Road Bike Frame: What Is The Difference Between a Compact and a ‘Traditional’?
|August 18, 2010||Posted by Andrew Gray under Bike Tech|
If you want to rock your bike up hills, then you can either go for a small frame, or get one that fits and go for a compact. But what is the difference between compact and traditional frames?
Round where I live there are couple of blasts from the past. The Raleigh Banana. Apart from the fact that I can’t spell Banana very well (dyslexia) this awesome machine was the first road bike frame that I owned that could be described as being built based on racing geometry. The banana bike has been seen lurking in the possession of an early 20 year old, so I must assume that it has been inherited. I saw another one in a somewhat shabby state in Oxford the other day. And it doesn’t surprise me. These composite steel frame road bike were wonderful, and I spent many days rocking it up hills, and only snapping the back axel twice. But not one crack in the frame.
This was the traditional model, with a horizontal top tube. The difference today is that, whether it is fashion or some other point (below), horizontal top tube machines could be on the way out. The compact sloping top tube is on the way in. And I will come back to my own personal opinion as to why I think this is a good thing. Let’s have a look at the opinions of others first though.
If it’s good enough for Lance Armstrong, then it’s good enough for us. Lance is pretty good on a bike, and knows his way around the beast as good as anyone, and he has shifted over to the sloping top tube compact. But perhaps it isn’t Lance’s influence that has moved it in this direction.
It certainly hasn’t escaped this noob’s attention that there is an uncanny resemblance between a mountain bike sloping tube and the compact road bike frames. Mountain bikers would perhaps say that it is to protect certain areas of the anatomy from unfortunate sudden stops. Others would say it enables them more space to perform awkward manoeuvres. I tend to agree with both these sentiments. But was it worth moving them to the road bike?
The main point here is that for some reason which escapes me (make a comment if you know!) the manufacture of a sloping top tube means that the manufacturer need supply fewer options of road bike frame size. This means less production cost, which I guess in theory means either passing the savings onto the customer in terms of cheaper bikes, or else giving higher spec components. Whether this will or has happened is a bit of a mystery with such a volatile international market place.
The manufacturers would like to argue that the weight of a compact frame is less, though when you get to the top of the range carbon road bike frame options I think the difference would be negligible. Besides which, you might be adding the ounces back on with the necessary longer seat pin.
Ok, so what about my opinion?
Well the first is to do with sizing. Bike Cycling Reviews has published a great article on making sure that you size correctly, because you can’t use the usual stand-over method to size your bike since depending on where you stand will make a difference! Instead, roughly speaking, draw an imaginary line from saddle to bars, and this becomes the top tube height. I suggest reading the article for more information. Because there are fewer road bike frame options new buyers are less likely to make a mistake with their frame sizing choice.
The second however goes back to my days on the Banana. Now I know that a lot of people will say it is bad form, but when I am going up a hill I do like to rock that frame as much as I can, and when I bought the Raleigh I bought a small frame so that I could do just that. The compact really comes to the rescue for me here, because I can get a proper fitting frame but without compromising on the size issue. You see, I need the room to rock the bike over and have the frame top tube somewhere around my mid thigh or lower. This allows me to put the kind of power down I want to without risking a hernia.
So what is a good example? Looking around I personally think that the Scott Speedster S30 is a good start up bike. My local shop recommended it to me since the components are good quality, and the frame a bit cheaper. When it comes to upgrade, I can get the next frame up which comes with cheaper components and then just switch about to have a cheap and cheerful training bike, and a nice full spec for race days.
And if you don’t want to rock your bike, though I have no idea why you wouldn’t, then why don’t you just settle for an exercise bike and just play it safe…?