A question about shifting

[szewczykm]

Shifting is a zig zag thing. I have three big rings, I try to live in the middle and on the big ring. I'm wondering if there's something I'm missing about how to smoothly get from lowest to highest and back down without the zig zag.

I'm up high on the middle ring and I'm anticipating moving to the big ring, but if I shift directly, it's like jumping up 5 gears (that's a guess). So I'm either pre-emptively downshifting the back gears (no longer creating power or bringing my cadence crazy high) and then shifting the front gears up to get back to about where I was in preparation for shifting up. Or the opposite is true when downshifting.

Are there any tricks? Like, If you're on the middle ring, don't go higher than "X" on the back gear. If you're at "X", shift to the big gear first, then keep shifting up if you need it.

Does that make sense?

[Mithrandir]

So what kind of cassette and chainrings do you have?


There are actually 2 types of shifting.

Half-step shifting, which is an older style of shifting and isn't very common today, is where the gears are set up so that you can shift up in the back, then up in the front, then down in front and up in back at the same time, then repeat. You won't see this configuration much anymore though.


More commonly you'll have 3 spread-out chainrings in front, and relatively close spacing in the back. So for example my bike is:

48/36/24 in front
11/13/15/17/19/21/24/27/30/34 in the back

So 90% of the time I'm in the middle ring, the 36 tooth chainring. When I'm about to hit a tough hill, I'll shift down in front and up in back three times at the same time; ie if I was in 36/21 (1.7 ratio), I would then shift to 24/15 (1.6 ratio). So in effect it feels like I've shifted down one gear using 4 clicks. This sets me up into a position where I won't have to shift the chainring while under full load; I can just actuate the rear derailleur for the duration of the hill.

Likewise if I'm shifting up a chainring, I'll shift the rear down 3 times, then the chainring up once.


The thing you have to watch out for is avoiding cross-chaining. It's not really a good idea to use the 11/13 with 24, or 30/34 with 48, or 11/34 with 36.

[Bill Kapaun]

It's the nature of the beast.

The amount of change can be somewhat modified by a cassette change.
Example, an 11-32 cassette will have much larger jumps than a 12-25.

You didn't specify what combination of cassette & chain rings you have or the type of riding.
IF you have minimal hills, a closer ratio cassette may be useful.

Other changes one can make are the chain ring sizes, although you can run into shifting problems.
On my 2 bikes, the largest rings are only 4 & 6 teeth larger than the middle ring.
I did that because of- my age, emphysema, bad knees etc. I simply found the "typical" 10 tooth jump pretty much rendered the large ring useless. Going to a much smaller "large" ring actually allows me to use it, giving me 2 gears I can use for tail wind situations or "cruising" situations where I can get a better chain line on 3-7 than 2-9.
Front shifting isn't as precise, but usable.

[CJ C]

you have tiagra like me. I don't know your gearing mine is 50/34 12-25 but this is what it do and it works. tiagra allow you to down shift three cogs at a time, so when going from small to big i simultaneous shift up to big and up three in the back, and it gets me to a close cadence. the trickier part is going from big to small, i shift front and back at the same time but the right shifter i have to tap it three times rapidly. i usually over tap or under tap, one day i will have it perfect.

[Drew Eckhardt]

Shifting is a zig zag thing. I have three big rings, I try to live in the middle and on the big ring. I'm wondering if there's something I'm missing about how to smoothly get from lowest to highest and back down without the zig zag.

I'm up high on the middle ring and I'm anticipating moving to the big ring, but if I shift directly, it's like jumping up 5 gears (that's a guess). So I'm either pre-emptively downshifting the back gears (no longer creating power or bringing my cadence crazy high) and then shifting the front gears up to get back to about where I was in preparation for shifting up. Or the opposite is true when downshifting.

Are there any tricks?

1. You can plan ahead. A slow shift is only important if you're headed up-hill and going to loose energy fast. Things may go more smoothly if you drop to an equivalent gear on a smaller ring (ex - 50x21 -> 34x14, this is simple arithmetic - 21/50 * 34 = 14.28 and 14 is closest) when you're nearing the end of a false flat which precedes a hill.

Down-hill nothing bad is going to happen if it takes a couple of shifter wiggles before you arrive at the next gear moving from the small ring to big-ring and delay applying power.

2. You can shift both derailleurs at the same time. Good derailleur setup makes dropping the chain shifting to smallest ring X smaller cog very unlikely and a chain catcher improves the odds to close to zero with a shift back on possible in the unlikely event you were shifting at the same time you were riding over a bump (like once in 4000 miles on a double where the small ring sees a lot of use).

Campagnolo shifters make this more pleasant since nearly all made over the last two decades will shift at least five cogs smaller with one thumb button press and three cogs larger with the front paddle.

For instance, when I was running 50-34 x 13-14-15-16-17-18-19-21-23 the next (not cross-chained) lower gear after 50x21 was 34x15. Pushing both thumb buttons got there.

50x19 was next after 34x14. That took simultaneous shoves to arrive at 50x17 followed by two more clicks on the right front paddle.

With a triple crank you can space the rings closer together for the same range and its less of an issue. With 50-40-30 x 13-23 9 cogs you could shift from 50x21 to 40x18 which is just two cogs away and 40x14 could be followed by 50x17 three cogs up.

[ChrisM2097]

So what kind of cassette and chainrings do you have?


There are actually 2 types of shifting.

Half-step shifting, which is an older style of shifting and isn't very common today, is where the gears are set up so that you can shift up in the back, then up in the front, then down in front and up in back at the same time, then repeat. You won't see this configuration much anymore though.


More commonly you'll have 3 spread-out chainrings in front, and relatively close spacing in the back. So for example my bike is:

48/36/24 in front
11/13/15/17/19/21/24/27/30/34 in the back

So 90% of the time I'm in the middle ring, the 36 tooth chainring. When I'm about to hit a tough hill, I'll shift down in front and up in back three times at the same time; ie if I was in 36/21 (1.7 ratio), I would then shift to 24/15 (1.6 ratio). So in effect it feels like I've shifted down one gear using 4 clicks. This sets me up into a position where I won't have to shift the chainring while under full load; I can just actuate the rear derailleur for the duration of the hill.

Likewise if I'm shifting up a chainring, I'll shift the rear down 3 times, then the chainring up once.


The thing you have to watch out for is avoiding cross-chaining. It's not really a good idea to use the 11/13 with 24, or 30/34 with 48, or 11/34 with 36.

If your in the middle chainring, there should be no problem whatsoever utilizing any/all of the rear cogs - and if you have the proper front derailleur, and it's been adjusted correctly, you won't get any chain rub, either.

I agree completely with regard to stepping the front up a ring, and the back 2 (or 3) cogs and vice-versa. When I approach a steep hill, I immediately drop to the smallest chainring and bring the rear down to a smaller cog to get as close to the current ratio as possible. On a wide-range cassette, like an 11-34, it's probably just 2 clicks. On a close-ratio cassette (like a 12-26), it's probably 3, maybe even 4 clicks.

[szewczykm]

OK, it really sounds like I'm not missing anything.

cassette	Shimano HG50, 12/27, 9-speed
cranks	Shimano Tiagra, 30/39/50

This is from the Giant web site. That's what's on my bike.

I just wasn't sure if I was missing some rule of thumb that made things easier. "No dummy, you can shift smoothly from low to high, it's 3 clicks on the back, one click on the front, 4 clicks on the back, one more of the front, and then the rest on the back.... everyone knows that!"

Thanks for your help!