on 5/18/10 11:36 PM, CycloFiend at cyclofi...@earthlink.net wrote: > on 5/18/10 9:57 PM, happyriding at happyrid...@yahoo.com wrote: > >> On May 18, 8:38 pm, CycloFiend <cyclofi...@earthlink.net> wrote: >>> >>> I'm not quite following your math (geometry?) on this. When they describe >>> the horizontal extension as 65 mm, wouldn't that be the just 5 mm longer >>> than a 6 cm Technomic stem? >>> >> >> If you have two stems: an 80mm Dirt Drop (with 65mm extension) and a >> 6cm Technomic, it will be impossible for you to get the bars in the >> same spot--no matter what you do. Additionally, you will never get >> the bars to be within even .5 cm of each other. > > That's the statement I'm not following. > > If the extension is 6.5 cm on the Dirt Drop stem, and the extension is 6 cm > on the Technomic, the former will be .5 cm closer with the bars at the same > height. > > The extension is the measurement from the bolt center, which is the same as > the center of the headtube. Whether you get there with an up-angle stem such > as the DD or the "7" style of the Technomic doesn't matter.
Now, y'see, I shouldn't be making late posts when fighting a head cold... It finally occurred to me why the 6 cm "7" style stem doesn't have a 6 cm extension for the purposes of this comparison. Now, it did take me putting pencil dots on the 12 cm Technomic I'm not using and measuring, but, hey, sometimes I'm a visual learner... I was definitely confusing the idea of "Reach" and "Extension". Made me dig through my ref's and refind this link: http://www.habcycles.com/fitting.html and I'll work through this when my brain is better.. http://mathforum.org/library/drmath/view/53925.html oh, and though this is set up more for threadless (i.e. spacers) here's a stem calculator (allows comparison for two sizes) - http://www.brightspoke.com/t/bike-stem-calculator.html? - Jim "...bed!" -- Jim Edgar cyclofi...@earthlink.net Current Classics Bicycle Photo Gallery - http://www.cyclofiend.com/cc Cross Bike Photo Gallery - http://www.cyclofiend.com/cx Single Speed Garage Photo Gallery - http://www.cyclofiend.com/ssg Working Bikes & Practical Hardware - http://www.cyclofiend.com/working Work Shops of the iBob's - http://www.cyclofiend.com/shop Gallery updates now appear here - http://cyclofiend.blogspot.com Send In Your Photos! - Here's how: http://www.cyclofiend.com/guidelines "That which is overdesigned, too highly specific, anticipates outcome; the anticipation of outcome guarantees, if not failure, the absence of grace." William Gibson - "All Tomorrow's Parties" -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
