How about with a single speed? All shifts feel the same and the chain tension is constant. :-P
On Monday, January 12, 2015 at 1:50:25 PM UTC-8, Eric Norris wrote: > > With a three-speed hub, all the shifts feel the same, and the chain always > has constant tension. > > --Eric N > www.CampyOnly.com > CampyOnlyGuy.blogspot.com > Twitter: @CampyOnlyGuy > > On Jan 12, 2015, at 1:36 PM, Bill Lindsay <[email protected] <javascript:>> > wrote: > > Perhaps. In his Vol 2 No 2 BQ article, Jan hinted at the benefits of the > Nivex derailer *system*. He said that the benefit was that every shift > felt exaclty the same at the shiftlever, and he tried to attribute that to > the chain tension being constant. The implication then would be that on my > "normal" bike I shift even easier when chain tension is looser, but I work > harder when chain tension is tighter, but more importantly, I never shift > precisely because every shift is different? > > On Monday, January 12, 2015 at 1:20:55 PM UTC-8, Eric Norris wrote: >> >> Jan mentioned chain slap in the small/small combos (when chain tension >> would be lowest) as a major problem solved by constant tension. That >> suggests that normal “low” tension is “too low,” so perhaps somewhere >> between that and normal “high” tension? >> >> —Eric N >> [email protected] >> www.campyonly.com >> www.wheelsnorth.org >> Blog: http://campyonlyguy.blogspot.com >> Twitter: @campyonlyguy >> >> On Jan 12, 2015, at 12:46 PM, Bill Lindsay <[email protected]> wrote: >> >> I'm not doing anything in this project to attempt to achieve constant >> chain tension. Jan has mentioned multiple times that constant chain >> tension is much better, but he has left out a LOT of details to that >> theory, I think. Constant tension is better, but what value of tension? >> What procedure did he go through to optimize his chain tension? A >> "normal" derailer presumably has looser tension when you are in small-small >> and higher tension when you are in large-large. What tension range does a >> normal derailer have? Is it always too tight? Always too loose? Does it >> transition from too loose to too tight? What gear has the optimum tension. >> When it is too-loose, what performance are you losing? When chain tension >> is too tight, what performance are you losing? He hasn't developed that >> theory in any cohesive way, yet, that I've seen. >> >> Positron did not have dual cables. Positron had a monowire cable that >> would PULL and PUSH. There were special housing clips at either end and >> continuous housing all the way from the shifter to the derailer. You would >> pull the shifter to pull that wire, moving the derailer to a bigger >> sprocket. Then you'd push the derailer to push that same wire, which would >> push the derailer to a smaller sprocket. Shimano learned a TON about SIS >> housing from Postitron cable housing. >> >> >> >> >> >> On Monday, January 12, 2015 at 12:03:33 PM UTC-8, Eric Norris wrote: >>> >>> Jan Heine talks about making a similar custom derailleur for his Rene >>> Herse in the latest issue of Bicycle Quarterly. He says that having a >>> constant tension on the chain provides huge benefits in shifting and >>> overall performance. >>> >>> —Eric N >>> [email protected] >>> www.campyonly.com >>> www.wheelsnorth.org >>> Blog: http://campyonlyguy.blogspot.com >>> Twitter: @campyonlyguy >>> >>> On Jan 12, 2015, at 12:01 PM, Anton Tutter <[email protected]> wrote: >>> >>> Fair enough. And you KNOW I would never ask about #5, as I embrace DIY >>> and a hack culture in general. >>> >>> I was just curious why you would do this unless there was something >>> particularly nagging about your current derailleur setup. To do so out of >>> historical curiosity alone earns bonus points. >>> >>> Carry on. Interested to see the outcome. >>> >>> Anton >>> >>> >>> >>> On Monday, January 12, 2015 at 1:10:40 PM UTC-5, Bill Lindsay wrote: >>>> >>>> Anton, >>>> >>>> Can you be more specific? Why what? I'll take a guess at five >>>> possible things: >>>> >>>> 1. Why would you want to try using a springless rear derailer? >>>> Because they were popular during a very interesting period of cycling >>>> history, and disappeared basically by historical accident, and are now >>>> essentially forgotten. I'm curious at what was lost. >>>> 2. Why would you bother destroying a perfectly good derailer? Just a >>>> creative outlet. I think about bikes a lot. It's meditative and at the >>>> same time it is mental exercise. >>>> 3. Why don't you just ride instead of over-thinking things that are >>>> perfectly fine as they are? If I had more free time in the daylight I >>>> probably would. If I had less mentally idle time, commuting to and from >>>> work, maybe I'd come up with fewer ideas >>>> 4. Why make a non-linear shifter to complement your non-linear >>>> derailer, making the pair linear? Because in the lower end of my 9 speed >>>> cassette, I find the action on my downtube friction shifters very >>>> sensitive. All my overshifts and ghost shifts happen in cogs 1 and 2. >>>> Looking at the math, I found the geometry of my derailer demanded that >>>> sensitivity. I'm thinking maybe I can smooth that out and get fewer >>>> missed >>>> shifts and ghost shifts in the low gears >>>> 5. Why make DIY bike parts? Why don't you just buy what is available? >>>> Partially because I don't always find the industry at large is motivated >>>> by the things that motivate me. Partially because I'm a design guy and I >>>> enjoy putting my own fingerprint on my builds. Partially out of just a >>>> general curiosity and desire to explore ideas. I'm inspired by current >>>> and >>>> historical builders. One builder who particularly has inspired me is >>>> Charlie Cunningham. That's a guy who feels absolutely zero obligation to >>>> conform to what anybody else thinks a bike should look like or should be. >>>> 6. Why do you think a springless rear derailer is vastly superior to a >>>> normal derailer with a return spring? I don't, and never said I did. I'm >>>> just curious and like exploring. >>>> 7. How much faster do you expect to ride with this? Zero miles per >>>> hour faster >>>> 8. What are you trying to get out of this project? Grins >>>> >>>> Maybe you meant none of the above. Maybe you asked because you are >>>> pretty sure it's a stupid waste of time, which it might be. Add it to the >>>> long list of ways in which humans have wasted time. Maybe you meant >>>> something much different. >>>> >>>> On Monday, January 12, 2015 at 8:43:28 AM UTC-8, Anton Tutter wrote: >>>>> >>>>> Okay, but why? >>>>> >>>>> >>>>> >>>>>> >>> -- >>> 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 post to this group, send email to rbw-owne...@googlegroups. >>> <http://googlegroups.com/>com <http://googlegroups.com/>. >>> Visit this group at http://groups.google.com/group/rbw-owners-bunch. >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> >> -- >> 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 post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/rbw-owners-bunch. >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- > 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] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > Visit this group at http://groups.google.com/group/rbw-owners-bunch. > For more options, visit https://groups.google.com/d/optout. > > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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