Choosing the right gear

Depending on your bike strength, the race you’re training for, and the terrain you have to train in, it may be worth looking at changing the size of the chain rings and cogs on your bike.  Most bikes will come fit with the standard 53 tooth big chain ring and a 39 tooth small chain ring.  On the rear of the bike you’ll typically see a  12/23 cogset.  If you live in a mountainous area, you’re probably best sticking with this standard set up.  Even so, there are some pretty good alternatives that you may want to try.

Some may find that the 53 tooth chain ring is just too big, or too hard to ride most of the time.  And rightly so.  How often do you find yourself in the 53 tooth front ring and the 12 tooth cog a the back?  I would wager not very often at all unless you have some long descents in your training grounds.   Even then, you’ve got to be going over 60km per hour to spin that gear out.  Then there’s always the situation where you hit a hill that’s not quite long enough to bother switching to your 39 tooth chain ring so you just grunt it over the top in your big ring.  Or the dreaded, ‘oh crap I’m not going to make it in my 53, I need to switch half way up but can’t because I have to keep pedaling and I’m not going fast enough.’

Anyway, enough about the problems of a 53/39, here are some alternatives that you may want to think about.

Switch the 53 for a 52 tooth chain ring.  The 52 tooth chain ring is a great alternative.  It’s enough to notice a difference but not so much of a change to lose the gear you’ll need when going 50km/hr.  To ease your mind on this change – At the Junior cycling level they impose a gear restriction of 52 x 14.  And these guys and gals are still doing Time Trials with average speeds at just under 50km/hr.  It won’t slow you down any(only on the descents), put it that way.

Compact Cranks: These typically come with a 50 tooth big ring and a 32 tooth small ring.  You may want to try this out if you really have a lot of difficulty climbing in your easiest gear, or have never touched the lower cogs when you’re in your big ring.  The 50 tooth front ring will create a better chain line (less friction supposedly) and allow you some more freedom in rolling terrain.  The 32 small ring is small, but you can get a 36 very easily if you’d like to bring it up a bit.

Another option that we enjoy using is the 42 tooth small chain ring.  You won’t want to do this if you have even the slightest amount of difficulty with a 39, or live in a mountainous area with those long 10 km+ climbs.  A 42 tooth small chain ring is heaven for most half and full Ironman races (North American ones anyway) and athletes with a good pair of cycling legs.  You’ll find with a 42 that you’re less reluctant to switch into the small ring when you want.  You can even cruise nicely at ~35km/hr holding a respectable cadence.  It is truely our favorite switch for most terrain.  And if you happen to hit a long 20km climb…well, enjoy the burn.

And to quickly sum up some other options.  A 54 tooth big ring – great if you know you’ll be on a flat fast race course and have some strong bike legs.  Using an 11 x 21 tooth cogest on the back can  give you a couple more options on the fast courses as well.  Or use a 12 x 25 tooth cogset to give you an extra gear for the big climbs.  The drawback with a 12 x 25 is that this puts a lot of space between some of the gears.  It can be hard to find the sweet spot with this gearing, but good if you have a wide variety of terrain to train on.