New 700c rims to replace 27x 1 1/4 wheels?
 

I have a new to me old Austrian Sears (I think Puch made) road bike that I find comfortable but don't care for the wheels. Could I get away with using 700c rims on this thing? There's some vertical adjustment that can be made on the brake pads.

It needs tires anyways (the ones on there are likely 30 years old) and the rims are too hard to true due to warping of the sides. May be a good time to upgrade. It's a $20 bike and I don't want to put a ton of cash into it (say under $100 done). I don't mind buying used as long as they're straight. Is this a doable venture (rims and tires for $80)?

Yes. If the brake pads can be adjusted 4mm down then 700C wheels will fit no problem. This will sometimes allow you to fit a tire of a couple mm wider as well.

Keep in mind that the further the pads move from the pivots on the brake calipers, the less braking force you will get from any given amount of hand force at the levers.

I didn't think of that with the braking force. Makes sense. I would think going from chromed steel to aluminum would help bring up the braking force a good bit. I notice all my aluminum wheel bikes stop a lot better than these old steel rims. The steel rims make brakes almost non existent if a little bit wet. I've learned to stay off this bike when there's any moisture on the ground.

If the wheels are decent with aluminum rims I would just get some nice tires like Panaracer Pasela's. 27 inch wheels ride real smooth since they're a larger diameter. That's why the MTB's went to larger diameter wheels. I've always thought the industry should revive them with some modern 27 inchers with wide disc rims and fat tires for gravel bikes.

The change in braking force is noticeable, but not catastrophic. The brakes are designed to work with the pads at any position in the slot, so you're still in the acceptable range. And, yes, changing from chrome steel to aluminum rims will likely make it so that the sum of all changes will result in an improvement in braking, especially in the wet.

For that matter, maybe 700A or 700B deserve another look. ;)

Your bikes with alloy rims that you say you notice a difference in the braking force might also have double pivot brakes which are also a big improvement at the time for brake technology. And such brakes are typically inexpensive so if yours aren't and you still desire better braking, you might try some double pivot rim brakes available in most all brands and flavors.

The grippiness of aluminum compared to steel .... if you have ever depended on your brakes on your steel-rimmed bike, you know how little use they are compared to Al.

I think you are dreaming with a budget of $80 for a pair of used 700c wheels including tires. I checked out our local CL which serves a population of nearly 2M. There were no wheels for sale at any price. You might do the same on Facebook marketplace but I doubt you will have any better luck. If there is a bike co-op nearby, contact them. Sometimes people donate bikes to them and they use them for parts. My local Goodwill only seem to have junk these days. Once in a while I see wheels in the bins at my local Goodwill surplus store but that is very hit and miss.

Probably so. I did look on ebay in sold listings and saw one set for $69 (tires and wheels). I also found tires for around $40-$50 a pair. Rims can be had with spokes for $60 to $100 on the cheap end. So I'm not way off, but I did think the same after I posted the original top post.

I'll probably just live with the minor annoyances of the factory rims. It's really not that bad. New tires and they'll be fine.

Yes, going to an aluminum rim will definitely help with wet weather braking performance. You might also consider replacing the brake calipers with dual-pivot calipers to improve mechanical advantage. Tektro makes an inexpensive, long-reach, dual-pivot caliper I've used for such conversions.

The trick is that you have to adjust the brakes all the way down onto the rim brakeing surface. If the brake pads touch your tire, even a little bit, you are asking for a blow out.