Noob gearing Question...

[10speed]

So I"m setting up for my first tour. I will be fully loaded for months of travel in the USA. My question is this:

Do I need a gear lower than 1:1?

I have a decent Crankset with 48-38-28 and I'm wondering what do as far as a cluster. The bike will be a 700c unit, fully loaded, and a noob on it. I commute everyday and am used to about 10-20 of riding daily so I'm not out of shape really, and I'm spry at the age of 25.

Should my big cog be 28 or 32? 

I really like clusters that dont have big jumps, for smoother shifting, but I really don't wanna walk up hill as a trade off.

Help me touring masters. Thanks in advanced for feedback.

[Cyclesafe]

Only you will know for sure.

Typical gearing is 48/34/24 with 11-34 assuming a 30-40+ load (including panniers).  Mountain bike gearing is preferred by some.

Soooo, you're best off with the largest cog cassette your rear derailler can handle.

Having said that, on my first cross country tour I never had to walk with a 50/39/30 with 12-25 cassette. 

[whittierider]

Do I need a gear lower than 1:1?

I'd say generally yes.  There aren't really any strict thresholds, and you may survive with a 30/25; but in high altitude with a load you'll find that that ridiculously low gear wasn't really as low as you thought.  The difference between a 28-tooth and a 32-tooth, percentagewise, is like the difference between a 7% grade and an 8% grade-- pretty minimal difference.  To get the closer spacing between gears though, you might be able to start with something bigger at the small end, like a 13 or 14 or even 15-tooth, maybe a 15-16-17-18-19-21-24-28-32 in a 9-speed, if you can get Harris Cyclery or someone else to build it up for you, or maybe the 14-15-17-19-21-24-27-30-34 they have at http://www.sheldonbrown.com/harris/k7.html .

I built up a really nice tourer at age 17 (in 1977) when I worked at a bike shop, and my boss had ridden accross the country the year before.  I asked him, "How low of a gear would you have liked to have?"  (Your "1:1" is a 27-inch gear and I was thinking of a 24.)  He said, "There were times I could have used a two!"-- an exaggeration, but the point was that there was no such thing as too low of a gear for some situations.  When you get down to about 16" (20/34), you might think walking is just as fast, but it would wear out your cleats, or be too slippery for walking on such a slope, or just not be as efficient.

[Tourista829]

There is an old expression, "When loaded touring, you can never go too low a gear."  I would replace the crank with 22, 34, 46. Rear cassette 11-34. 700c wheel, low gear 17.8 high gear 115.2. However, if you want a closer ratio, put a 12-27 Ultegra cassette. Low 22 High 105. Which should be fine  

[10speed]

What about 91.4 - 21.2 Gear Inches? I can achieve this by foregoing the Crankset I already have and buying a new Mtb Crankset (22-32-44). Then buying the tighter cluster (13-28) for optimal shifting.

Thoughts guys?? I really don't know squat. 

[whittierider]

What I put on the bike I referenced above did indeed top out at 44/13 with a 27" wheel, which comes out to about 91".  It was fine for me because I'm a spinner and I did spin it up to 45mph once drafting a truck.  Some will tell you it's not high enough; but if you're touring and you get going fast enough that you spin out, it's no big deal.  Just coast-- you'll still get there.  On my current road bike I hit 53mph a few months back in my 52/12 gear, and could have spun it up a tiny bit more if traffic had allowed.  As for the low end, the above referenced bike had 28/31, which is 24.4" with 27" wheels.  700c would be close enough that you won't feel the difference it gearing.  I think your proposed range sounds good, but front shifting will usually be better if the middle ring is more than the average of the inner and outer rings, like a 34 or 36.  (The average between 22 and 44 is 33, so the middle ring ideally will be more than 33.)

[10speed]

The average between 22 and 44 is 33, so the middle ring ideally will be more than 33.



If I run 44-34or36-22 will the chain want to drop when I push it to small chain ring?

I guess maybe I'll keep the crankset I have (Sugino 28-38-48) and just buy new rings for it.

Thanks again for all your help.

[whittierider]

If I run 44-34or36-22 will the chain want to drop when I push it to small chain ring?

Not if the front derailleur is adjusted right.  I didn't have any trouble with the 28-39-44 I referenced above.  For angle, the rear of the outside plate of the cage should be slightly farther out than the front of it.  If the limit screw is loosened enough for the crankarm to touch any part of the cage, it would be the rear tip of it.  Even a major professional self-help bike mechanics web page misses this.  For height, the outside plate of the cage should nearly touch the teeth on the big ring as it swings out, although a few work better if there's enough room to get a penny in.

Our tandem came with 28-42-52, and I had trouble with the front shifting for the whole first year, then someone on the tandem forum said you have to route the cable slightly differently from how Shimano says, in order to get enough movement between steps on the indexed shifter.  I did what they said and it never gave us any more trouble.  That was about ten years ago.  Here's what I ended up with:

There's a little nub at about 7 o'clock from the cable-fixing bolt on the derailleur, and Shimano says to put the cable to the left of it.  The suggestion to put it to the right of it is what they suggested, and fixed the minor but nagging problem.  And, BTW, we later replaced the 28T inner ring with a 24T for climbing the really steep (10%+) long stuff (since my wife is anything but a strong climber), so now we have 24-42-52, and it works fine even with the big jump from 24 to 42.