dougmc

2 meter repeaters generally have a channel separation of only 600 KHz -- pretty small. This generally requires a duplexer that's pretty good sized and tuned to the specific frequencies used to keep the repeater's transmitter from swamping (desensing) its receiver. This generally means that a good two meter repeater isn't small or cheap. (Though if it recorded the signal and then replayed it when it was done -- that would work fine. It's less convenient, however.)

In the 70 cm band, the usual separation is 5 MHz if I recall correctly -- that's easier to deal with. Not trivial, but easier.

Many portable radios (both hand-held and mobile (for car use)) that do both the 70 cm and 2 m bands can repeat between the two -- listen on 2 m and repeat on 70 cm or vice versa -- all this in a small, inexpensive package. But in order to use this, everybody would have to have 2m/70cm radios, which are more rare than just 2 m radios.

Of course, I'm not sure what the benefit is to having so much more power than everybody else unless you want to be "the hub" that everybody goes through. People could hear you, but you couldn't hear them.

Since this ride is a century ... 100 miles of range is a long ways. More than you're going to reliably get with any VHF gear. A good repeater with an antenna at the top of a mountain in the middle would make it work, barely -- and such repeaters are rare. More power isn't going to fix this -- line of site is the issue. I imagine you're already aware of this, of course.