Originally Posted by
Carbonfiberboy
There is a difference, however. A light bike "gets out of the way" of a strong pedal stroke. It accelerates as the pedal force peaks, so that the peak force duration is relatively short. A very heavy bike, however, does not accelerate away from the pedal at the same cadence, so the high force duration lasts longer.
If you shift up a gear or two on your lighter bike it would feel much closer to the heavier bike.
When I first started tandeming, my legs hurt like the very devil after 30 miles, and I was accustomed to riding doubles and 400s in the mountains on my carbon single. The hills also last a lot longer and the descents are shorter. My tandem cadence is usually the same as my single cadence, BTW, so it's not that.
You were likely just putting out more power and working harder on the tandem. It's somewhat like riding in a group. It's natural to ride a little harder and put out more power when you're on the front pulling.
It would be interesting for a younger person to experiment with this. Do hilly group rides on a 100 lb. bike, backing off your competitors one level.
I have a couple of champion ultra racer friends who, in their younger days, would come out to the group rides pulling a large dog in a kiddie trailer. They would still drop us on the hills, and we weren't that slow, most of us finishing RAMROD in the first 100. It was pretty funny, average duffers compared to the real deal. I don't know if they got anything out of that other than being able to ride with us and still have fun.
Using a heavier bike in a group with slower riders would allow you to get a better workout than a light bike. Or just put on some fenders and wear baggy clothes.