I know that top tube is the distance between the head and seat post; the seat tube is the distance between seat post and the bottom bracket; and the head tube length is the length of the tube below the head, but I was hoping someone could help with the following Geometric bike frame descriptions:
1. Stand over height 2. Head angle 3. Seat angle 4. Wheel Base 5. Chain Stay length 6. BB height
All these are geometric descriptions that I've seen used by most MTB and Road manufacturers except stand over height. I've only seen this used by Specialized I believe, but I may be wrong.
I currently have a 1998 SJ HT and I'm in the process of buying a new ride and my '98 fit so well that I want to get somthing similar.
1. Stand over height = top tube to ground. Too high and you crotch yourself when you straddle the bike.
2. Head angle = how far the head tube of the bike "leans" back. The higher the number, the closer the tube is to being perpendicular to the ground.
3. Seat angle = same as above, but for the seat tube.
4. Wheel Base = distance from front hub to rear hub, or the distance from where the front tire touches the ground to where the read tire touches the ground (same thing).
5. Chain Stay length = distance from center of crank to center of rear axle.
6. BB height = distance from bottom bracket to ground. Higher means more clearance for logs and things.
I dunno if anything is "deemed" a "good" bb height. I think the best thing to do is to look at some catalogs and get a feel for what a common bb height is, and tend toward the one that suits you more (i.e higher if you do a lot of log crossings).
I've developled some personal preferences when it comes to geometry. For mountain bikes, I personally prefer steeper head and seat tube angles. I just like the way they affect bike handling, plus if you put a longer fork on the bike (to increase travel, for instance) you don't have to worry as much about it slacking the angles up too much. I also prefer a shorter wheelbase, and I especially prefer short chainstays (I find they tend to make the bike climb better).
But things I like may not suit you, or your riding style. Or even the type of trails you ride on. You kinda need to ride a lot of things and see how geometry changes affect you. Fortunately for me, I'm old, so I've had a lot of time to experiment. 😉
