I would appreciate it if the board could double-check my shift pattern for me. I am just now figuring out that not all chain ring/cluster combo's shift sequentially, so please bear with me.

My old Fuji "10 speed" has a 52-42 x 14-28 on it with 27" wheels, which would give the following in gear inches:


(14 16 19 24 28)
52: 100.6 88.01 74.12 58.68 50.29
42: 81.24 71.09 59.86 47.39 40.62

Which would give a shift pattern of : (L=52, S=42, etc.)

L14, L16, S14, L19, S16, S19, L24, L28, S24, S28

That seem impossibly complicated. I am missing something here or should I just memorize that pattern? Are any of those gear combinations that I should avoid? I haven't noticed any cross-chaining on this bike.

Thanks

you're thinking about it way too much. imo, you should just try to minimize cross-chaining.

Replace the 42 with a 40, for a perfect 1.5-step pattern: 52-40/14-17-20-24-28. I use a slightly tighter version of the same concept: 50-42 / 14-16-18-20-23-26. Normally, one shifts by one rear cog at a time, which skips over one ratio, e.g. 4th gear to 6th. (Pattern is 1,2,4,6,8,10; 3,5,7,9,11,12.) To fine-tune upward by one ratio, you have to remember that the front shift covers three ratios at a time, whereas each step in back covers two. To shift up one gear, you either have to add 4 and subtract 3 (if coming from the large chainring) or subtract 2 and add 3 (if coming from the small chainring). Trust me -- these shifts become second nature after awhile.

Right, don't overthink it. If a "ten speed" gives you six or seven usable speeds, you're doing okay. When you're on the big ring, use the three smallest cogs in back to get 100.6, 88.1, and 74.1. Then drop to the small chainring and stay on the middle cog in back. Now you've got 59.9 (I'm rounding off), 47.4, and 40.6. That's six evenly spaced and easy-to-find speeds. That's all you need. Don't obsess about it.

For me on a double, the big ring is for cruising and light hills. I feel no compunction about cross chaining it up to 2nd gear (or down to 5th on a 6 gear cluster while in the little) when in the big ring. When I hit a hill (or am going slow enough), I'll put it in the little ring, go through all but the last gear, then upshift to the big one again once I get underway on the other side.

It's not like a car, and doesn't have to be all that linear - remember, the chainrings are the main changes - the freewheel/cassette is for tailoring it exactly.

In fact, on one of my bikes, I can't remember the last time I used anything BUT the big ring...but that one is a 48X38X26 triple. with 175mm cranks...and I'm a masher.

+1

Exactly correct.

When I am accelerating through the gears, I default to simple "crossover" shifting, e.g.:
42/20 to 42/18 to 50/18 to 50/16
The double-shift fine-tuning comes in at cruising speed, when I want something between, say, 42/18 and 50/18, where I have the choice of 50/20 or 42/16.

Don't even worry about all those numeric figures, just ride the bike. You'll find, after a few weeks, that certain gear combinations work best in certain situations, so you end up using them. Other combinations provide no advantage, so you ignore them. Period.

The closest I've ever bothered to worry about gear combinations and ratios is finding a comfortable combination for large chainring/middle freewheel cog while keeping my normal cadence on a flat road (leaving me a couple of cogs for fast downhill pedaling). Which gives me a speed of about 16mph in a normal, relaxed riding mode. Which keeps me happy. This got me to change all my large chainrings to 48t or 49t (depending on availability) from the original 52t. Other than that, I could care less. I'm too busy riding.

Yeah, don't look down, and don't think about it too much. If your feet are going around too fast, try a higher gear. Otherwise, try a lower gear. When in doubt, try a lower gear.

I didn't know people obsessed over gear ratios like this. I just pick the gear that gives me proper RPMs. It's not difficult.

That was super informative. So my best bet without changing my hardware will be to cross-shift on the middle cog, and occasionally use the two other ratios if I can't double-shift right away?


And John E., I would like to switch to half-step eventually, I'm just not sure that my shifting is up to it yet. Seems like a waste to use only 60% of my available ratios...

Thanks.

Think of the big chainring as a "high range" for tailwinds and downhill, and the small ring for climbing and normal cruising, with a bit of overlap.
Exceptions: I stay in the small ring if it looks like I won't be going fast for long, and stay in the big ring if it look like the upcoming hil is short & shallow.

Just as a point of clarification there are always at least 2 cross chained combos when you've got more than 1 chainring and a rear cassette.

Big Chainring/Big Rear Cog & Small Chainring/Small Rear Cog are crosschained combinations. Although depending on the chainline of your cranks (&derailleur capacity&chain length&other stuff) those combos can be used with varying levels of success.

Case in point I've got a TA crankset set up as a wide double 50/28. On the big ring there is enough chain and the chainline is close in enough to allow me to use all 5 cogs effectively. The Big/Big combo is still technically cross-chained but its useable.

Do you need the low gears for where you ride? In the flatlands where I ride I have a 42-52 and a 14-21 ultra six speed freewheel. Makes for closer stepped gearing.