually has 39 teeth and the small (inner) ring most commonly has 30 teeth, known as a 50/39/30 combination. 52/39/30 is another less common road triple chainring combination.

Despite offering the most gears of any road chainset, road triple chainsets have become less common as compact chainsets have grown in popularity. Compact chainsets offer a middle ground between the more race-oriented standard road double and semi-compact chainsets with two larger chainrings (typically with 53/39 or 52/36 teeth chainrings) and heavier road triple chainsets.

More gears are better for less able riders, especially on consistently hilly terrain. A compact chainset however offers a similar selection of gears for a lower overall weight. With two chainrings there is also the advantage that the chainline (how straight the chain runs from the chainrings at the front to the cogs at the rear) will be straighter more of the time, which is mechanically more efficient.

What bikes do road triple chainsets typically feature on?

As compact chainsets have become more popular, manufacturers have started to replace road triple chainsets on a large number of sportive and recreational road bikes. However, there are still plenty of road bikes that feature road triple chainsets, or more often, bikes that are available with a road triple option.

Road triple chainsets feature most frequently on road oriented commuter bikes (flat bar road, town and hybrid bikes), entry level cyclocross bikes, touring and trekking bikes and as already mentioned, a number of recreational and sportive road bikes.

Click here to see all bikes that feature road triple chainsets.

What are road triple chainsets ideal for?

Road triple chainsets are especially well suited to touring bikes where riders might be carrying panniers or large loads. In this situation having a wider selection of gears is particularly useful, especially when tackling hills which would otherwise, be too steep to cycle up. Recreational road cyclists may also find road triple chainsets beneficial in hilly areas as they allow riders to pedal at a higher RPM up inclines (revolutions per minute) which is easier and more efficient, although usually slower, and makes seated pedalling easier.

Triple chainsets also feature heavily on mountain bikes (where cycling up steeper gradients is more common) however these usually use different chainring combinations which are better suited to the larger cassettes (the group of smaller cogs on your rear wheel) that feature on mountain bikes.

Top speed.

One downside to road triple chainsets can be that on the downhills or on fast stretches of road you may run out of big gears and be unable to go any faster than gravity will allow or you will need to spin your cranks at a very high cadence to generate power.

For example, using a 50 tooth (big) chainring and a 11 tooth rear cog (a common smallest cog size on the cassette) you'll be travelling at 32.04mph at a cadence of 90 RPM (revolutions per minute). Most people will naturally pedal at a cadence of between 80 and 90 most of the time, unless it's a particularly hilly ride in which case this number might be lower.

From our experience with a typical road triple chainring ratio of 50/39/30 and a smallest rear cog with 11 teeth you'll need to be going over 35 mph before you run out of big gears. In most places you'll need a good hill to get up to those sorts of speeds and even then you'll probably need to be pedalling fairly hard. If you are worried about running out of big gears then using a 52 tooth big (outer) chainring should help avoid this.

Bike List Top Tip: it pays to look after your components

Keeping your chainset, cassette (the group of smaller cogs on your rear wheel) and chain clean and well-lubricated can make a big difference to how efficient your bike is. If your chain is dirty it can be up to 7 or 8% less efficient - the equivalent of being 5 or 6 kgs heavier on a climb. Source - The Obree Way, A training manual for cyclists, Graeme Obree.

Converting a road triple chainset to a compact, semi-compact or standard road double.

Shimano 22 Speed Dura -Ace FC-9000

Changing from a road triple to either a compact, semi-compact or standard road double will typically require a new left shifter, front derailleur, chain as well as chainset which means this type of change is usually not cost effective.

Whilst we are comparing road triple chainsets to chainsets with two chainrings (these include compact, semi-compact or standard road double chainsets) it's worth pointing out that it's much easier to change from a compact or semi-compact to a standard road double or vice versa as this merely requires a change of cranks and in some cases (such as with Shimano's 22 speed Dura-Ace FC-9000 chainset, pictured on the right, where the Bolt Circle Diameter is the same on all cranks) simply just new chainrings. A longer (new) chain will also be needed when swapping from a compact to a standard road double chainset or vice versa.

