Different bikes...difference in speed?

This might be a foolish exercise but I’ll ask anyway. I trained this winter with my tri bike on my trainer. I have not had my Tri bike out yet as our roads are still covered in sand and ice in spots. I did take my mountain bike out this weekend for my first outdoor ride.

I covered 50 km in 2 hrs. (I do the sport for fun and to keep fit…no threat to the podium here).

With the same effort (HR) how would this equate had I been on my tri bike. The mountain bike position is far from earo and the tires offer more resistence.

The reason I ask is that I believe I’m in better shape than normal for this time of year but have always made the first ride on road bike.

I’m thinking I would have been over 30km/hr. Any thoughts?

You must specify your tri bike. But here are some rough numbers:

Cervelo P2k : 30.475 km/hr

Cervelo P3: 31.865 km/hr

I don’t know how you could possibly get any kind of numbers here. A mountain bike has you in a different position, putting different stresses on slightly different muscles, with a significantly greater rolling resistance and less aerodynamics.

You must specify your tri bike. But here are some rough numbers:

Cervelo P2k : 30.475 km/hr

Cervelo P3: 31.865 km/hr