foomonkey

Pardon my ignorance, I'm relatively new to road biking and I'm trying to learn. I don't even own a road bike yet!

I have been looking around at road bikes and I've seen many available as "Compact." What does this mean and why would someone want one? I presume it means a smaller frame.

I am curious because I want to make sure I get the right bike for my body size. I am 6'1" and I've been told that a 56cm would probably be right for me.

Thanks and sorry for such a "newbie" question.

Andrew

indygreg

quick answer is that it has a sloping top tube (as in it slopes down from the head tube to the seat tube). A traditional frame has a level top tube.

Size wise, you are not on a smaller frame - a 56 is largely a 56. They measure the virtual top tube.

Advantages (this is from the seller's perspective, not saying they are true)
Less material
Stiffer due to the above

The variable is looks. People newer to road cycling, especially those who come from MTB) seem to like compact geo better.

DXchulo

Compact frame:



Traditional frame:



Compact frames have a sloping top tube. There are a lot of arguments about the benefits of both, but I wouldn't let it be your #1 deciding factor if you're buying your first bike.

SBSpartan

Nice post.

A lot of people here say you need this for this and that for that. I am a big fan of, you need what works for you. Ride a lot of both kinds of bikes and get the one that feels the best. Ultimately we are talking about fit.

One thing that hasn't been said is that a compact tube will keep you closer to the handlebars and the traditional will spread you out more.

mihlbach

What??? A sloping versus flat top tube is basically irrelevant to fit, given two frames that the other tube lengths and angles are the same. The only difference is that one has a sloping top tube...to compensate for this the seat post is longer. There is no other difference. Given a properly fitting frame, the spatial relationship of the seat, bars and bottom bracket should be the same.

indygreg

the fit should be the same, it is just using more seatpost (as said above). I do think that a compact could be stiffer all things equal.

MichaelW

Beware that "compact" also refers to chainsets.

Compact chainsets have a smaller diameter bolt circle (110mm Bolt Circle Diameter vs 130mm for std Shimano and 135mm for std Campagnolo).
The main difference is that smaller bolt circles permit smaller chainring rings and lower gear ratios which is often a Good Thing.

foomonkey

Thanks for the info. Looking at the Scott catalog here, I see that most of the high-end models say, "Compact Version Available." I am assuming that means the sloping top tub.

Hope I didn't start any flame wars with the question!

Look for more ignorant newbie questions from me soon!

Andrew

big john

You'll notice that some manufacturers make compact style frames in just a few sizes, such as small, medium, large, etc. Traditional style frames are sized by metric seat tube length,(usually). As has been said, ride different bikes and see what fits you. I'm 6'2" and I ride 62-64 cm frames.

indygreg

If there is a 'compact version available' I would think that means the crankset. To the best of my knowledge, no one is making a traditional and compact version of the same frame.

As someone else pointed out, compact cranks have 2 rings that are smaller than the traditional full size crank. This allows for lower gearing out of a double, something many find very nice.

daytonian

Huh??

StanSeven

If you do a search here, you'll find quite a bit of information (as well as mis-information). A few years ago, a couple manufacturers tried to get away from producing so many different sizes and substituted fewer sizes (small, medium, large, extra large, etc.) while offering a variety of stem lenghts and seatpots to allow dealers to make finer sizing adjustments. Giant was probably the largest. Some people called this "compact" geometry, which it really isn't.

Also some manufacturers started using sloping top tubes as well. However this isn't "compact" either.

However when you combine a sloping top tube with a smaller rear triangle, you get something a little different in terms of ride characteristics and maybe a little less weight savings. The weight difference is marginal at best, because you usually need a longer seatpost to work with the shorter seat tube.

The resulting benefits include a potentially stiffer rear on the frame than can help with out of saddle climbing and sprinting. As I mentioned, some small weight savings can occur.

For most people, the sloping top tube adds to comfort is dismounting and being able to stand at a stop sign/light easier. The older falt top tube look is favored by many "traditionalists" but it's hard to find frames without the sloping tube. I noticed that all but four Tour de France team bikes this past yaer had sloping top tubes.

msheron

A frame you fold up in a nice little package......just kidding. I believe it has been answered here.

clausen

The only thing a compact frame has over a traditional frame is that it gives you more stand over height.

grahny

i've got one of each and they both go in a forward direction as long as my legs are still moving. Although I can fit the compact frame in a smaller carry on bag when traveling... 'cause it's compact? sure.

FrankBattle 

+1

My compact's a 58.5 cam and the traditionals are 61. *shrug* a bike's a bike's a bike, at least in my stable.