Make sure you have the right gearing for the TDK

This years TDK involves some SERIOUS climbs.  Do you have the right gearing?

By Stuart McDougall


God did not invent gears. Men invented gears – because we are not gods.

 This years TDK includes some serious climbs – a total of over 11,000 metres over the week – including a massive 3,800 on day 2 featuring gradients in excess of 10%! Your legs will feel those climbs.


This post is intended to help you make sure you have the necessary gearing to enjoy the climbs on the TDK (hint: you may need to make some changes).


In simple terms, the drive chain on your bike has chain rings at the front which are attached to the crankset. Mounted on the rear wheel is a cassette of sprockets. In relation to the cassette, the sprocket teeth combinations vary depending on the type of riding you plan to do.  Most Sydney riders would use a cassette with a range of 11-23 or 12-25.


If you have a standard crankset then you will have a big ring which has 53 teeth and a small ring which has 39 teeth. 


This relatively standard “Sydney Gearing” is not going to cut it on the “bergs” you will encounter on TdK! These are NOT climbs where you can stand and power it up for a few hundred metres. Each climb will take 1-2 hours depending on your fitness & climbing ability. If you want to enjoy the climbs then we suggest you have your bike set up with a better climbing gearing. This would include fitting a cassette with at minimum 12-27, if not 12-29 or 12-30, and in combination with a compact crank (a crankset which permits the use of smaller chain rings). A compact crankset usually has big ring of 50 teeth and a small ring with 34 teeth (there are also some variations such as 52/34, which give you the advantage of the 34 inner ring for climbing, with a 52 big ring so you will have still have top end speed).


Both Campagnolo and Shimano offer compact cranksets with 50/34 gearing, as well as plenty of wide range cassettes. The latest model Campagnolo, Shimano and Specialized cranksets have a crank design that allows the installation of both 53/39 and 50/34 ring combinations onto the same crankset. You will ordinarily need to also fit a new chain as it will need to be shorter than the chain you run on the standard crankset. As you may only have the compact crankset on the bike for the duration of the trip, the old chain (if in good condition) can be reinstalled with your standard crankset. The shorter chain can be kept with the compact crankset for use on some future mountain adventure.


Talk to your local bike mechanic early to ensure the parts can be sourced and fitted in time, or if you are into DIY, have time to get the bits from your favourite Internet supplier.


Remember:  This years TDK involves some SERIOUS climbs.  Make sure you have the right gearing.


- Stuart McDougall