Old 08-04-12, 11:18 AM
  #2  
FBinNY 
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Join Date: Apr 2009
Location: New Rochelle, NY
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Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

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Originally Posted by mavic517
I have done many tire changes over the years. But the match of the MA-40's and Continental GP4000's are a nightmare to take off and remount. Why? Anyone had simular experience. Anyone have any solutions.........Please.........Thanks, Steve (mavic517).
I would hate to have to do a "one road change" with this combo. I'd call a tab instead.
Why is complicated, but the best advice is to simply avoid rim or tire models, or combinations that are too tight.

As to why, it's the confluence of a number of subtle variables. Over the years tire pressures have increased, while the desire or reduce weight means thinner wire or kevlar for the beads. This means increased stretch under load, so the bead has to start out more under sized to compensate. Also the change from the Endrich pattern rim with shoulders and a deeper center well to the current hook edge with a shallow concave center well means less room to shift the tire and create slack.

Put both together and the days of easy mount and dismount tires are gone. I shop carefully and look for deep rims, and stay with tires that I've found through trial and error to mount fairly easily. I'll sacrifice other criteria, like weight or max pressure to get good field serviceability, which for tires means the ability to change a tube on a cold rainy night, with half numb fingers.
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