I'm thinking of flying over to America from UK next year some time with my lass and spending 2-3 weeks riding around Yellowstone national park and the Canadian Rockies. Do any of you have any tips on routes to take, best time of year to go, places to see, good hire bike companies etc? I've done a little bit of touring around the Pyrenees and Alpine mountains in Europe. I normally try and stick to 250-300 miles a day.

Have you checked out ADV rider? Pretty sure it'll have been covered many times over with lots of info and advice.

Been to Yellowstone at least once every 10 years since the 60's. One of my favorite places in the US. The thing you have to sort out is the crowds of people. Get up early to site see the large draw places. If you see a tour bus show up, leave and come back. Most tour bus people are city folk with zero personal space and will run you over. Bike travel is a good thing to get around traffic jams. Some people have never seen a deer and will stop dead in the road if they see one. Just drive around them. It's higher elevation than a lot of the US and I have used heated gear in the summer, during a rain shower. Bear Tooth Pass is a fun road at the north end of the park. 75mph posted speed limit.
Big Adventure bikes are a good bike to use out here. There are gravel road to get away from the average cage driver. Last time there I was on a Triumph Tiger ADV and made use of it with some gravel / dirt roads. I bike camp as much as possible, so I can stop just about anywhere to pitch a tent. Harder to find a motel, especially in peak seasons at the large parks.

Follow the Rocky Mountains north into Canada and you can't go wrong....except for the tourist traps like Banff. Love the place but the people......arggg but hey...I am a stick who lives in Oregon.....
I 'd rent me a new KaToom ADV 11XX if I had deep pockets...

All good contributions, but before spending an infinite amount of time (and one can ...) trying to mine ADV:

- When were you planning to do this - approximately? If you are seeking advice, I would suggest after "labour Day", but not too far in to September, as it can snow (substantially) in these areas by then. In summer (being more or less defined in the US as the period between Memorial Day and labour Day), the national parks and areas - as you may imagine - are inundated with tourists. The later in the season (closer to labour Day), the worse it is. Early June is probably less than ideal as well, as it can still be fairly cool (snow on ground/can snow) in these areas.

- Going it alone, or do you have a group?

- How would you prefer to overnight? Lodges, hotels/motels, or tent/camping? It matters, in that some bikes are more well suited to stowing. carrying, and unpacking gear needed for camping. There's the matter of said camping gear, and bringing all that across may not be practical ...

- Have you considered signing up for a guided tour - all inclusive kind of thing? I know that this suggestion may not seem part of the SDer ethos, but some of these programs are not only impressively well organized, but allow ample freedom, and are generally very civilized in accommodation arrangement, no matter how "rustic". This allows one to focus more on the ride and their holiday, than the logistics.

- What kind of bike do you prefer? If you have zero plans to head off road at all, there's no need for a DS/Adventure bike. Who knows - maybe you prefer touring on a cruiser - ? I ask, in that we can then point you to some resources for rentals. Of note, starting in Colorado may be your best bet for this - probably the most offerings and greatest variety of bike rentals, tour services, etc. outside California. In Canada, everything is likely to cost more.

Give us some specifics on what your ideal arrangements might be, and I'm sure many here will be able contribute.