CASANOVA'S PRO SHOP

 

Bike Gearing Reviewed

By Gene Casanova

 

Should I Buy A Triple Or A Double Crankset?

Excellent question!

The Correct Start To Fitting Yourself To The Right Bike For The Application.

If The Bike Will Be Used For "Loaded Touring", Expedition Packing, A Triple Is Definitely A Must.

If The Bike Will Carry Extra Gear, Or Tow A Trailer, Be Ridden In Hilly Areas, The Rider Is Out Of Shape, Light Touring In Hilly Areas, A Triple Crankset Would Be Wise.

The Purpose Of A Triple Crankset Is To Add More Very Low Gears, Used To Make Uphill Peddling A Load Easier.  These low gears are referred to as granny gears; since the speed low gears produce is very slow.   A triple crankset drive train, tends to shift a little slower than a double gear crankset, with a closely spaced cassette.   Intelligent thinking provides for proper gearing; you will be glad of it at the end of a long day in the saddle.  The cost to upgrade to a triple crankset drivetrain will be lower than upgrading later.   Make the decision before purchasing a new bike.   Most quality bike can be upgraded with a triple crankset drivetrain.

What's Compact?

'Compact' refers to a smaller chainring-bolt-circle on the front chainweel.  This enables a smaller chainring combination.  A standard out-of-the-box bike's double crankset gear combination is 53/39, which replaced 52/42.  Compact means changing the crank and chainrings to 50/34, 50/36 or 48/34. This enables a whole new range of gearing with a double crank and they have become very popular, particularly with those who are desiring easier gearing.

It is important to maintain the efficiency of shifting, and therefore a "Compact" front derailleur is needed.  Campagnolo offer a wide range of carbon and aluminum cranksets and front derailleurs in the Compact configuration.  Shimano do not, but there are an increasing number of "Compact" cranksets and front derailleurs developers becoming available.

Bike Gears?

A Bike's Gears Are Formed By Combinations Of A Front Sprocket And A Rear Sprocket.  Regardless of the type of bike, it will not feel right peddling, unless the appropriate gears are used for the rider's fitness level, the type of peddling and the riding environment.

Chainrings and Cogs
There are sprockets on the front and back of a bike.  Front sprockets are called "chainrings". A sprocket connected to a peddle arm is called the 'crankset'.  A crankset can have 1, 2 or 3 sprockets.  When 2 sprockets and a peddle arm are connected this is called a "Double Crankset"; When 3 Sprockets Are Connected Together With A Peddle Arm, It Is Called A "Triple Crankset".

Triple cranksets include a small inner chainring that offers easier hill-climbing gears.

Sprockets On The Rear Wheel Of A Bike Are Called "Cogs".  A Group Of Two Or More Cogs Connected Together Is Referred To As A "Cassette" Or "Freewheel".  A Cassette Is Attached To The Rear Wheel To Transfer Peddling Power To The Wheel.   There can be 8 to 10 cogs in a cassette.

How Many Gears?

To determine the total number of gears a bike has, simply multiply the number of front chainrings by the number of rear cogs.

Example --- A bike with a triple crankset and a 10-cog cassette, has 30 gears!  This Would Be Referred To As "Extreme Gearing"!

How many gears does one need?  This question depends on the individual, and should be based on real needs.  If the rider is reasonably fit, and the bike will be ridden mostly in flat terrain over payment and concrete roads, a double chainring with 8 to 10 rear cogs should provide for a range of gears easy to peddle for the rider in the riding environments.  If the terrain is hilly, or steep, or the bike will carry loads, consider a triple chainring that provides the full range of high speed and low vertical hill climbing peddling with ease.

When considering how many rear cogs is right for a bike, keep in mind the multiples.  2 chainrings and 8 cogs equals 16 gears!

When adding gears to the total count of cogs in a cassette, consider this --- Adding more cogs adds a wider range of gears plus more-closely spaced gears.  The closely spaced gears are excellent for racing and training because it makes it easier to fine-tune pedaling effort.  Wider gearing offers easier low gears so it's ideal for mountainous riding, load carrying or when the rider is out of shape!

Peddling-Feel Of The Gears?

To determine how easy it will be to pedal a selected set of gears, chainring and cog information must be studied.  Chainrings And Cogs Are Identified By The Total Number Of Teeth Each Has.  When Reading Bike Builder's Specifications, One Might Read 39/53 Chainrings And 12-23 Cassette. This Translates To Two Chainrings, One With 39 Teeth And The Other With 53 Teeth; And, A Cassette With The Smallest Cog Having 12 Teeth And The Largest Having 23.  To Know The Other Cogs In The Cassette, One Would Have To Count Each Cog's Teeth!

In Simple Terms, Larger chainring numbers translates to peddling power being increased to the rear cogs; this also means more peddling Force Is Needed.  Larger Cogs Translate To Easier Peddling Force And Higher Output Speed.   By keeping these simple ideas in mind, one can get an idea of peddling forces expected from a gear set.

Example --- A 30/42/52 Triple Crankset With A 12-30 Cassette Will Offer Much Easier Peddling Than Compared To A 39/53 Double Crankset With A 12-23 Cassette.

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