the slope is the difference between actual seat tube length and virtual seat tube length
Ah! Got it; yes, of course! Thanks, Iain! Nice work.
It took me a moment to realize the significance of the "52" in the 565S-52 designation on the 2012 size chart...the forks now come only in 2 offsets (46mm and 52mm) to cover all frame sizes in the entire line, not the 4 offsets (43mm, 46,, 52mm and 59mm) used to cover the 2011 line. A natural consequence of dropping the smallest and largest frame offerings in the line.
Oh! Judging by the <bing!> of my email alert, it looks like you posted while I was writing the above, so I'll append to catch your latest...
would the 600 S fit you Dan?
Another good thought, Iain! Hmm. Yes...it looks closer on frame geometry in some ways but is further off in others, and uses the fork with less offset (46 vs 52), so trail will differ if the head angle remains the same. Just a sec, and I'll run the numbers...
Let's see...we don't have the head tube angle, so I am going to specify it the same as my 560S at 70.5 degrees.
With the same 26x2.0 tires I'm running, that gives us...
69.29mm trail with the 46mm offset fork @70.5 degree head angle for the 600S.
...vs...
62.93mm trail with the 52mm offset fork @70.5 degree head angle for my 560S.
The effect (*if* the head angle remains the same) is higher trail and more wheel flop at rest and faster-feeling low-speed handling and greater stability at high speeds (
http://www.thorncycles.co.uk/forums/index.php?topic=4245.msg19567#msg19567 ). Because head tube angles aren't listed for any of the new frames, we really cant accurately calculate trail, so the above assumptions are probably
incorrect, as I don't see Andy going with
that much trail. Probably the head angle has been steepened by a degree from 70.5 to 71.5 to recover a 63mm (63.08) trail. That's what I would do, anyway.
Still, I'd kinda hate to add another 25mm/1in in the top tube (taking it away in stem reach [8.5cm vs 11cm] would kill my stem-top mounting point for the GPS) and the standover height is
really too high for my needs at 50mm/2in higher, especially for more technical singletrack where I may dismount to the offside of a slope. I do like the familiar extra-oversize tubing and similarly long stays, but the rest is just "off" for me.
I think you right that you got lucky buying in 2011 and getting a tougher spec that fits you than you would now.
<nods, vigorously> Agreed, it feels more like "blessed" by the moment. To think I almost waited till this year instead of taking the plunge last August.
I'm really praying nothing (theft, damage) happens to my 2011 560S, as there really is no direct replacement for my needs. Sigh. Well, hopefully nothing will happen to mine for a very long time.
By the looks of it the 610 S is staying as it is still in that sizing chart.
Yep, and still intact in all measurements.
Thanks, Iain, it's fun talking about this stuff with others. Nice work.
All the best,
Dan.