Chr0m0ly 

79pmooney

I've been riding a long time and never did half step. Never wanted to. When I hit the 54/53/52-42 racing setup I felt I hit gold. Stopped racing and added an inside 28 tooth ring. Kept my close racing freewheel and added bigger cogs as FWs went to 6, 7, 8 an 9 cogs. My geared bikes are now

Fast road: 53-42-28 X any 9-speed casette from 12 to 28
Winter/rain/city/gravel: 52-42-26 X 14-28 7-speed. If I toured this bike, I would tweak it to 48-38-24 X probably the same 14-28 7-speed. Turning it to a 9-speed (on a different bike) and keeping the same range, just getting closer spacing would be first class.

I ride the vast majority on the middle ring using the whole FW/casstte. Loaded, I try to spend little time on the smallest cogs and use the big ring instead. I like having some overlap between the inner rnage and the middle range so I can do poor cross-overs briefly when hills level out to avoid double shifts.

Oh, edit: I forgot to ask what your dropout spacing is. (Inside measurement of the rear dropout flats or outside measurement of your rear hub locknuts. The bike measurement is usually a mm or 2 bigger to make getting the wheel in easy. Standard measurements are 120 (old 5-speed or narrow 6-speed, 126 (old 6-speed or 7-speed) and 130 (9/10/11 -speed). I'm guessing your bike is 126 but that is just a guess. It could be made to any of the standards depending on the year and widened later by an owner. If it is 126 and you want to keep it 126 (or 120 and you want to stretch it to 126), I'd go 7-speed unless there was a real reason to stay with the old 5-speed/old 6-speed chain standard. (You are in love with those old wide-standard chainrings?) 7-speed gives you more cogs, better spacing and is available easily in current manufacture FWs (and I assume cassettes though I really do not know). I'd seriously consider a 7-speed Phil Wood rear hub unless I was going to go with a cassette(see last sentence). Old 6-speed. 7-speed FW hubs have the weakness that they have long unsupported axle to the rightside and tend to break them. For loaded touring, I'd go Phil Wood there, not cheap. You can ride a busted rear axle until you remove the wheel. When you undo the quick-release, all your bearings will fall out if the hub is a loose bearing cup and cone hub.

Ben

John E

For what it's worth, my mountain bike currently has my only wide-range "touring" triple. I am very partial to either half-step-plus-granny or 1.5-step-plus-granny, to reduce the number of redundancies.

I used to run 3x7 with a freewheel: 48-40-24 / 13-15-17-19-22-24-26, but currently run 3x8 with a cassette: 48-40-24 / 12-13-15-17-19-22-25-28

The 24-40 shift cannot be done under load, but I am very old school in my shifting technique and never "power shift," anyway, and there is no reason not to spin on the granny before moving up to the cruising range. I use the 40 and the 24 offroad and the 48 and 40 on road.

I also really liked the narrower-range 3x6 I put on the Peugeot: 48-45-34 / 13-15-17-19-21-24, which a regular short-cage SunTour Cyclone II handled well. (The Simplex dropout of the 1980 PKN-10 can easily accommodate other makes of derailleurs quite easily.)

natterberry 

John E

The ratiometric steps are ideal, in my book -- right around 6 to 7 percent. This is similar to the popular old 49-46/14-16-18-20-23 combo. Back in my 2x5 days I ran 50-47/14-16-18-20-23 for flat land riding, swapping in a 42 to make a 1.5-step for hill work. I still use the latter, but with a 6-speed, which gives me a welcome 26T granny, similar to what you are proposing with your 28T.

Road Fan

We can talk a lot about what makes a good high gear and low gear, but that's not what makes a half-step. In a half step, the gear progression has no duplicates, and zig-zags across the gear chart. It has the rear cogs spaced by the same factor within the limits of feasibility. For example the jump from rear cog to rear cog will all be 16% as close as possible (I just picked 16% out of the blue, but it made a good example. The freewheel that results is (assuming 7-speed)

14 - 16 - 19 - 22 - 25 - 29 - 34. So one question is, can you buy a freewheel (need a threaded freewheel hub) or a cassette hub with this exact toothset? I think you can get a 14-34, but all seven need to match this specification.

The spacing factor is 1.16. To make the gear progression smooth, the ratio of the middle and large chainrings has to be half that, or 1.08. If for a decently high but not crazy 100 inch top gear, I need a 52 tooth chainring. It's also easy to buy. The matching middle ring is 48 teeth, also easy to buy. For the small ring, I assume a 16 tooth reduction, so you need a 32 tooth granny.

So you HAVE to find a 7-speed freewheel or cassette with tooth counts as I specified, AND you have to find a triple-capable crankset for 52-48, and you have to use those tooth counts. For the granny ring you can use what you want as long as it works. I think "16 teeth smaller than the next gear" is a workable target.

This gearing set gives you a gear range from 25.4" up to 100.3" (nearly 4 to one!), and has a gear inch increment from 3 teeth to 8 teeth from bottom to top gear. The intent is that you climb up a wall loaded with the kitchen sink starting in your 34-32, incrementally go up the granny range (like a modern bike) to the 22 tooth cog, then shift to 48 29 to minimize the chain angle. Then you alternate shifting back and forth to get 12 small 8% close-ratio jumps all the way up to top speed, 70 or whatever rpm in 52-14.

That's the real vintage half-step plus granny, and how to ride it. Keep a pretty constant cadence from the 48-29 all the way up to the 52-14 for a good road-riding range, and granny down to 25" climbing gear when you need it. I

It's based on fairly simple math, and I got all out of "Bicycle Gearing" by Richard Marr, a contemporary of Eugene Sloan. Frank Berto also told us all about this in Bicycling Magazine, in the late '70s and early '80s. I made it into an Excel spreadsheet program, where you can type your wheel diameter, desired top gear, desired rear cog increment, and the granny drop, and then Excel calculates the teeth, the ratios and some figures of merit for the freewheel and the shifting step sizes.

You still have to find or source the freewheel gearing that Excel says you need.

I can share the spreadsheet, but I only have it in raw Excel - I did not make it into something the user does not have to avoid, like Basic.

Algorithm guy, not a coding guy!

mountaindave 

Road Fan

I have to try out that GearCalculator program. I like tweaking on Excel, but clearly I can't display results well.

I'm glad to see that some of the suggested gearings are actually half-steps! 6 or 7 years ago that was not the case around here, or on iBob!

Road Fan

Yes, that would work!

mountaindave 

deux jambes

fietsbob

My 80's SBI Expedition came as a 48, 44, 28 I promptly changed that..

Back then..


















..

deux jambes

Chr0m0ly 

crank_addict

Beastly freewheel from Suntour circa 1984

beicster 

I have one of the 14-34 freewheels. Works great with an 8 speed XT derailleur on a short claw and with a Cyclone GT on a 32 mm claw.