Multi-part question with an even more involved answer. Easy stuff first: Phil Wood is JIS taper TA and Stronglight are ISO taper Now for the involved part, and I will preface this with: my results differ slightly from Sheldon's/Trautmann info. My experiment: 1. A known ISO crankset (Stronglight 104) 2. A known ISO spindle (matching Stronglight 118.5 c.'80) 3. A Campy pre'94 taper spindle (NR 114.5) (those after '94 & OT are ISO) 4. A known JIS (cartridge) spindle Shimano UN-73 118mm Now since my spindles were of a different length, and unfortunately threading as well (which was the original cause for this madness), the only way I could make a comparison was to measure the q-factor (off the bike and by placing the arms across rather than opposing) on each spindle, and adjust the results by the difference in spindle lengths. My results are as follows: ISO resulted in 3mm less q factor than old Campy; which is another 3mm less q factor than JIS. So to maintain the same chainline for an old ISO crankset on a modern JIS cartridge, you just buy a 6mm shorter spindle than the ISO spec, correct? Not so fast, my friend. The older spindles were [generally] offset to the drive-side, and modern JIS cartridges are [usually] symmetrical. So for the adjustment calculations. Take your ISO spec (mine was 118.5mm), add the offset (mine was +2mm), then subtract the 6mm to find an equivalent symmetric. eg. (118.5mm+2mm)-6mm = 114.5mm, so the closest would be 115mm. Since I had an older crank, with presumably a slightly enlarged hole, and I held the properly threaded 118mm JIS in my hand, into the frame it went. My chainline "theoretically" should have been out (118-114.5)/2=1.75mm, but in actuality ended up out about 1mm. Close enough. Where I notice a difference is in the non drive side arm, as it "sticks out" a few extra mm due to the non-offset, and it widens my "q" those few mm as well. The 104 was a narrow q anyway, so I'm happy.
Jim Carter "the French metric manufacturing standards were right" living way above my means in Mountain Brook, suburb of Birmingham, Alabama United States of America
To: Classic Rendezvous <classicrendezvous@bikelist.org> Sent: Sat, February 13, 2010 11:00:21 PM Subject: [CR] Spindle for TA 3-pin crank ?
Ahoy !
Some TA spindle/crank questions -
Can someone point me to a source of information so that I may determine the nominal spindle length for a TA 3-pin crank (double)? English bb shell.
Is JIS taper a match for the TA 3-pin? My recollection of an old CR list discussion is that JIS will fit the TA cranks but may place the crank farther out; therefore, one may want to use a JIS crank 2mm shorter than the originally spec'd TA spindle. Can anyone comment on this? (Oh, ditto for Stronglight).
If JIS will fit TA then, Phil Wood should fit TA because Phil Wood is JIS? Can anyone confirm ?
Thank you.
Richard Cielec
Chicago, Illinois; U.S.A.