Compact bikes

[Large]

Just a question to satisfy my curiosity

I have seen some road bikes called "compact" but, to my untrained eye, look no different from any othe road bike.

Am I being a bit dim in assuming they're smaller, or is there a more technical explanation?

 

[Andrew_P]

Just a question to satisfy my curiosity

I have seen some road bikes called "compact" but, to my untrained eye, look no different from any othe road bike.

Am I being a bit dim in assuming they're smaller, or is there a more technical explanation?

Compact refers to the gearing of the fron cogs, 50 teeth big front and 34t Small front. Std is 53-39. Makes for wider gearing on a road bike for hills etc.

 

[musa]

Ahh thanks now I know difference more clearer myself.

 

[black'n'yellow]

'compact' can also refer to frame design, typically with a sloping top tube. Giant first pioneered it about 10+ years ago although it's pretty common across all bikes now..

 

[I like Skol]

'compact' can also refer to frame design, typically with a sloping top tube. Giant first pioneered it about 10+ years ago although it's pretty common across all bikes now..

^^^^^ This. A compact bike and a compact chainset are two seperate concepts. A compact bike will have a shorter seat tube but a longer seatpost to compensate. I think the theory behind it is that the compact frame is lighter and stiffer but I could be wrong on this. The other side effects/benefits are that it improves standover height so no more accidently crushed danglies and aesthetically IMO looks better as long as it is not overdone (a tiny frame with miles of seatpost sticking out just looks wrong).

 

[ianrauk]

From Sheldon..

Compact FrameTraditional "road" frames have been built with level top tubes since the early 1900s. The influence of mountain and BMX bike design has led to the increasing popularity of frames with sloping top tubes, higher at the front.
"Compact" road frames have sloping top tubes, and are intended to be used with a long seatpost. Compact frames are a little bit lighter than traditional ones, but this is partially offset by the weight of the longer seatppost. Some riders believe these frames are stiffer.
When the down tube and seat tube intersect directly above the front axle, as is usual with a road frame, weight loading only tensions the down tube and compresses the top tube. When the intersection is farther back than the axle, the bending loads on these tubes require the front end of the frame to be of stronger construction.
Manufacturers like compact frames because they are more versatile in terms of fit. Usually 3 or 4 sizes are enough to fit 98% of customers. This saves a lot of money for a manufacturer who doesn't need to deal with so many different sizes.

 

[musa]

Ahh thanks now I know difference more clearer myself.

Edit: NOW I know the difference

 

[Large]

Thanks, everyone. It now makes sense.

 

[Garz]

From Sheldon..
Manufacturers like compact frames because they are more versatile in terms of fit. Usually 3 or 4 sizes are enough to fit 98% of customers. This saves a lot of money for a manufacturer who doesn't need to deal with so many different sizes.

Apart from the 'stiffer' mention, I think the chief reason would be this one as large outfits like Giant can shave a ton of costs.