BobB
Joined: 13 Jan 2004
Posts: 171
Location: Columbus, OH3/21/13 7:47 PM |
Riding wider 25mm (really 27mm) tires -- what pressure?
After mounting wider 25mm tires, I used this spreadsheet based on Frank Berto's research to determine the appropriate tire pressures:
http://www.biketinker.com/tire-pressure-calculator/
I was surprised how low the recommended pressures were.
The measured width of my Michelin Pro2 25mm tires is 27.6mm (my 25mm Gatorskin and Serfas Seca tires are about 26.5mm). I hope actual measured width is what the spreadsheet expects. At 27mm and 190# for bike and rider, the spread sheet says 81lb Rear and 65lb Front. I use a little more, 90lb rear and 70lb front. So far after about a year of riding, no pinch flats. I think I get a great ride. Riding on Ohio's chip and seal roads is much nicer. I don't ride fast enough (LOL!) that the additional frontal area of the wider tires makes any difference to my top speed. I don't ride aggressively and most of those miles were on my commuter, which has Mr Tuffy tire liners that also might help prevent pinch flats.
One note about this spreadsheet. Apparently all users are using the same spreadsheet at the same time. I believe I have watched values on the spread sheet change with no input from me. Make sure your inputed values are the same before you write down the result.
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