X'igaa Kaa

Some basic information you may need to consider:
70's Nishiki International 10-speed
Right now I have:
Rims - Sunrims CR-18
Wheels - Vittoria Zaffiro 27 - 1 1/4

I've put a little over 1000 miles on them both, and want to get some better tires, and have been leaning towards Schwalbe Marathons. which they do have in 27s, online.
Would it just make more sense to upgrade to 700s so I'd have more tire options and wouldn't have to order them online again in the future?
My thoughts are, that the rims are still just fine, and should have many more miles to go on them, so spending money on new ones just seems excessive right now. but, it might be for the best.
Right now, I'm mostly just commuting around campus and around town, putting in roughly 5-10 miles a day, but I want to tour more as well.

Thanks for your help

zephyr

When changing from 27" to 700 rims, the brake pads will need to move further down on your brake caliper arms. If you have medium or long reach side pull brakes, it might work OK. Short reach brake calipers might be a problem because the brake pads might not hit the braking surface of the 700 rim. It's not good to have the brake pad right at the top of the rim, too close to the tire. Cantilever brakes might not work at all for the conversion. I tried a 27" to 700 conversion on a Cannondale with canti, and the front brake arm was too high up on the fork for the brake pad to contact the rim in the right location.

Sun CR18 rims are great, I have 3 road bikes and nearly all the wheels are CR18. Based on the description of your bike, I would not invest in new wheels. I'd rather buy 27" mail order tires for that bike even if they cost a few bucks more. Good tires last 3500-4000 miles or more depending on use. Your wheels should be fine for some touring (assuming they are 36 spoke). Some beefier 27" tires is all that you might add.