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. 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