h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Or more specifically, in what order would you go through the gears on a 15 / 18 / 21 gear bike?

Doesn't gradient come into this somewhere, or am I missing something?

I would say it has more to with selecting a gear that gives you a comfortable pedling speed, neither too hard nor too easy, to suite road.

Is this a question about ratios, i.e. when to change the front/rear gears?

There are gears on bikes nowadays?

not really, it's a vicious rumour.

I leave the left-hand gear (1-3) on 2, and move the right-hand gear (say 1-6) between 2 and 5. If I move outside this range, the chain's more likely to fall off.

Many of those gears shouldn't be used. Diagonal chains are bad for the bike, causing more wear. So for most diagonal gears, there's an equivalent gear with the chain in a straighter line. This means that an eighteen-speed bike doesn't actually have eighteen unique gears.

TRiG.

Yeah, I use to try and keep the chain straight on my last 18 speed bike.

Sorry can't help - my last bike only had 3 gears, and although I used my husband's for a while after I was married all I can remember is walking up the hills because with my son on the back I couldn't ride up them!

just waggle the gear selectors around a bit every now and then until you get a new gear then enjoy the thrill of the unexpected as you stand up cycle slower than a snail up a big hill or end up with your legs going supersonic in a low gear going down the other side.

It appears to have as much accuracy in it as any attempt to the learn the gears on my bike plus the added excitement of unpredictability.

Regardless of the method chosen, the chain will still fall off just when you think you've fixed it so it doesn't.

I knew that this wasn't a straightforward question!

What I was getting at was do you scroll through the large 3, 1-3 but at each stage of this scrolling through the back 5 1-5, or is it more complicated than even I'm making it sound!

That is does it go:-

1-1
1-2
1-3
1-4
1-5
2-1
2-2
2-3
2-4
2-5
3-1
3-2
3-3
3-4
3-5

Or am I over simplifying it?

Why all these gears?

PP

Mina, it sounds like the bike you used had a Sturemy Archer 3 speed gearing on center of back wheel. I have used them on many bikes, infact I look for bikes with them due to ease of looking after them and their high reliability. They are really good, I am no good at looking after derailer gears, the ones the openning post mentions, and being discussed now .

There are loads of gears because some are redundant. You shouldn't use the diagonal ones, as they put more wear on the chain.

TRiG.

Motors are good too.
Uhm... I mean electric ones of course.

~jwf~

Ah, like those you have to pedal a bit harder to charge up?

Trig-- That's a good answer, technically, but have you ever known any one who wore out a chain? In any case, the best quality chains have ball hubs in the links so the angle doesn't matter. A better reason for avoiding the angle is to keep the chain from falling off when pedalling hard. It happened to me once and I couldn't have children for many years afterward.

I find the easiest thing to do with multi speed bikes is to put the front gear in the middle one and select the back one as needed. In exceptional circumstances, up Everest say, you can move the front one. You're right, they're mostly redundant, but they do look good in the advertising copy.

I have a folding mountain bike that I keep on the back seat of my car. If they could only invent a greaseless chain.

I keep my front gear in third (of three) and just adjust the back one, only needing changing the front one as a last resort. This might have something to do with the gradients in Aberdeen.