I bought a Trek Lexa SL at the end of last year and like it so far, but I'm pretty sensitive to road vibration. I've switched the saddle, wear cycling shorts and gloves, but I still feel it quite a bit. Now my riding distance is expanding and I'm finding riding on well-maintained crushed limestone (gravel) trails is going to be unavoidable at least part of the time. Also, I live in Wisconsin, which means we have some crappy roads due to freeze/thaw as well as sealcoat often used on roads for patching (though my concern is mostly with trails). Anyhow, I'm thinking of replacing my 700c x 23 tires with either 25's or 28's. I want more comfort and better handling on those trails (admittedly I haven't ridden the trails on my 23's much), but I also started to do triathlons and road races and am beginning to be somewhat competitive so I'm worried about how much speed/efficiency I'll sacrifice. Finally, I'm quite petite - 5'1" and 105 lbs, and I have an impossible time pumping my current tires up to 110 psi using my floor pump - I have to have my husband do it for me (not very practical). Any advice on 25's vs. 28's? Also, should I look at any tires specifically or just pick up the Bontragers at the Trek store? Would it be a stupid hassle to switch out 28's for training and 23's for events? Thanks for any advice!