Question about bike geometry?

[deskrider]

Sorry for the ignorant question, but how do I tell from reading specs what kind of geometry a bike has? How does a relaxed geometry differ from aggressive geometry? I see the measurements and such, but I don't know what constitutes relaxed vs. aggressive. I also noticed that I got a men's bike and the top tube and wheelbase are longer than the comparable women's model, yet they still had to work with the bike because I'm short but the top tube was still a little short for me. That makes it sound like I need a long top tube despite being short (5'3") and all the womens bikes seem to have a shorter top tube.

Thanks.

[Seajay]

You have a pretty good handle on it. Relaxed/Aggressive/"Criterium" geometry is kinda bike shop jargon and it's meaning is a bit dependent on the topic and the rider.
For the most part, I recommend not worrying about it and decide if the bike FEELS good to you when you ride it.
My supposed ROAD race geometry bike was the best criterium racer I ever owned. Wide and fast thru the turns rather than sharp and slow.
These days Relaxed generally means a taller head tube so the drop from the saddle to the handlebars is LESS extreme. (ie Spec Ruby vs Amira)
It can also mean shorter (aggr) or longer (relaxed) wheelbase for responsiveness
Steeper (agg) or shallower (relx) head and seat tube angle for agility and responsiveness.

[Beane]

I have also been wondering about head tube and seat tube angles and what they mean. When you say steeper = more aggressive, does that mean higher numbers? And then slacker = more relaxed = lower numbers?

[oz rider]

The genuine WSD models will have shorter top tubes because women on average have shorter torsos relative to men. So it's about proportions rather than height. For example a friend of mine who is the same height has short legs so her critical issue is standover height, whereas I have short reach and therefore (effective) top tube is a key number for me. If you have a longer torso and fit unisex bikes, great. You'll have a wider choice of models. Just so long as it fits and feels right, cool. And both geometry and frame material (as well as components) will affect how they feel.

And yes, steeper seat tubes means higher numbers. Most women's production bikes are 75ish, not necessarily for fit but for production economics while a tri bike can be 76-78.

[zoom-zoom]

Yep, in hindsight I wish I'd gone with a men's frame, since I have stubby legs and longish torso, but I like the smaller-reach Shimano shifters on my WSD bike. My next bike will be men's/unisex and have SRAM with adjustable-reach shifters, so it won't be an issue.

[Seajay]

ZZ.. We have frequently been ADDING stem length to "WSD" bikes to get them to set up properly. Maybe an option for you to get the smaller bike you need AND add a bit of "cockpit" length?

One thing to keep an eye out for with top tube length is that a manufacturer can "cheat" their way to a short top tube on the specs page by making the seat tube angle steeper. This is ineffective b/c we just end up needing to slide the saddle back to get you over the pedals correctly....Negating the shorter tube.

[ridebikeme]

The other thing that happens in creating WDS frames is companies lengthen the headtube, which also shortens the top tube length. In reality, perhaps a bit better, simply because it leaves the seat tube in a better position.

Although you can always add a longer stem to a bike to give you more room in the cockpit; it at at times can seriously affect the handling of the bike as well. Of course, it's different from one person to the next, but I would seriously THINK about this and talk with the PROS before doing too much of this. Ideally, the bike should fit you as well as it can BEFORE you start making changes to it... in that regard perhaps another brand would fit better and even better yet Luna could definitely make that happen.