The frame skeleton is the angle and dimensions of the frame (body).
It will be the basis when fitting the bicycle to the body. Parts can be adjusted to some extent, but recently
The number of ahead stems has increased, and the dimensions have become more important than the previous type of handlebar stem that can be easily raised.
Here, I would like to write about the part that the end pays particular attention to when fitting it to the body.
frame size
It is the length of the seat tube (vertical tube). Before the sloping frame came out, I decided the main size here. The length was determined by the ratio of the inseam, but with the introduction of the sloping frame, the measurement itself has become less meaningful. Depending on the manufacturer, the length of the horizontal top tube may appear.
top tube
It's sloping and now it's important here.
Another method is to determine the frame size naturally by determining the dimensions here (top tube) based on the length of the torso and arms. The dimensions vary depending on the manufacturer, but it is necessary to look closely because there is a relationship with the seat angle.
Some people say that LOOK has a large frame because the top tube display is long, but the seat angle is flat, so the apparent size is large, but it is actually a standard size. This is the part you want to be careful not to make a mistake. I think this is why I sometimes see him riding a LOOK frame that is smaller than his body.
Conversely, there are models with a long top even though the seat angle is upright. This type of model is really big, so it can be said that it is not suitable for people other than those with very long arms or those who ride in the front. Also, as a minus point, the head tube is short and the handlebar position cannot be adjusted.
seat angle
The Japanese have a large amount of retreat (pull back). If you match it with the seat angle, it will be easier to adjust the saddle position if you are lying down. It's easy to make a mistake, so it's easy to mistakenly think that it's a big frame just by looking at the top tube, but sometimes that's not the case when you look at the seat angle. Although it overlaps with the above, for example, LOOK has a long top tube because the seat is lying down at 72 degrees, but if you convert the angle to about 74 degrees, it is not much different from a normal frame. Conversely, a frame with a steep seat angle should have a short top, but if it is long, you need to be careful. Recently, the number of seatposts that can be retracted later has increased, so I think it's a good thing.
head tube length
The length (lower part of the handle) can reduce the spacer under the stem, so it looks neater and has higher rigidity. It is necessary to set the frame where this is low so that the handle position is not unreasonable.
Recently (2005 model) it tends to be longer and seems to be about 15mm higher than before. Scott, the time was already high, but I think it will be the mainstream size from now on.
Other bicycle design parts
BB has fallen, and there are many manufacturers that are not displayed recently, but it seems that the manufacturers that are displayed tend to be lower. The whole thing feels like a step back in time. Some manufacturers display the height from the ground, but it is completely different if the tire is changed, so it is not helpful.
chain stay
Varies by manufacturer. It is also related to BB decline. The long one is excellent for straight running stability and speed maintenance. If it is short, acceleration feels good. Many of the bicycles that professionals actually ride are a little longer.
front center
It has to do with handling and straightness. Short makes it agile, but it also has something to do with the forks.
offset
It's the bend of the fork. Recent forks have more carbon, so around 45 is the mainstream.
Recently, there are many things where the display around the front is omitted.
head angle
It has to do with handling agility. It feels quick when you stand up.
The handle area is determined by the balance of the front center, offset, head angle, and fork material, and it is also the part where the manufacturer's characteristics come out.