Quote Originally Posted by SadieKate
Why don't you try an experiment? I assume you feel the hybrid is slow even when you aren't towing the kids? So, just swap the tires and put the 700x25s on the hybrid. 35s will probably run slower but it depends on tread and pressure. 35s just weigh more also and it's rotating weight.

You could be talking a lot of money to make wheel swap work since the entire drivetrain is probably waaaaay different. You may just want to invest in narrower faster rolling tires for the hybrid. I suspect the old roadie doesn have indexed shifting?

Why not just ride the roadie when you want to go fast and ride the hybrid when towing the kids.
yes, I've thought of just swapping the tires, but I don't think I can put 25s on the hybrid rims. I don't know exactly what width rims these are (they're matrix 750s, haven't found specs anywhere). According to Sheldon Brown's site, I can probably put 28s on. But I don't know that I'd be happy with skinnier tires when I'm towing the kids, that's why I thought about using the second set of wheels. The hybrid (as it is) is perfect for the family outings and since it's alu it'll be great in bad weather (I'm also getting fenders).

When I ordered the hybrid, I hadn't ridden the road bike in about 15 years, and felt really unstable on it, b/c of the tires, the drop bars, and the downtube shifters. Plus, I had a horrible time on even the tiny hills near our house. But in the 5 weeks it took LBS to get the hybrid, I've become much more comfy with the tires, responsive steering, and even the body position, but still am not crazy about the downtube shifters and narrow gearing. Although, I am certainly improving on the hills! So I'm not totally satisfied with that ride either.

In a perfect world, I'd just buy a new road bike, but can't really justify that expense now. So I thought about upgrading the road bike, or then I wondered if just decreasing the rolling resistance on the hybrid would be satisfying enough. It seemed like getting a 2nd wheelset for the hybrid would be a cheaper option (especially if I could use my roadie's wheels or buy a used bike to scavenge the wheels) than upgrading the roadies crankset , FD, shifters, etc., not to mention brakes from the other thread!) and would be a fun project if I knew that reducing from 35 knobby tires to 25 smooths would give a serious increase in performance. With quick release, it just wouldn't be that big a deal to switch wheels in addition to hooking up the trail-a-bike for those family outtings. And, if that was a good ride, I wouldn't neccessarily ever put the wheels back on the roadie so I wouldn't have to worry about backwards compatibility. But keeping the roadie intact would be one advantage of trying to snag some cheap 700c rims from a garage sale

Thanks for your input.