worldtraveller

for when i ride my road bike which is a lot.

I used to ride lots in big ring, now i learned t that it is better to just spin
so i ride in smaller ring and just spin lots and use gears from there.

When should i use by big chain ring.

I like doing 45 km to 100 km rides on a regular basis
recreational rider at serious level

with intention to maybe get back into racing some day again

DataJunkie

Find a nice cadence that you like and adjust accordingly.
I like 80. Others like 100 or more or less.
Don't restrict yourself arbitrarily to any particular ring.

JWSpeed

Totally agree with Data! It is all about efficiency, and that depends on the person. The pros spin 100+ and are in the big ring. I would assume you just do not want to be lugging in the saddle up a 6% in a 53x15 @ 45 RPM.

gregf83 

If you're planning to race, ultimately you want to ride at whatever cadence gives you the most power. As DataJunkie mentioned, cadence is individual, and if you've been riding a lot, you should have found a comfortable cadence by now. Usually, cadence goes up with intensity, but it is not a causal relationship, i.e. riding with a higher cadence will not give you more power.

PatW

As Data mentioned, cadence is individual. Lemond liked pushing big gears at a low RPM of about 80. It got to be the style for many people to imitate Lemond. I understand that Armstrong rode a high cadence so the style switched. Far be it for me to say that either Lemond or Armstrong could have been a better rider if they had ridden at the proper cadence.

Now, I know some people who say that you should ride on the big ring and big cogs for better wear patterns. But heck, how much are you really saving? So chose the gears that let you use the cadence you prefer.

Drew Eckhardt 

When you can get a good cadence with it and can get one or more of
- Closer spacing between gears (IOW, with 12-13-14-15-16-17-18-19-21-23 in back the next gear would be closer if you were riding 53x18 instead of 39x13)

- A less noisy chain line (in the same situation 53x18 near the middle of the cassette is going to be quieter than 39x13 one cog in from the end)

- Less front shifting (in the same situation the small ring wouldn't leave you any room to speed up without being fully cross-chained and you'd want to stay in the big ring. OTOH, if you were headed for a hill where you'd need something smaller than 53x21 you might spend a short time in 39x13 before you got there and started shifting to bigger cog).

"Good cadence" may or may not be what feels best and is intensity dependent. Although I used to prefer pedaling around 80-90 RPM I found that I could ride threshold intervals on consecutive days at the same power staying over 90 RPM. 5 minute intervals work better at 100-110 RPM. At 30 seconds I'll get more speed if I'm not shifting until 110-120 RPM.

Carbonfiberboy 

On my single, I prefer to shift just the rear when I can. It's easier. I have a 30-42-52 in front. I can stay in the middle ring almost all the time if I want. I ride pacelines a lot, so I see a lot of cassettes. Most folks seldom ride in the big ring past the middle of the cassette. Folks with a triple seldom ride past the middle of the cassette in their granny ring. Most folks will run the whole cassette in the middle ring. When I'm on a bike with 39T middle or small ring, I run out of gears pretty quickly when the road tilts down a hair, so I'll run in the big ring more than when I'm on a bike with a 42T ring.

It helps a lot if you can spin, so then your gear choices are broader.