just as an aside to your aside, I recently did some hobbyist lathe work for our friend Joe Bunik, who intends to build a two-speed single-speed mountain bike. He had me modify a vintage crankset to yield a single 52-tooth aluminum chainring that can bolt to the Problem Solvers system of cassette spacers. I forget what his "other" cog size is going to be, but I think it may be a mirror, like 52/32 chainrings and 32/52 cogs, so he'll have a 52x32 high gear and a 32x52 low gear. I hope that doesn't spoil his reveal.
BL in EC On Tuesday, February 6, 2024 at 7:50:54 AM UTC-8 Patrick Moore wrote: > Just an aside, but I stumbled across this: a commercially available, > modifed single speed fw with *38 teeth. *Also available in a still > excessive (for a 1-sp fw) 28 t. > > > > [image: image.png] > > [image: image.png] > > > https://www.ebay.com/itm/256341921520?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D260344%26meid%3Dbe2f385cd1214fbd8f755967177959e8%26pid%3D101875%26rk%3D4%26rkt%3D4%26sd%3D296157601832%26itm%3D256341921520%26pmt%3D1%26noa%3D0%26pg%3D4429486%26algv%3DSimplAMLv11WebTrimmedV3MskuWithLambda85KnnRecallV1V2V4ItemNrtInQueryAndCassiniVisualRankerAndBertRecallWithVMEV3CPCAuto%26brand%3DUnbranded%252FGeneric&_trksid=p4429486.c101875.m1851&amdata=cksum%3A256341921520be2f385cd1214fbd8f755967177959e8%7Cenc%3AAQAIAAABYObhgc4Nk8%252BdtAwOww4FKLaj%252FQ5qqgDlQCuqZA43WcPFUWDERCUugbbOk7XQv0JXlBfqCg2xKF3WcPghxGMFw2oSlXvfExEaMYr7I7LmrHcP6czY1wIMt0ORyKiCWt95xldincyyBx3g%252BNDW%252B%252FhWUgTaBhK6xAm%252BJIbCOMehu%252BdwuOL9CsgIEdzXJ0407A2KnoQkkxd%252BfE557YZZlNfUYNlNqNAlRc%252FdNRI3MNqF8aELEQJMq%252BnvNt9O1Xa1UKu3RW0CkDa8JQvlXUNZSbLFWuVAeRyYpYRuNbHTVOX6C9zMdNw6RQjeBLo6WJYI3vLjOc%252Ff1jf6B5K3Ncu5DJZnB91jBcLNgLAflW%252Fe7MX6W5n223mlwXEfvtNU4vcjUipmdXEPZsMQ7nnQkiWJFyNmhZiuExvmkowHn0qDXR8G%252FVIXhP%252BoOrfOeIndzkLDZFUbcJ%252Bv8VsYXRbftGaKsqygNRw%253D%7Campid%3APL_CLK%7Cclp%3A4429486 > > On Tue, Feb 6, 2024 at 8:41 AM Patrick Moore <bert...@gmail.com> wrote: > >> Good point about very large gear gaps, and true that my riding does not >> generally involve very steep and very long climbs and that I generally >> prefer to torque than to spin. >> >> We all know that front derailleurs are capable of shifting 12-16 tooth >> gaps, my DA 7402 (?) fd shifts between the 44 and 28 just fine. Front >> shifts are slow compared to rear shifts but they're relatively foolproof, >> at least with friction shifting and with a properly set up fd. >> >> If you want a ~70" gear with a ~50" gear you could have a 48/34 double >> with an 18 t cog and get 72" and 51". (27" wheel.) >> >> Rear derailleurs will shift an 8t gap just fine; long ago I had a >> semi-half-step drivetrain, half-stepping the middle 5 cogs of a >> 13-15-17-19-21-24-32 7 sp cogset with the 13 used only with the big ring >> for downhills and the 32 with the smaller ring for steep climbs. The old, >> pre-indexing Shimano long cage rd shifted the 8 t gap fine. >> >> So, to get the same 72" and 54" gears with a 1X2 you could use that 48 >> with an 18 t and a 26 t and get 72" and 50". >> >> That leaves the question how to arrange a 2-speed, 18-26 t cogset. >> Cassette hub with spacers is one option, but I've been told that some >> 1-speed BMX freehubs can accept 2 cogs. And 3 speed freewheels are still >> available: >> >> https://www.amazon.com/3-Speed-16-19-22T-Thread-Freewheel/dp/B01M8GJV4O >> >> I wonder if you could find one or modify one to get an 8 t gap? >> >> Me, give me a SA TF hub, rarer than hen's teeth, which could give me 72" >> and 54" (71.5 and 53.6) with direct and 75% underdrive. >> >> >> >> >> >> On Mon, Feb 5, 2024 at 3:14 PM Bill Lindsay <tape...