I think it's geometry?

[Kano]

There are 2 aspects to bike geometry that you might be confusing a bit.

I don't mind being confused a bit, Deb! I know I can start unraveling my confusion with the help of you and the other ladies here at TE!

When framebuilders (and other geeks) talk about geometry, they are interested in things like seat tube angle, head tube angle, length of top tube, bottom bracket drop, wheelbase, trail, fork rake. These things determine how the bike will handle, how quickly it will corner, how stably it will ride, how much flex the frame will have. They are independent of the rider. You did notice that some forks stick out more than others. That is a function of head tube angle and fork rake.

From what you've written here, it sounds like I may not need to understand the structural part of this geometry stuff quite as well at this point -- like I'll feel this more than see it, yes?

Terms -- I think most of these I've heard/read, know what they mean, but "trail"???? What's that?

Handling -- cornering -- you mean I can take corners without slowing to a snail's pace and without using the entire road on some bikes? Flex? This would be how it takes bumps?

The other aspect of geometry you were noticing (though it's not frame geometry) is how the components position the rider in relation to the bike. But some things that catch your eye are not particularly significant to the fit and feel of the bike. The angle of the stem doesn't matter, only the final position of the handlebars. A long steerer tube and a flat stem could give you the same handlebar position as a short steerer and sloping stem.

So, am I understanding that perhaps a bike can be "amended" to make it work as I evolve as a rider, at least to a point? It sounds a bit like the things that would make a bike work for me as a beginner wanting a more relaxed position could be changed out so that I could have a more aggressive "stance" if I wanted it at some point? I can see where there would be limits to this, of course, but???

The slope of the top tube also doesn't matter, only the saddle position in relation to the bottom bracket.

this relates to the knee over pedal spindle thing, yes? and how does it affect comfort? At times, I find myself scooching back a bit, and leaning a bit more forward, which seems to give me more pedaling power -- now my current bike has me very upright, since it's a "comfort bike" so I can't say my forward lean is necessarily very far: there's no drops to get into, and the bars are shaped to sit me almost totally upright.

A sloped seat tube provides more stand-over clearances and supposedly produces a slightly stiffer frame, but it doesn't affect the important frame angles and ride quality. When you are comparing different bikes, go the the frame specifications page and look at the relative lengths of the top tubes and seat tubes (use the virtual numbers that are based on a level top tube).

How can it make more stiffness? I understand the clearance issue -- oy do I understand clearance! (learned that young, and boy, you don't forget, do you?) Comparing numbers --- oh, boy, that's going to be a challenge!

Otherwise it's easy for your eye to fool you as you try to compare frames with sloping tubes. Those sloping tubes do make it easier for some people to get a good fit in a bike, so they can be an important consideration. It's just that you can't make comparisons between bikes on that basis. Hope this made sense.

Yup, Deb, it makes lots of sense -- at least as far as what I've learned at this point! I'm going to keep studying, and will also keep asking questions. I sure do appreciate the time you take with us newbies!

When I get there (the bike shop) I'm REALLY going to appreciate all the help you (and others) have been!

Karen in Boise