Gearing question -

[Stephen Durfee]

Another list member recently asked a question "Which Front Derailleur option is best for a 38/24 front, 11-36 rear". At the time, I commented that my AR has a 38/24 front, that I often spin out on level ground and can only coast down hills, and that I have been planning to remove the chain guard and swap in a 46T front ring, to turn my double into a triple. But then I got to wondering, would I actually be better off making a switch in the back...

My 26" rear wheel is built around a Bullseye hub, with a 14-34 freewheel. The front wheel is brand new - a Rich-built dynamo with a Shimano hub. 

My question....would I be better off making a change in the front, going with a triple and the current rear wheel? Or, should I upgrade to a new rear wheel, with a hub cassette at 11-36? Here is my stab at basic math, which may or may not provide useful information

My current "big gear"  38÷14 = 2.71

with the added triple,   46÷14 = 3.28

with a new cassette and existing chainrings 38 ÷ 11= 3.45

I understand, of course, a new rear wheel would be a more expensive solution. My existing FD is a Shimano 105. I think it could handle the triple, but I haven't yet put it to the test.   Are there other factors to consider? 

[Ian A]

If you change the rear to a cassette hub, you will likely need to re-space the drop outs. I'm guessing your current freewheel hub is 126mm. Spacing.out to 130mm would be okay.

My opinion would be just to change the chainrings to give the higher gear. The older 5 ans 6 speed wide range freewheels lend themselves well to half-step gearing. If you have a triple crank maybe a 44/48 or 42/46 with a granny gear of 28. 

If you are just commuting and running around with bike (vs touring or randomneuring), I would be inclined to just put on bigger chainrings. Cheaper, easier, better!  My 26" wheel commuter had a 14-28 6 speed freewheel and I paired it with a 53/42 double and it was great like that.  I do enjoy mashing up hills on my commuter though. I consider it anaerobic training. Because the bike sees so much winter use, I decided to make it a single speed and like it even better now, but the above gearing worked well for me.

IanA Alberta Canada

[Garth]

A 24/36/46 triple will shift beautifully, and the 105 double, as long as it's not one of the oddball current types, should work just fine. I've used my 105 FD-5500 from 1999 on rings with 26/44/48 and 24/36/50.

I'm not a fan of adding more cogs(and the hub required) in the rear if the desired gearing variety can be done with a double or triple. I think 5-7sp FW's and hubs are terrific and highly versatile,.  I've even purchased more NOS FW vintage hubs(Suntour XC Pro and Specialized)  as I have a number of NOS 13-32 FW's, plus 14-34's(14/16/18/21/24/28/34) and 13-28's are still available as they have been for years. Try to find a 7sp cassette with those cogs, you won't. Try to find one of those, plus a 12t cog for 8 speeds, you won't. Sure you can go the Aliexpress route and make your own cassettes, which is fine if you already have the freehubs, but if don't already have the hubs , why bother ? Keep it simple.

[Patrick Moore]

If your current cogset is a freewheel it probably has no more than 7 cogs which limits the number of different gears.

How many gears you need depends on your own preferences: how high a high -- you've said you want a higher one and yes, 70" is pretty low; how low a low -- with the 24/34 I assume you want to keep a similar low gear of <20"; and how close you want the gaps between gears.

The possibilities also depend on how often you shift between chainrings and how much you like quick, smooth shifts.

The easiest option would be to swap the 38 for a 46 which would give a still pretty low 85" gear, assuming a more or less 26" tall wheel. The gap between this and the 24 is pretty big but it has been done, and it would be more doable if you don't use the 24 very much.

The next option is a triple with 46/36/24 which is pretty typical 7 speed triple chainring, tho' still on the low side with 26" wheels. Or -- my preference were I to use a triple with 5, 6, or 7 sp fw -- would be something like a 46/42/24 halfstep plus granny for closer ratios with higher top and same low.

But my overall preference would be to go whole hog and swap the hub for a modern cassette hub with 10 or 11 gears; yes, you'd probably have to spread the rear but it's not hard to spread a 126 mm OL rear to 130; in fact, I've often used 130 hubs in 126 steel frames, tho' it's a pain. With 3 or 4 more cogs you can (1) mix and match much more easily, (2) get a much higher top gear with the same 38 t ring, (3) get a similar or even lower low, and (4) get closer intermediate gears, and (5) do this without adding another chainring. 

I personally like "1X + granny" using 10 sp cassettes (might one day try 11) with something like a (note: this is for 700C wheels with fat tires, so about 29" tall, 3" taller than 559 wheels) 44/28 and a 14-28 10 sp (easy to customize cogs with a freehub) giving a high of ~90" and a low about 29", but with very close intermediate gears. Abandon 1-cog differences in the cruising gears and you can get just about any reasonable high and reasonable low with this sort of setup.

Patrick Moore, who has owned umpteen gadzillion 26" wheel road, all-rounder, and mountain bikes each with customized gearing. (My 2 current 26-ers are road bikes -- 29" for off road -- one fixed or with 2-speed IGH fixed hubs, 76" and either 68", 66", or 57" depending on hub) and the other with 3 speed fixed: 72", 65", 54" or 3 speed fw: 75", 65", 56"; 24.5" 559  X 28mm  and 25.6" 559 X 42 mm wheels respectively, but I've used singles, doubles, and triples on various 26" wheel bikes.)

--
You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/121edcd6-c2ae-4513-8f05-e37684b27c1cn%40googlegroups.com.

--

Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum

-------------------------------------------------------------------------------------------------------

Executive resumes, LinkedIn profiles, bios, letters, and other writing services

-------------------------------------------------------------------------------------------------------

When thou didst not, savage, know thine own meaning,

But wouldst gabble like a thing most brutish,

I endowed thy purposes with words that made them known.

[Patrick Moore]

Even quads! -- very briefly; Mountain Tamer Quad. Too finicky, IME.

On Sun, May 19, 2024 at 2:58 PM Patrick Moore <bert...@gmail.com> wrote:

... , but I've used singles, doubles, and triples on various 26" wheel bikes.)