Thanks Ray. That seems to go along with what Sheldon writes here: http://www.sheldonbrown.com/cranks.html.
And if PW only offered a given length JIS tapered bottom bracket as either standard or low profile, I would guess that they were using the term "low profile" as a recommendation that spindle's that short only be used with modern, flare style, non-track cranks. However, their 108mm bottom bracket is listed in both JIS (standard) and JIS low profile - and Campagnolo as well, which suggests a technical difference between JIS standard and JIS low profile. I think I'll send my question directly to PW to see what their answer is. I'll post any replies that I get. -Eric On Nov 11, 9:42 am, RayVarella <[EMAIL PROTECTED]> wrote: > I believe that "low profile" refers to most modern cranks. > Crank arms used to be straight and the arms were parallel and the pedal > mounting holes were in the same plane as the crank mounting bolts. > > Modern low profile cranks have some flare to the arms, they are no longer > straight (save for some track cranks). > The way the arms flare out means that the pedal mounting holes are further > outboard from the crank mounting bolts making it possible to use a shorter > spindle on the bottom bracket than would be possible > with straight arms. > > Ray > > On Tue Nov 11 6:06 , esaner <[EMAIL PROTECTED]> sent: > > > > >Travis, your still missing the point, so perhaps there's more > >reasoning there than you think. > > >I understand the concept of asymetric bb spindles, the ability to > >laterally adjust PW bottom brackets, the implications of shorter bb > >spindles on clearance for cranks/chainrings, and the difference > >between ISO and JIS taper. > > >What I don't understand is the PW bb label: JIS low-profile. > > >I don't understand it, because it is distinguished from standard JIS > >and from what PW refers to as Campagnolo, which I know to be ISO. To > >confuse the matter further, at various places on the Harris Cyclery > >web site, the terms "short taper" and "compact" are also used > >interchangeably to distinguish that same bb that PW calls JIS low- > >profile from other standard JIS or ISO tapered bb. > > >A complete and accurate answer to my query will use and define the > >terms JIS low-profile, short-taper, and compact, and will distinguish > >them from ISO and standard JIS. > > >On Nov 10, 4:24 pm, "[EMAIL PROTECTED]" [EMAIL PROTECTED]> > >wrote: > >> This isn't a matter of reason, but of specification Rereading > >> your first post, I see that you would prefer to be asymetric on the > >> spindle, because you wish the narrowest tread or Q. If you put on a > >> short spindle both crank arms will mount closer, and the left crank > >> arm may hit the chainstay. Tthat would be true here for a bike with > >> just 1/4 inch =6mm clearance between left chainstay and the pedal end > >> of the left crankarm. > > >> Phil (PW) bottom brackets can be adjusted laterally in their cups. > >> Another, less expensive approach is given here: > > >>http://house-of-yes.com/phil-wood-y-bottom-bracket/ > > >> On Nov 7, 12:01 pm, esaner [EMAIL PROTECTED]> wrote: > > >> > I'm not convinced that this is an issue of ISO vs JIS. If it is, why > >> > does Phil Wood list three types of 108mm bottom brackets: JIS low > >> > profile, JIS, and Campagnolo? See the list > >> > here:http://www.philwood.com/SpecStainlessBB.htm > > >> > It appears that there is a difference between ISO/Camagnolo and Low > >> > Profile/Short Taper/Compact. > > >> > Phil Wood's explanation is this: > >> > Campagnolo = ISO Taper ("94 & Later Campagnolo cranks > >> > JIS =JIS & older non Low Profile cranks ("93 & earlier Campagnolo) > >> > JIS Low Profile =JIS Taper (Low profile cranks) > > >> > There has yet to be a voice of real reason on this question. I would > >> > be great to have an answer that adressess the question of the > >> > difference between Low Profile and Campagnolo, and the difference > >> > between JIS and JIS Low Profile/Short Taper/Compact. > > >> > Kudos ahead of time to the person that can do it. > > >> > -Eric > > >> > On Nov 7, 11:32 am, "[EMAIL PROTECTED]" [EMAIL PROTECTED]> > >> > wrote: > > >> > > 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. 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/bicyclelifestyle?hl=en -~----------~----~----~----~------~----~------~--~---