The Bike List Top tip: replace instead of converting

Price up a conversion from two to three or three to two chainrings, and include labour costs as well as the parts mentioned above, as in some cases it can be cheaper to replace the bike with one that has the setup you want and sell the one you have.

What is BCD and why is it important?

BCD stands for Bolt Circle Diameter and is the diameter of the circle created by, in this case, the five holes at the end of the arms on the spider - the multi armed piece that connects the chainrings to the crankset.

The BCD number must be the same for both the crankset and the chainrings otherwise they won't be compatible.

The BCD on road triple chainsets is typically a combination of 130mm for the two larger (outer and middle) chainrings and 74mm for the small (inner) chainring. For comparison, the BCD on the majority of semi-compact and compact chainsets is 110mm and 130mm on the majority of standard road double chainsets.

These measurments are significant as each BCD places restrictions on the maximum or minimum size of the small chainring. The small chainring must have 38 teeth or less on a 110mm BCD chainset and must have 38 teeth or more (usually 39) on a 130mm BCD chainset.

What cassettes are road triple chainsets typically paired with?

Road triple chainsets are typically paired with cassettes (rear cogs or sprockets) that have an 11 or 12 tooth small sprocket as the smallest cog giving you a 50 + 11 or 50 +12 biggest gear.

They will also typically come with a cassette that has one of the following sprocket ranges: 11-23, 11-25, 11-26, 11-28, 11-30, 11-32, 12-23, 12-25, 12-28, 12-30, 12-32.

To work out gear ratios, speed at cadence or cadence at speed visit BikeCalc.com for more information.

Changing A Cassette

Changing a cassette is a cost effective way of adapting your bike to make it more suitable for different terrain. For flatter terrain where smaller incremental gear changes are an advantage choose a cassette with a close range such as 11-23, 11-25 or 12-25. A simple change to a cassette with a wider range of sprockets such as 11-26, 11-28, 11-32, 12-28, or 12-30 etc will make the same bike noticeably easier to pedal on hillier terrain.

If you shop around you can usually find a good cassette such as Shimano 105 (which strikes a good balance of value and quality) for around £25-£35. A like for like cassette replacement will usually be around 3-4 times cheaper than a like for like replacement chainset.

Read our guide to changing a  Shimano 10 speed cassette here.

The Bike List Top tip:

Most rear derailleurs will be capable of running a number of different cassette ranges. If the largest sprocket on the cassette is changing significantly in size make sure your rear derailleur can accommodate the larger sprocket. Most road bike rear derailleurs are available in a short cage (small gear range), mid cage (middle gear range) and sometimes long cage (wide gear range) designs.

Summary of road triple chainset:

  • 50/39/30 and 52/39/30 are the most common chainring teeth combinations.
  • Offers more gears than any other chainset. Typically 15, 18, 21, 24, 27, 30, 33 gears.
  • Very well suited to cycle touring and also ideal for the recreational road cyclist, those new to road cycling and those riding in hilly areas.
  • Heavier than double chainring chainsets so not ideal for the weight conscious.
  • Using the smallest (inner) chainring allows for seated climbing up all but the most severe inclines.
  • More efficient when pedalling up hills compared to a standard road double or semi-compact chainset thanks to the easier gears on offer.
  • The smallest cog on the cassette will typically have 11 or 12 teeth.
  • Can run out of big gears on fast roads or descents but typically only over 30-35mph.
  • Shares the same 50 tooth large outer chainring as a compact chainset and therefore shares some of the same gears.
  • The chainline won't be as straight as often when compared to chainsets with two chainrings making a triple slightly less efficient.
  • Chainging from a road triple chainset to one with two chainrings is often not cost effective as it requires a new chainset, left shifter, front derailleur and chain.
  • The two largest chainrings on a road triple chainsets typically have a 130mm BCD. The smallest inner ring usually has a 74mm BCD.

To find out more about compact, semi-compact and standard road double chainsets click below to read our comprehensive guides.

Compact Chainsets - The Complete Guide

Semi-compact Chainsets - The Complete Guide

Standard Road Double Chainsets - The Complete Guide