On May 19, 8:54 am, CycloFiend <cyclofi...@earthlink.net> wrote: > > Ok. So, I think we were both making the same error, though on different > aspects of the problem. > > In your photo, you are showing the 6.5 _extension_ as a 6.5 _reach_ > > The extension would be at a 90 degree angle from the quill..
Yes, you are correct. On the Rivendell website it says, --- The 80 (wood stump pic) has an effect horizontal extension of 65mm... --- Due to that description and the way the image of the Dirt Drop is presented, I assumed Rivendell was making a distinction between the 'actual reach' (measured at a 90 degree angle from the quill) and the 'effective reach' (measured parallel to the ground), and that the 6.5cm figure was the 'effective reach'. After you posted your concerns about that figure, I abandoned Rivendell's description, and I went in search of the specs for the 80mm Dirt Drop elsewhere. Other websites say that the 80mm Dirt Drop has a rise of 35 degrees. With that figure, you can do the trig much more elegantly. Doing the trig reveals that the equivalent Technomic stem is 6.93cm long. So if Rene swapped his 80mm Dirt Drop for a 6cm Technomic, he would only be able to get the bars less than 1cm closer. Here are some revised pictures of how all that works out: http://www.flickr.com/photos/49416...@n00/4623159014/in/photostream/ http://www.flickr.com/photos/49416...@n00/4623159016/in/photostream/ http://www.flickr.com/photos/49416...@n00/4623159018/in/photostream/ The actual reach (measured 90 degrees from the quill) can be calculated, and as it turns out it is 6.55 cm, which is what Rivendell must be referring to with their 6.5cm figure. That means the 'effective reach' (measured along the horizontal) has to be less than 6.5cm, and in fact an 80mm Dirt Drop stem when mounted on a Bombadil has an 'effective reach' of only 4.7cm. -- 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.
