When climbing up the hill or accelerating, do you usually shift while applying full pressure to the pedals or do

lower the pressure first and then shift?

The reason I got interested is because I heard a biker shift this morning about half a mile down the hill.

Let's see what way gets the majority.

I ussally shift under pressure, I am wondering if I should not do that, because when I do that my chain will jump the teeth. I think I might have striped the teeth on the back #6 gear because now when I apply alot of pressure on it, it will still jump even when I do not shift.

I have mechanical sympathy. I hear my drive train screaming in agony if I shift while pushing on the pedals.

There's an art to it. You give a little extra push on the pedal stroke before the shift, ease up on the shifting pedal stroke then a hard push on the next to make up for the lost pedal stroke. Of course, this requires that you get the shift done in one pedal stroke or it's crunchy-crunchy time.

What F1 Fan said. You shouldn't shift under full pressure. Your manual should even tell you that, but it's hard on the drive train...sorta like trying to shift a manual transmission without using the clutch.

Shifting under pressure is horrible, puts tremendous stress on the gears and chain, will wear them down alot quicker.

Would you shift your car like that?

I try to ease up on the pressure and am able to do it most of the time before a shift. However, I voted for "I shift when full pressure to the pedals is applied" because I have done so during times when it's simply unavoidable. This usually happens during MTBing.

I back off while shifting.

If I'm upshifting I tend to do it under load. When downshifting I tend to ease up a bit beforehand.

I upshift before a long flat section of ground that I want to go faster on.
I downshift before a hill, or when I'm tired. Not on the hills when possible... I'd rather walk up if I can't get up in the gear I was in before.

This is the way to do it.

What F1_Fan said, it becomes automatic and is not noticable with practice.
MadMan2k I shift constantly on hills as you tend to hit the bottom moving fast and then shift down as required and back up if the hill starts to level out, your missing out on alot of the enjoyment of seeing how steep a hill you can climb. It can give you a real sense of achievement.

Haha 'double clutching' on a bike!

It's the same thing though, you let off a little so the shift can go smoothly.

There are times... many times... in MTBing when things sneak up on you and you simply need to be in a lower gear and you need to be in it now. There's simply no time and no opportunity to let off the pedal pressure. That's why I don't like low-normal rear derailleurs. You can force a downshift in a high-normal RD but if you're using a low-normal then depending on how much tension is on the chain you may have to wait to get it up onto the gate in order to downshift and there's even a chance that the downshift will never happen. Additionally, the rate of downshifting is dependant on the rotational speed of the crank which in those types of critical moments is usually pretty slow as it is. While this is not as critical in an upshift-necessary situation, in a downshift-necessary one, it may mean that you never get the chance to complete the shift in time.

Let's see... 1987 Peugeot. Original drivetrain. Um, no, I don't shift under pressure.

Actually I don't think I've ever shifted under pressure. It just seems "harsh."

450lbs out of the saddle mashing on the cranks...my drivetrain simply screams when I don't take pressure off the drivetrain. At first through I would just randomly shift whenever *crunch*

I've twice broken my drivetrain, in a timespan of 2-3 years.