Hybrid Bicycles - Largest tires possible on Trek 7.2 FX?

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blackstripes
09-24-09, 08:06 AM
I bought my wife a Trek 7.2 FX last year and she loves it. I took her on a relatively beginner level single track last week and she had a blast, but the ride was a bit rough. Currently the bike has the stock 700x35c tires on it, and I am looking to throw something with more air volume and run it at a lower pressure to give her some more cushioning. I realize there isn't a whole lot of room in the front and back for a really large tire, but wanted to know how big some of you have gone. Could I fit a 42 or 45? Any specific tire that works really well? Thanks!

blackstripes
09-24-09, 06:25 PM
Crickets.... :)
mikeybikes
09-24-09, 06:30 PM
You need to measure how much distance you have at all points surrounding the tire and make sure there's enough room.

A 700x45 tire is going to be ten millimeters wider than a 700x35 (theoretically, if all manufacturers sized the same)

So, to fit a 700x45 make sure there's at least 5 millimeters on each side of the tire. Preferably more.

2wheeldeal
09-24-09, 06:46 PM
http://sheldonbrown.com/tire-sizing.html#width

This lets me kvetch about rim dimensions - like, why aren't they available somewhere? Matrix 750 rims aren't sold outside of Trek, so you'd have to pull out the caliper, or ruler, or something.
mikeybikes
09-24-09, 07:22 PM
http://sheldonbrown.com/tire-sizing.html#width

This lets me kvetch about rim dimensions - like, why aren't they available somewhere? Matrix 750 rims aren't sold outside of Trek, so you'd have to pull out the caliper, or ruler, or something.

Oh no, the dreaded ruler! You don't have one of those lying around?

Actually, check the labels on your rims. On my stock Alex rims, in the corner in very tiny print is: 622x14

Indicates a 14mm wide rim.
2wheeldeal
09-24-09, 07:43 PM
I'll have to stop by a ruler shop. If I check the label on my Sun CR-18's, which are probably the same size as his wife's Matrixes, there is no dimension, and you rarely find the ISO numbers in listings from on line dealers, whereas they always list the same for tires.