One thing to consider when shifting closer spaced cogs is the greater precision of newer rear derailleurs compared to older ones. I was surprised at how badly the 8 sp XT rd shifted compared to the 9 sp era LX, and my brother tells me that 6 sp era Shimano rds are even less precise.
When I first installed the XT (because I didn't like the reverse pull of the LX) I was convinced it was worn because I could not get it to sit smoothly on certain cogs, at least without a lot of fiddling with the shifter. I later learned the technique and, with that, it shifts fine, but the LX was definitely more precise. Cheapest 9 sp SRAM chain, silvers. That said, I had no problem with an 8 sp Dura Ace rd on Am Classic and Shimano 10 sp cassettes -- using a Connex chain. On Sat, Aug 25, 2012 at 5:46 AM, Michael Hechmer <[email protected]> wrote: > Out riding on my Rambouillet yesterday, which has Silver DT shifters, I got > a ghost shift. This happens rarely, every 35-50 miles or so, enough that I > usually just chalk it up to user error. But this time I got to thinking > about why this works so well for me while others have so much difficulty. > > I have four bikes with Silver shifters, my Ram and old racing bike have DT > shifters, and two touring bikes, an Ebisu and an old Trek have BE shifters. > I realized that I do seem to have some more issues with the touring bikes, > ghost shifts every 10-15 miles. This is annoying, but not enough for me to > want to give up either 9 speed or friction. For a long time I thought the > difference seemed to be in where the shifters were located and wondered if I > got more cable stretch, and noticed that the BEs have a tendency to loosen > the D ring a bit. But yesterday I realized that the placement of the > shifters has nothing to do with the difference in performance. > > To make 9 speed friction work I always use good cassettes, good chains and > good deraillers. All four bikes have hi end cassettes and conex 908 chains, > kept clean and replaced when needed. The difference in performance that I > am seeing is in the derailler. The two bikes with DT shifters have compact > doubles and relatively short range deraillers - Ultegra 6700, which is a > short cage derailler designed for CDs & the standard 6600 derailler designed > (I think) for 29 teeth. Both of these work well across the 31 & 29 teeth of > the two bikes. The touring bikes have triple cranks and a 38 tooth range, > which of course requires a derailler with a much longer cage. I use the > Ultegra racing triple derailler on one and a mid length Centaur on the > other. These cages are much shorter than the mt bike deraillers, like the > XT, and very long cage Centaur, which are designed for 45 teeth or more. > It seems obvious to me as I think about it that as the cage gets longer the > possibility of mis-allignment gets greater, which is what causes ghost > shifts. > > So, it looks to me, that to make friction work well with 9 speed the bike > should have good components and the shortest cage that will work with the > gear range needed. I have found that the mid range deraillers will handle > my set up (48/34/26 & 12-28) with some occasional failures. I expect that > riders who want an even wider range will have increased ghost shifts if they > use friction. > > Michael > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/rbw-owners-bunch/-/xkgqZl_fDwQJ. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/rbw-owners-bunch?hl=en. -- "Believe nothing until it has been officially denied." -- Claude Cockburn ------------------------- Patrick Moore, Albuquerque, NM, USA For professional resumes, contact Patrick Moore, ACRW http://resumespecialties.com/index.html ------------------------- -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
