I'm curious about the spreadsheet, too. Send it on! One of the lessons from testing tires was that the exact right pressure is not that important on bikes. It does seem to matter on automobile/truck tires, ruining gas mileage and overheating the tire causing spectacular explosions at highway speed, etc. I used to be very careful to inflate to the exact pressure marked on the tire before every ride, using a really accurate tire gauge, and now I don't worry so long as it feels OK.
I went to Ikea and got two really cheap bathroom scales to measure the weight distribution of my bikes (and for other projects), that's the kind of geek I am... On Thu, Apr 8, 2010 at 3:54 PM, Philip Williamson <philip.william...@gmail.com> wrote: > A fellow named Dave Adams derived a formula that approximates Frank > Berto's measured tire drop, and made an Excel file that uses it. > He's given me permission to pass the xls file on, if anyone besides > David wants it. > > You input your weight + gear, your tire size, and the percent of bike > weight on the rear wheel. > It gives you recommended pressures for front and rear tires. > > My sample of two (Quickbeam and low-trail Ross) showed that the BQ > figures for "normal" and "low-trail" rear/front weight distributions > were spot-on: 60/40 and 55/45 respectively, so the only difficulty > would be wrestling your loaded bike into the bathroom to stand on the > scale with it! > > So if you want to play with the file, let me know. > Philip > > > On Apr 7, 10:13 pm, jan_heine <hein...@earthlink.net> wrote: >> > Jan: would it be possible to develop an app that calculated recommended >> > tire pressure based on weight & tire size similar to the chart you >> > previously ran? That would be a wonderful tool to have on the website. >> >> The chart is available online (see our samples page)... >> >> http://www.vintagebicyclepress.com/samples.html >> >> Somebody could develop an app for it, I am sure. (Don't ask me - I >> already spend 50-65 hours a week putting together the next BQ...) >> >> However, the chart is only a starting point anyhow, and the hard part >> is measuring how much weight you have on each wheel. Once you have >> that value, going to the chart and figuring out the correct pressure >> for your tire is the easy part. >> >> Jan Heine >> Editor >> Bicycle Quarterly >> 2116 Western Ave. >> Seattle WA 98121http://www.vintagebicyclepress.com > > -- > 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. > > -- Bill Gibson Tempe, Arizona, USA -- 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.
