[python] Re: New Python - 20" or 26"?

Jaime Cristovao wrote:
Hello again Thank you for your comments. Very helpfull. 
Dirk, you are right, I was thinking on 5 mts full turn, 2,5 mts radius... my 
mistake and my bad english. :). Anyway, very good news for me.
Like I said, I am not sure a 26" will be able to do 5meters, but it will be about that. Somebody with more experience with 26" might be able to say definitely. 20" has no problem with that - I can U-turn on the smallest of roads.
Jürgen, my inseam height is about 84 cm, wich I suppose will be enough to a 26" front... well, at least it works for a thinner, low profile tire (1"95), bus I want to use a "fat" one (2"0 low pressure).
You could use a slightly smaller cranks (160mm or below). I have a simular inseam and I find shorter cranks fit my legs better then those 170mm cranks. That way you get more reserve to put whatever tire in you would want.
The measures I've been taking yesterday were not conclusive; I'm afraid I will have to raise the BB about 2"or so to use a 26" front - Is it possible without compromising the overall performance (stability)? I suppose there must be some kind of relationship between the horizontal distance between the pivot, contact path and BB. 
Not from the viewpoint of stability.

There are other factors, which are explained in:
* http://en.openbike.org/wiki/BB-Seat_Diff. (last point is included in link!) 
* http://en.openbike.org/wiki/BB-FWA
For stability, my personal recommendations: wheel base: long, and pivot angle: 60+degrees, and neg. trail (as little as possible, minimum is defined by the wheel size). 
I just don't want to use a 24" front because in Portugal there are very few 
tire types to choose to this size.
One question: how faster a python can be? (average and top speed).
On my own python I went up to 66kms up to now - my max speed is due of lack of chances to try higher (I live in Danmark). It does take time to get use to these speeds, but then it doesn't feel problematic.
Serge on his "birdcage", who is at a beginner level, went 57kms on 26", and said to me he easily could go faster. "it felt really stable".
I am a pro-handlebar python rider, and I think if you want to go really fast downhill, then you should put handlebars on: Last time (Öresund rundt in Sweden), at a particular hill I wanted to see how fast I would go without touching the handlebars, and my limit was at a little over 50kmh: then I had the urge to put my hands on the handlebars.
And did anyone found any relation between the total weight (bike+rider) and the maximum speed? 
The fatter, the faster? :-)

dirk

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