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Compact vs. Classic geometry - a quick tutorial needed!!!(6 posts)

Compact vs. Classic geometry - a quick tutorial needed!!!SeanKellys-reincarnate
Aug 29, 2003 12:49 PM
Hi

i am getting pretty close to purchasing a new litespeed bike

i have been fitted up by the LBS and they said the Litespeed Siena would be an ideal bike for me... (5'8" , 160 lbs.. bike will be used for mainly club rides and fitness riding.)
it is a compact frame which played into their choice ie: "oohh you would be a great canditate for a compact frame!"

however the classic tuscany felt more natural..
keep in mind that i have ridden a classic steel bike for the last 13 years and that probably played into that.

so what are the advantages/disadvantages of a compact frame.. is it better for some body types? does it take some getting used to? is there a different feel to it? is it a passing fad?

also ..why now are the break hoods so high up on the bars.. and the stem angled up.. again after riding a classic set up for so long it just felt strange.
kids these days??

any and all opinions would be greatly appreciated!!
joe
re: Compact vs. Classic geometry - a quick tutorial needed!!!laffeaux
Aug 29, 2003 2:00 PM
Compact geometry give you more stand over height for a given frame size. If you are somone with short legs, and a long torso, a compact frame will give you better clearance. Beyond that it's purely asthetics - which do you prefer? It's very unlikely that you'd be able to feel any difference bewteen two bikes that were completely identical except for the sloping top tube.

The position of the hoods on the bars and the stem have absolutely nothing to do with compact or standard geometry. Set the bar and stem however you feel comfortable - it's all personal choice.
re: Compact vs. Classic geometry - a quick tutorial needed!!!rgass
Aug 29, 2003 3:40 PM
I faced this same choice a while back, and went with a Tuscany, based on aesthetics.

In theory, a compact geometry frame would allow the bike to be lighter (shorter top tube). For Litespeed bikes, however, the weight savings is minimal. A "small" size Sienna weighs 1,394 grams, whereas a 49 cm Tuscany weighs Tuscany weighs 1,446.

It is true that standover height is not as much of an issue with a compact frame. With a traditional road frame you'll need an exact fit (top tube, stem, etc.)

I simply liked the looks of a standard frame better. The sloping top tub reminded me of a women's bike frame from the old days. I'm old school I suppose.

The Litespeed Ghisallo--which also has compact geometry--is another story. It is extremely light (only 877 grams for the "small" size. So if you prefer the compact geometry, I'd go for the Ghisallo. It is a great bike for climbing, sprinting, just about everything.

Whatever you decide, Litespeed makes GREAT bikes.

Hope this helps!
no real difference...C-40
Aug 29, 2003 3:54 PM
If you compare the Siena and Tuscany geometries in the 53& 55cm sizes (one of which is right for you), the only significant difference is the head tube length, which is 6-7mm shorter on the Siena. This will require more head tube spacers or stem angle to get the bars up to the same height. The head tube angle on the 55cm Siena is also .5 degree steeper, which would make for a bit quicker steering, unless a fork with less rake was used.

Other than that, I don't think you'll find much difference. I have both a conventional frame and a sloping top tube frame. Don't even think about it while on the bike.

If you're used to riding a bike with a quill stem, you've been raising the stem to the necessary height simply by lossening the bolt on the quill. The new threadless integrated headsets most often require a stem with some rise due to the limited ability to raise the stem on the steering tube and generally lower total head tube length (including the headset). The maximum number of steering tube spacers is only 2-3cm if you get a carbon steering tube. You'll get a stiffer setup with as little spacer as possible. Using stem angles of 80-100 degrees (rather than 73) is now the norm.

To avoid problems, measure the height from the floor to the top of your bars on your current bike and I can tell you approximately what it will take to get the bars to that height with a threadless setup. For example, mine are about 87cm above the floor. I make sure that I can achieve this height with 5mm or less of steering tube spacers, using the necessary stem angle.
My .02TNRyder
Aug 29, 2003 7:06 PM
Just recently bought a new bike myself and went through some of the same ?s. Some points and observations I have made!

A compact frame of the same size as a standard frame will be marginally (sp) stiffer due to the fact that the triangles will be smaller. This could be more noticeable with a Ti frame as the material is more flexible.

In the test rides that I have made, the compact frames seemed to handle a bit quicker than the standard frames. Purely perception, but it is the way it FELT to me. I am sure that actual frame geometry has more to with handling than compact vs. standard.

See earlier reply about stem and brake hoods. But putting the brake hoods higher up make it easier to shift and brake occasionally while riding in a paceline. I no longer need to drop a hand into the drops to brake! cool!

I am also jealous of you in that you are trying to decide between two Litespeeds;)! In the end, it really just depends on what you feel most comfortable on. If you prefer the way the bike with traditional geometry feels get that one. You are the one that will be riding it!
re: Compact vs. Classic geometry - a quick tutorial needed!!!fbg111
Aug 30, 2003 5:58 AM
http://forums.consumerreview.com/crforum?viewall@5.nhCua9VKjhX^268299@.efb23b6
http://forums.consumerreview.com/crforum?viewall@5.IDY5abErlXg^0@.efb7711
http://forums.consumerreview.com/crforum?viewall@5.iaDBa2Oil19^771704@.efb870c
http://www.cannondale.com/bikes/innovation/sloping.html

In a nutshell, compacts are stiffer, lighter, and have lower center of gravity. Of course, there is some dispute over those claims, as demonstrated by the cannondale article above. I think most experienced riders would just recommend you get the bike that feels most comfortable to *you*. As for the stem on the compact you tried, that's just the way the store set it up. You should change its configuration if it doesn't feel comfortable to you, as I did after I bought my Giant TCR2.