This is the issue of European, ISO --now thought of as Campagnolo-- standard , vs Japanese taper. The tapers are the same, but the starting points are different. Those who have found them incompatible do not understand how a wrench of such long experience as the late Sheldon could have found them otherwise, ever. One will not draw far enough on the other. The other will bottom out on the former.
It happens that the length of spindle you mention is that for a Campagnolo Record (or Chorus). Interesting that just a few days ago, in the CR forum on bikelist.org you will find as explanation for the slow adoption of aluminum cranks over steel ones on the pro circuit, the desire for steel's narrower tread, or Q, is an offered explanation. Not the same thing as your desire to work the most inboard chainring, but close. A few more words of caution on this confusion: French Stronglight has sourced cranksets from Japanese SR, so whether the crank follows ISO or JIS depends on the model. And, someone else here can say whether Japanese cranksets with 144mm bolt circles, associated with the old Campagnolo standard, always use the JIS taper spindle or the ISO. Harry Travis. On Nov 4, 1:18 pm, esaner <[EMAIL PROTECTED]> wrote: > I'm using a 9 speed cassette on a phil wood hub, so chainline isn't as > much of an issue. I would like the chainline to match up as close as > possible to the middle cog of the cassette, but based on my > measurements it will likely run closer to the next smaller cog. > > Any takers on defining a short taper bottom bracket (and low profile, > compact, etc) and explaining the reasoning behind it? > > -Eric > > On Nov 4, 12:02 pm, WillemJ <[EMAIL PROTECTED]> wrote: > > > I don't know what hub you will be using, but if by chance it is a > > Rohloff hub (it is an expensive bike, I understand), you should know > > that these suppose an mtb chainline, where the one and only chainwheel > > is in the outer position of an mtb chainset. So for a perfect chain > > line, the bottom bracket length should be the same as when you were to > > use the Sugino as a triple. > > Willem > > > On 3 nov, 20:18, esaner <[EMAIL PROTECTED]> wrote: > > > > Thanks. This is helpful. I hadn't read Sheldon's page on tapers, > > > though I already knew that this Sugino crank is designed for JIS > > > taper. Sheldon also doesn't address the terms short taper, low > > > profile, or compact on the page...frustrating. I had looked through > > > the bottom bracket size chart before, but it's not helpful since the > > > chart assumes the crank is being use as as triple, so it gives the > > > measurements I've seen elsewhere (anywhere from 107-115mm). > > > > It's good to know, Andrew, that you've already done with out any > > > problems what I'd like to do. I still find it odd, though, that these > > > terms are out there, but no one has really addressed them. Does the > > > term short taper simply mean that the taper is shorter, and thus the > > > crank bolt is in contact with fewer threads in the spindle? I'm not > > > sure why that would be necessary or beneficial. > > > > -Eric > > > > On Nov 3, 2:05 pm, Andrew Karre <[EMAIL PROTECTED]> wrote: > > > > > I've done this, actually, and it works fine. I've used a couple of non- > > > > PW 103 mm BBs w/ the XD as well as a a PW 103 with a Suntour XC Pro > > > > used as a double.I find 103 to be a handy BB for lots of double > > > > cranks. > > > > > AK > > > > > On Nov 3, 12:31 pm, esaner <[EMAIL PROTECTED]> wrote: > > > > > > I'm installing a Sugino XD500 triple crank on a new custom frame. I've > > > > > taken off the inner two chainrings and will be using the crank with > > > > > just the single 48t outer chainring. I installed a temporary bottom > > > > > bracket in the frame to measure how short of a bottom bracket spindle > > > > > I can use so as to achieve the smallest Q-factor (tread). The > > > > > temporary bottom bracket has a 115mm spindle. Based on my > > > > > measurements, I should be able to get by with a 103mm spindle. > > > > > > I would like to use a Phil Wood bottom bracket and their 103mm version > > > > > is listed as "short taper." I haven't been able to find a clear > > > > > definition of what this means. There is confusing information > > > > > especially on the Harrisy Cyclery web site, which seems to use the > > > > > terms "short taper" "low profile" and "compact" interchangeably when > > > > > describing bottom brackets of this type. Sheldon describes low profile > > > > > cranks here:http://www.sheldonbrown.com/cranks.html, and my > > > > > understanding of the term compact crank is that it refers to cranks > > > > > with 110/74 bcds. I'm also pretty sure that this has nothing to do > > > > > with difference between JIS and ISO tapers. > > > > > > So my questions (finally) are: > > > > > > What exactly is a short taper bottom bracket? (there is an obvious > > > > > answer based on its name...i'm looking for a more technical answer). > > > > > > What types of cranks can be used with it? > > > > > > What is the relationship between the terms short taper, low profile, > > > > > and compact? > > > > > > Can a short taper bottom bracket be safely and appropriately used with > > > > > a Sugino XD crank? > > > > > > Will a Sugino XD crank fit differently on a short taper bottom > > > > > bracket, such that I will need to re-think my measurements? > > > > > > Lots of questions! Thanks for all your help. > > > > > > -Eric --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Bicycle Lifestyle" group. 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