VOTE: S&M Intrikat TT Height

[Ultraman Zoffy]

I don't necessarily agree with your definition of it, but what you said at the end is dead on. Which is why a new term NEEDS to be developed, by us....for us.

We'd probably need to call it something lame like "jumpover height" for it to make sense in flatland.   

[wookie]

I agree that the terminology and the actual vs effective measurements could use some refinement. 
Seattube length alone does not always give you an accurate idea of jumpover/stepover height.  What if the bb is really high or low?  what about the curved/angular gussetted top tube designs? 

The measurement that most of us are really looking to compare is the height of the top of the toptube from the axle level about 40% of the way between the headtube and seattube.  We could assign it some arbitrary name or coordinate and request it from the retailers on current frames and try to establish it as a standard for future products?  The headsets are all the same now so the stack height isn't and issue but not all forks are exactly the same length (a standard would need to be established there as well).  Obviously the rear dropout slots would also need to be perfectly horizontal with this fork standard to get an exact reading.

[stuntnuts]

Given the axle line, the bottom bracket height and the seat tube angle (all commonly given specs), the seat tube length dimension would give you a good idea of how your "step over height" would feel.

[pwh4130]

Measuring the distance from the peg to the center of Top tube is too variable.  TT length will throw it off for one and don't get me started on "tailwhip height".  

Using the industry standard definition of standover height, it should give any experienced rider an understanding of how it will feel.  Things such as tire size, peg size, fork offset and axle to crown length will all change the peg to TT measurement from a riding application.

Measure the bike you like.  Write down those numbers and compare them when you shop for your next frame.  It's that easy.  I know Sheldon Brown has nothing to do with flatland but he knew bikes and everyone reading this can learn something here.

http://www.sheldonbrown.com/frame-sizing.html

[wookie]

Brett, I agree that there are many variables.  That's why I suggested using the center line of the axles as the starting point.  Sure bigger pegs will change that, as will headangle and toptube length, etc.  But it would give the riders out there that don't understand how/why/where of figuring out these dimensions a starting point and an easy comparison from one frame to the next.  BMX frames are by far the worst documented when it comes to "actual" geometry and that needs to be changed.

[Ultraman Zoffy]

Sure bigger pegs will change that

This was funny to think about in the midst of this whole top tube debate... imagine someone going nuts and using bigger diameter pegs to compensate for a high top tube. 

[pwh4130]

That's a good point.  When I had this frameset I had no problem stepping over the frame when standing on the pegs.