Marto32

So I'm fairly new to road biking, ~2 months, and I ride 20 - 30 miles on Saturdays and Sundays. I've noticed that I primarily use my big rings and switch between my back rings to 'fine tune' the resistance.

For example, If I'm climbing I'll shift to the smaller of the big rings and if it's still tough I'll use the back rings to make it easier. As I reach the top I'll shift the back rings to a middle gear and then switch to the big ring in the front on the descent and fine tune as needed.

So I would say I switch between the front big/small rings 80% of the time and use the back rings the other 20%. Someone at the LBS said that I should use the front rings 10% of the time and the back ones 90%. My question is; which way is correct?

Today I primarily tried to use the back rings but in order for me to maintain an 80rpm cadence I end up nearly cross-chaining...

Jed19

Yep, the back cogs are meant for fine tuning. That is where most of your shifting should be at.

nathan.johnson

How you shift is up to you, but there is less of a jump between changes when you use the back versus the front. And there is a lot of overlap between gear combinations. For instance my front chain rings have 52 and 34 teeth and my back cassette has 12-13-14-15-16-17-19-21-24-27 teeth. Using https://www.sheldonbrown.com/gears/ I can find that being in the 34/12 is about the same as being in the 50/17. And being in the 50/21 is about the same as the 34/14. And the 50/27 is about the same as the 34/19.

So the best thing for me, and I think a lot of other people, is to pick the front chainring based on the terrain and then change the rear gears to maintain your preferred cadence. Then if you get a point where the terrain changes drastically, like going from flat to a 10 mile long 7 percent grade, then switch to a different chainring in front. If you're puttering along on a flat in the big chain ring and come to a small hill, you probably don't want to switch to the small ring. Instead, change to a higher-toothed gear (easier) in the rear and just pedal harder until you make it over the top. Then you'll still be in the big ring for the descent.

Marto32

Going by this I would choose the larger chainring except I think it would still be difficult to keep an 80 rpm cadence without cross-chaining.

travelerman

You're going to find that, the more you ride, the higher your cadence rpm; I try to pedal out a consistent cadence (usually in the 90's), while maintaining roughly the same resistance. This is when I shift; when changes in resistance (usually due to elevation changes) begins to affect my cadence. Obviously, very steep elevations are going to slow your cadence on the climb, while speeding it up on the descent. There are times when I shift to a higher gear just to gain more speed, and once I retain my preferred cadence - barring any severe elevation changes - the resistance evens when as my speed increases.

Mithrandir

It's up to you, but most people typically use the rear shifter a lot more often, because the jumps are smaller and less jarring. I personally like to keep my cadence as steady as possible, so I typically only shift up or down on the front when I reach a limit on the back.


So I go from 2-7 to 2-8 to 3-3 to 3-4 when shifting up, and 2-3 to 2-2 to 1-7 to 1-6 when shifting down (triple chainring). I customized my gearing so that the three ranges of gears don't overlap too much, so I just avoid 1-8, 1-9, 2-1, 2-9, 3-1, and 3-2 to avoid cross-chaining, and the rest of my gears provide a continual range. The jumps between my front chainrings are rather large and it's unpleasant to switch between them all the time.

mkadam68

+1

In any event, try to aim for a fast cadence (how fast your feet go around). The starting point is considered 90rpm's. Some people higher, some people lower. Adjust your gearing so that you can maintain this 90rpm's.