gears

Gears for touring

Gears For Touring

As I've said before, if you want to go cycletouring you can use any bike, but once you're hooked you
need to get a steed that will take you high and far... One of the most, if not the most important
considerations for touring is gearing.

Traditionally gearing is measured in inches, but I'm not going down that trail a) because it means
nothing to the beginner, and b) it'd take longer to explain than the gearing itself, so here's an idiot's
guide...

Let's start with an example... I'm a plodding cycletourist, I can cycle 100 miles in a day but it'd kill
me, but I normally average 40 on a tour. I'm fit enough to run upstairs, but not to run a mile. In
effect I'm a pretty typical 38 year old! However last year I cycled up all the major cols in the
Pyrenees, carrying full camping kit, without any problems and without having done any cycling for
four months previous. For those of you thinking there's a major contradiction somewhere the secret
is in the gearing of my bike.

Basically if you are going to do loaded touring and don't like pushing, a good rule of thumb is that if
you can still keep riding then the bottom gear isn't too low. I for example can ride happily down to
gentle walking place, about 3-4 MPH, and so my bike is geared so that at this speed I'm still turning
my legs over at a reasonable one revolution per second. This is a much lower bottom gear than most
off the peg bikes, but it's always nice to have such a "Granny gear" in reserve even if you use it once
in a blue moon. On my bike, which is equipped with 700c wheels, I get this sort of bottom gear
using a 24 tooth inner chainring and a 32 tooth rear sprocket. A few years ago such a set up would
be difficult to achieve but now those nice mountainbike people have provided us with "microdrive"
chainsets, typically 42/32/24 which make super low bottom gears pretty easy to obtain. As a rule of
thumb your biggest rear sprocket should be bigger than the inner chainwheel. If you ride
mountainbike sized 26 inch wheels these automatically drop your gearing by a couple of teeth over a
700c wheel by virtue of their smaller circumference.

The use of a microdrive set also means that a lot of your gears will be pretty low and for loaded
touring this is how it should be. When working hard on a climb small gear differences can make a
big difference to how tired you get, a choice of several low ratios means you can keep your climbing
rhythm going as the hill varies in steepness. On the other hand bowling along the flat you're
generally working less hard so need a lesser choice of ratios, if your top gear isn't big enough to
pedal downhill then big deal - just stop pedalling and coast, it's not an option up hill!

So to put my money where my mouth is, for 700c wheels a 24 or 26 inner chainwheel and 30 or 32
rear sprocket is ideal. With 26 inch wheels a rear sprocket of 28 will probably be as low as you can
ride without wobbling into a ditch...

Of the available sets I have one favorite and that's Shimano's STX especially the triple chainset. It's
well made and offers ideal ratios of 42/32/24. It also uses steel chainrings which in my experience
last about 3 times as long as aluminium - using such small chainrings does make this important. The
matching derailleurs are of good quality and I like the 7-speed hubs which build a stronger wheel
than more exotic 8 speed hubs. As for the freehub casette, Shimano do a lovely 14-32 seven speed
set which is hard to get but perfect. The new cassettes with a 34 tooth biggest sprocket are not as
good as there's too much gap between bottom gear and the next - remember you need closely spaced
ratios for climbing. With this set up you should have set of ratios that will happily handle speeds
between 3 and 20 mph, even if you're a plodder like me...