Check Out the Basic Bike Geometry

There are some basics to bike frames and bikethe length of the rider's leg, but since the compact
geometry, which no matter what, we would be wiseframe was designed for giant bikes, this has no more
enough not to play around with. Certain dimensions thatbeen the case. The length of the top tube is more
we just cant mess around with, because the slightestimportant to the fit of the rider, as we use a longer
of variations can cause and affect the handling of theseat pin to make sure that the saddle is at the correct
bike in unimaginable ways. Changes can make for aheight.
dangerous bike that may not be able to cornerWith a slopping top tube we need to draw a horizontal
properly, or descend safely, or may make for a bikestraight line from the head tube, towards the top of the
which is so close at the front-end that we might endseat tube, or actually where the top tube would be.
up catching our foot in the front wheel.Bike geometry is a complex subject, and cannot so
It would only be safer and wiser to stick with the basiceasily be played around with.
bike frame rules, while playing around with designs.Bike Frames & Seat Angles
Different frame manufacturers have different ideas asThe smaller the size of the frame, the steeper the
to what bike geometries should be applied, but certainangle of the seat tube is likely to be. Small frames
dimensions even they don't mess around with as such.work well for short riders with shorter thighs, so they
Never Mess Around - Basic Frame Size & Bikecan sit further forwards for some comfortable
Geometrypedaling. Tall riders need a much laid by angle, since
We would better keep in mind never to mess aroundtheir thighs are longer.
with the length of the chain stays, or the distanceA relaxed angle is bound to give you a more
between the back wheel axle and the bottom bracketcomfortable ride, but the most important thing is that
axle. The other is the distance between the bottomthe rider's knee has to be over the pedal, or else we
bracket, and the front wheel. The chain stays of thewill not be able to get the correct leverage, and this is
bike must be fixed around the (F) 42cm.exactly what regulates the seat angles.
The total wheel base for a normal road bike with 700cThis is the science involved in frame building; the frame
wheels must be around (G) 100 cm and which canshould fit the rider, and within reason, must stay within
vary between 98 cm to 104 cm depending upon thethese parameters so that the frame may perform
overall frame size. This length may however beperfectly. However any change must keep in mind that
changed, keeping in mind the kind of changes theycornering, climbing, descending and other performances
might bring upon.expected of the bicycle frame and geometry do not
Bike Framesget disturbed, or go hay-wire.
Earlier the length of the seat tube used to depend on