Tire Size

[kfergos]

I need some tire size advice.

For my summer bike I have 700 x 28C tires, which have served me quite well over last summer when I just commuted. This summer, I'm also using that bike to train for the Cape Cod Getaway and the STP, a couple of two-day-long rides that are 75 miles and 100 miles each day, respectively. That means I'm already spending a lot of time in the saddle on top of my normal commute, and I'm debating about getting narrower tires to speed things up a bit.

Should I look at getting 25s or even 23s (I think even those would fit with my wheels, but I'm not sure)? What might be the commuting-related issues with narrower tires? Do they get flats at any different rate, or anything? Should I consider getting puncture-resistant ones while I'm at it (I expect to be moving to Seattle within the next year, which seems to have tons of glass on the roads, so puncture-resistant might be good...)?

I already have an abundance of mountain bike-sized tires floating around my small apartment, and I don't really want to add a pair of 28s to the stack if I did go with something narrower. If I did switch to something skinnier, do you guys know about doing just a straight swap of used tires anywhere?

Help!

[bean fidhleir]

I think your rim width completely determines the narrowest tire you can safely use. You shouldn't try to use a tire that's narrower than the rim.

I don't think the width as such has much effect on flats, etc, though I suspect the narrower the tire the more likely you are to have one that has thin rubber which of course would affect flats.

[uforgot]

Sheldon Brown has a chart of rim widths and tire sizes that fit those widths. Scroll down the page to the center and the chart is bright red and green. You can go to your rim's manufacturer's website to find the width of your rims. I've been looking into new wheels this past week, so I've been researching it a lot!