This is very interesting since it uses a *stock* cassette. Must investigate further.
I like the 45/42 option. Can one still get 45 t rings? I used to get odd-tooth-count sizes in 110 bcd from Sugino 30 years ago — I used both 47/44 and 48/45 combos (25” wheels) but I’ve not looked since. On Sat, Jul 26, 2025 at 12:05 AM Shannon Menkveld < [email protected]> wrote: > The Shimano 9-speed 12-36 is a half-stepper's dream cluster: > > 12-14-16-18-21-24-28-32-36 > > Makes for a 7-9% half step with any of: > > - 48/45 (107 - 33.4 inches) > - 45/42 (100" - 31.2", probably what I would build. 45t chainrings are > limited to 110 bcd, so far as I can tell.) > - 42/39 (29" - 93.6", best bet for a 130 or 135 road crank.) > > Similar logic applies to 1.5-step and 2.5-step setups. > > The SRAM, but not Shimano, 10-speed 11-36 just adds the 11 to the existing > progression, giving a 112 inch high gear, at the costs of going 10 speed. > Not worth it, IMHO, unless I was standardizing all my bikes on 10. (Which I > wouldn't do, the price jump from 9 to 10 speed parts is still pretty huge.) > > You do have to use a road double front derailleur, or an older triple > that's marked "for half step gearing" or somesuch. I know there's a Deore, > and there are probably others. They don't have the dropped and profiled > inner cage plate, which will hit the middle ring when you're upshifting. I > use a Suntour AR, and it works great. > > I built my HS+G because > > - I was converting a bike that I bought as an un-Drewed single speed > back to geared drive. > - I needed low gears > - I was cash broke and parts middle-class > - I had a NIB 1980 Suntour Superbe rear derailleur that I really > wanted to use, but its max cog and chainwrap are specc'd at 23t. > - All my freewheels were 1x-26 clusters > - I'd always wanted to try a half-step. It appealed to me, primarily > because duplicate gears offend my sense of rightness. > - I was broke > > It works a treat. The ~7% gaps are perfect, especially on the flats and > into the wind. And, yes, with the Rivendell Silver D/T levers, it's a lot > of fun to shift. (The way I do it is, from a stop, ride up on the 42 (~14% > jumps, not a problem when you're accelerating,) until I'm just spinning > just that little bit too fast. Then upshift the front and iBob's yer uncle. > > The Peugeot PKN-10 has 48/34 x 12-14-16-18-21-24-28-32, for a 28.4" - 117" > 2.5-step "alpine" setup. > > The GT Karakoram will get 42/34/22 x 12-14-16-18-21-24-28-32, for a > 92.1"-18.1" 1.5-step + granny. (I may try the double version on the > Peugeot, as I think it will make the big ring even more useful.) > > --Shannon > On Friday, July 25, 2025 at 7:27:50 PM UTC-7 Robert Tilley wrote: > >> Brompton 6 speeds are basically half-step gearing. Three speeds on the >> internal hub with two cogs making 6 gears spaced about 25% apart. I’ve >> never used a true half-step. >> >> Robert Tilley >> San Diego, CA >> >> >> Sent from my iPhone >> >> On Jul 25, 2025, at 7:13 PM, Ted Durant <[email protected]> wrote: >> >> On Friday, July 25, 2025 at 12:57:43 PM UTC-5 Patrick Moore wrote: >> >> Shannon’s post reminded me of the pleasures of half step gearing... >> Does anyone here use a half-stepped system? >> >> >> This is a timely post for me. I recently took delivery of a new Chapman >> "light touring" bike and, as part of the process of deciding what did that >> bike want to be, I worked hard on a half-step gearing setup. It turns out >> to be impossible to buy a cassette that works for that, so I cobbled >> together something from Alibaba and spent some time with it on a test >> bike. I'm pretty sure I'm as nerdy about gearing as anyone, and I have the >> Excel workbook to prove it. I am supportive of the idea of half-step and I >> wanted it to work. In practice, though, I didn't find it worked well for >> the riding I mostly do around here. >> >> My take on it is that, if you are limited to 5 or 6 cogs in back, then >> half-step makes sense for all the usual reasons. Like Shannon, my >> preference is for a 15% step between gears, just enough to be meaningful, >> not so much that I have to ride at a cadence that's outside my comfort zone >> between gears. The Shimano 9-speed 11-32 cassettes are >> 11-12-14-16-18-21-24-28-32, which is average steps of 14% from the 12 to >> the 32, with a minuscule 1.4% standard deviation among those steps. The >> 11-12 jump is pretty much a toss - okay, fine, I can turn it to 11 for that >> little extra more at 50kph. >> >> I also understand the idea of efficiency and not having any duplicate >> gears, but in practice my 2x9 is an 8-speed transmission with a two-speed >> transfer case and one extra gear at the top. I'm normally in the big ring, >> shifting to the small ring when facing a sustained climb of, say, 5% or >> more. In either ring I've got lovely, consistent 12-15% jumps between each >> cog. What I really care about in front is that the change between the big >> and small ring is around 30-35%, big enough to get me to some appreciably >> smaller gears, but not so big that it's a massive change in RPMs when I >> shift. A 42/26 combo is a giant 48% change (I use log-differences...), >> which is way too much for me unless I first shift the rear at least 2 cogs. >> Minimizing shifts is another form of efficiency, and I'm happy to use the 9 >> cogs in back to improve that aspect. I've learned not to grind my gears >> (hah) over duplicate gear combinations. >> >> With 11+ cogs in back it opens up another style of gearing, which I have >> on one of my Sams. The small part of the cassette is 1-tooth jumps, 11-15; >> the large part is 2+ jumps, 11-15%, average 13%, stdev 1.3%. This creates >> something of a 4-range gear setup - 1) big gears/small jumps; 2) medium >> gears/medium jumps; 3) medium gears/small jumps; and 4) low gears/medium >> jumps. Well, that's the theory. In practice I end up using it as simply >> high gears/low gears, and I tend to spend most time in the bigger 2/3 of >> the cassette. >> >> Ted Durant >> Milwaukee, WI USA >> >> -- >> 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 [email protected]. >> To view this discussion visit >> https://groups.google.com/d/msgid/rbw-owners-bunch/6577996b-ec92-4ffa-98a2-1c5748ab947en%40googlegroups.com >> <https://groups.google.com/d/msgid/rbw-owners-bunch/6577996b-ec92-4ffa-98a2-1c5748ab947en%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> -- > 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 [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/rbw-owners-bunch/8a9eb0da-3595-4b74-86d9-6c3236aca823n%40googlegroups.com > <https://groups.google.com/d/msgid/rbw-owners-bunch/8a9eb0da-3595-4b74-86d9-6c3236aca823n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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, k**now thine own meaning,* *But wouldst gabble like a** thing most brutish,* *I endowed thy purposes w**ith words that made them known.* -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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