Bike "fit" and spinning question
 

I've got an extra large frame (25") Cannondale T800 that I love for touring. I'm 6'4" tall, and the bike was fitted for me at the LBS. BUT I find it difficult on hills to just drop down some gears and "spin" up the grade. I attack the hills instead, out of my seat most of the way. It seems when I sit down, I lose all my strength and can't keep plowing up the hill. If I drop back several gears, perhaps long enough to catch my breath/legs, I'm soon back up out of the seat again. I just can't seem to spin, which I'd like to do when climbing with a loaded bike.
I recently read about custom bike frames and other tall riders. Their frame sizes seem larger than the Cannondale extra large. Is it likely that my problem taking hills sitting down arises because I don't fit my bike properly? I certainly FEEL like I fit the bike, but maybe not? rcd

Spinning round circles takes pratice and a bike that fits properly. You need to learn to feel the spin for yourself - a shop can only recommend a starting point. It takes some time but if you work at it on level ground, in a low gear, you should be able to feel the spin. Hardest part seems to be getting your legs back over the top on the back side of the circle. You may have to adjust the saddle position either fore or aft to let you get a round spin going. Sounds kind of funny but pedaling with your eyes closed can really help - works best on a trainer for obvious reasons. Once you get your saddle position set to allow a smooth circular spin while on the flat, pratice and the position will start to translate on the climbs.

Hope this helps.

There is a sort of gumbo in your question:

- How do I know if I fit my frame"

http://www.competitivecyclist.com/

run the French fit program and see if you are close.

- How can I spin on hills?

Do you spin on flats now, is it just hills with a loaded bike that you can't spin up?

Are you locked in a death grip, by whatever technology, to your pedals? You can only pull in a circle if your footing allows it.

What you are describing sounds exactly like you are just geared too high. For a normal all around fit person, who has basic cycling technique, the easiest way to go up hills is spinning. I think I spin all the time, but when I hit a long hill I really notice the extra power I get from ankling up the hill. It is a mater of survival, I'm just not fit enough to do it any other way.

When you need to get out of the seat, it is normally you need more power. If you need more power it is because you aren't geared low enough. I do find, though, that I just can't pedal "backwards" enough to get up a hill. Even in the seat I have to draw the line and fight at some point or I will just keep loosing momentum. That is why I am spinning so hard. I am reaching out to muscles I don't normally need to just cruise along. Or at least they are muscles I get sloppy enough not to always recruit.