@gmail.com> wrote: >> >>> Patrick Moore claims to have "always" wondered: "I've always wondered >>> what advantages a 2X1 has over a 1X2 if you are going to use derailleurs" >>> >>> Can you be more specific about this 1x2 with a rear derailleur that you >>> are comparing? Is this a bike you have? Have had earlier? Saw in >>> person? Or are these 1x2 and 2x1 machines just imaginary build concepts? >>> >>> Anyway, in my opinion, I think 2x1 would be a lousy choice for Patrick >>> Moore. A Patrick Moore 2-speed is a bike that has two gears that are >>> practically the same. Like a 74 and a 66 or something like that. >>> Achieving two gears that are basically the same would be easy with a two >>> speed freewheel and a rear derailleur. A Patrick Moore 2 speed is for 12 >>> mile grocery runs or chasing down young 'uns on the MUP, or grunting up the >>> tramway hill at 30RPM in with a devout and severe mindset of >>> self-flagellation. >>> >>> The place where a 2x1 gets more interesting, in my opinion, is when you >>> want two gears that are not right on top of each other. For example, a 70+ >>> inch gear for the flats and a <50 inch gear for actual climbing (or even >>> <40). There's no 2-speed freewheel off the shelf that has like an 18 and a >>> 26T cog. Even if you built something, or cobbled something on a cassette >>> body, getting a rear derailleur to shift that would be tough. A Patrick >>> Moore two speed in the front would look like a half-step. Like maybe a 18T >>> cog with a 48 and a 45T ring, plus a tensioner. >>> >>> Note that NONE of the Riv staff 2x1 or 3x1 builds has the ultra narrow >>> spread of a Patrick Moore bike. It reminds me of how I would give a >>> 60-second crash course on shifting at the bike shop when every single bike >>> was a 3x7 mountain bike: I would tell them that the terrain should make it >>> obvious which chainring you are in: Middle ring for just noodling around. >>> Big ring for going fast after you have a good head of steam. Granny ring >>> for going up a steep hill. After that obvious choice, then shift the rear >>> on feel. Little easier this way, little harder that way. A 3x1 is exactly >>> the same, in my view, with no rear derailleur. >>> >>> So, in short, the thing that you've "always wondered" is that a 2x1 or >>> 3x1 has no advantages for the very narrow build type that you tend to >>> feature. You've got your Patrick Moore build envelope all figured out. >>> That's my opinion anyway. I'm looking forward to putting my new-to-me 3x1 >>> Rivendell through its paces, starting maybe in March. I have some >>> self-flagellation of my own to get done before that. >>> >>> Bill Lindsay >>> El Cerrito, CA >>> >>> On Monday, February 5, 2024 at 9:55:20 AM UTC-8 Patrick Moore wrote: >>> >>>> I've always wondered what advantages a 2X1 has over a 1X2 if you are >>>> going to use derailleurs -- the 2X1 requires a FD and something like a RD >>>> while the 1X2 requires only the rear one -- but for ss sans derailleur >>>> some >>>> people say that front shifting is easier than rear shifting. Not for me, >>>> though. >>>> >>>> Am eagerly awaiting the close ratio Silver Rivendell IGH (with >>>> proprietary wingnuts). >>>> >>>> On Mon, Feb 5, 2024 at 10:51 AM Mathias Steiner <mathiass...@gmail.com> >>>> wrote: >>>> >>>>> Bill said >>>>> >> I think the 2x1 or 3x1 concept around the Roaduno is brilliant. >>>>> >>>>> ... A 2x1 would give me all the complexities of a rear derailleur, >>>>> plus the poorer shifting of a front system. >>>>> >>>> >>>> -- >>> 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/280e39f1-3d14-4f7e-b865-02b474952076n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/rbw-owners-bunch/280e39f1-3d14-4f7e-b865-02b474952076n%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.* >> > > > -- > > 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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