This TA cyclotouriste 60T outer ring was used in trips around much of Australia in the 1970's

Over the years World Randonneurs have been upgraded from 15 speed, to 18, to 21, to 24 and to 27.  As a result of this, we have had to use thinner chains and thinner rear cogs. Not surprisingly, the thinner these components are the lower is their life expectancy.

In the bike racing world it makes sense to do whatever it takes in order to go faster. It is fine for those bikes to have a short life expectancy in running gear. But in the touring world, we have to make sure our bikes last as long as possible. Components can be replaced but this is not something tourers want to have to think about. The bikes and luggage are heavy enough and we don’t like to have to carry too many spare parts. Long wearing components are preferred.

9 or 10?

For the hard working bikes being suited to touring, the line is drawn at 9 speed. Reports from the bike racing world on the life expectancy of 10 speed chains and cassettes is such that we do not offer 10 speed cassettes on bikes designed for touring. This is especially the case for bigger, stronger riders and for tandems where the rear chain endures double the tension of a normal chain. Keep in mind we have loads on board the bike much of the time.

We have been monitoring just what distances we are getting out of chains, cassettes and chainwheels, assuming no chain rotation. These distances vary mainly with the chain model itself, chain cleanliness, the total mass of rider+luggage and the rider's normal acceleration power. The minimum distance to expect is 8,000 but most cases could exceed that.

Chain lubrication.

People refer to chain “stretch” but chains are not actually stretching. The metal is not elongating under tension. Chains do lengthen but this is the result of grit wearing the hinge pins and sleeves of the chain. This grit initially adheres to the outside of the chain but does little harm there. It is when the grit reaches the inside of the chain that wearing occurs. Oiling a dirty chain virtually guarantees that wear will increase.  It is the elongated chains that cut into the teeth on cogs and cause them to wear to the point that chains slip. Then all the cogs and the chain need replacement. So it is wise to wash a chain with solvents occasionally. Oil them lightly only when they are clean. If the chain looks wet you have put too much on. Just wipe it off.

Rotation.

Cyclists who use a bike almost exclusively and only use occasional public transport, plus go on a few tours, can expect to ride a lot of kilometres a year. For most of them it will be 5-10,000km a year. If the commute is over 10km each way, this increases.   

Some cyclists doing these distances extend the life of their chains and cassettes by having two chains and rotating them every 2-3,000km.  This significantly extends the life of the middle chainwheel and cassette cogs. On a tour under 3,000km though, the spare chain is avoidable extra weight. It is a strategy for use in your home city. Then, unless it is a tour lasting many months, people carry only a few spare links of chain. They still need to be prepared for a chain breakage. 

There are now excellent chain connector systems such as the Wipperman Connex. If you adopt the rotation idea you will find it a lot easier to manage with this "quickconnect" system.

Hub gear systems.

In the decades of development of World Randonneurs there has been no pattern of problems with chain gears and we have not developed an internal hub gear option. However Rohloff, which began testing in 1996 and now has an impressive record, is highly respected in the long distance fraternity and we are developing test bikes that use their hub. The system is costly but Rohloff claims it pays off due to the higher life expectancy of the system. It seems a pity that Rohloff gear levers are not developed for drop bars, so that is a hurdle. Also, although they use single cogs and could use 1/8”, they use 3/32”. They passed up on the advantage of super long-wearing 1/8” chains for the sake of the weight difference. When they were developed the makers were concerned about being tagged as "heavy".

Enclosed chains, which are possible on these systems, are an option. They must improve chain life. We are developing test units and will test them in Africa.

  

 
HomeAbout UsProductsWhere to buyTechnicalTravellingContact Us
Site by Magicdust Affordable Website Design

  

 9 speed chaingears.

Over the almost four decades, during which our bikes evolved, there have been remarkable developments in the world bike industry. In the 1970’s the earliest versions of our bikes had 5 speed, 14-34T, screw-on clusters. Cassettes were not yet invented. The bikes had triple "TA" chainwheels in larger sizes than are now used, due to the clusters only going down to 14T. Now, touring cassettes are 9 speed and the range is 11-32T.  So, outer cogs of the chainwheel sets are 48T, or a bit less.

Behind the increase in the number of cogs on cassettes, is the fact that small gear changes are more efficient than large ones, and that the more ratios a bike has the better chance a cyclist has to be in what is the ideal (preferred) gear ratio. It is quite ironic that, in the face of this, over recent years there has been a growth in the use of single speed bikes. Remember that those single speed bikes generally carry little or no luggage. But they are common even in very hilly San Francisco. It is true that small gear changes are more efficient than large ones but we can still manage with big jumps and, on bikes without luggage, even a single ratio is ok.

The efficiency benefit of having more “steps” in a gear system is especially relevant to racing bikes and bikes that are expected to carry a load, whether it be a city-dweller’s shopping or a cycle tourer’s luggage. Road bikes don't need the range so much. They just need gears close together. But laden bikes need a greater range, from lowest to highest. The benefit we have taken when we went from 7 to 8 then later from 8 to 9 was not wider gears but closer ones.