Hi Damon, Quick question, based on what you told me in the post below. I have checked the measures again carefully and stand over clearance in not a problem now as it is more than 10mm.
So from your point of view what do you think would be better for me a 51cm frame or a 54cm. Based on availability I could get a 54cm quicker but I want to make sure i get the best fit. Im currently riding a P3 51cm but from your options below seems that the 54 suits me better.
Cheers,
Rick
damon_rinard wrote:
Hi Rick,
You are normal :-), in that most everyone will find they can fit more than one size. You've nailed your two best options:
1) 51cm frame with High V aerobar
and 15mm of aeromatched fork spacers or
2) 54cm frame with Low aerobar
and 45mm of aeromatched fork spacers I've added the number of fork spacers each set up requires (in
bold), as some people have strong feelings about them.
Also consider that, for the same arm pad stack, the basebar will be relatively higher on the "Low" aerobar and relatively lower on the "High-V." (Low and high describe the elevation of the arm pads above the base bar.) Technically this shouldn't matter much since you should be in aero most of the time but again some folks feel strongly about it.
If you can accept 5mm more arm pad reach there is a third option:
3) 54cm frame with High-V aerobar
and 0mm of aeromatched fork spacers By the way: some measure arm pad reach to the back edge, we measure it to the center of the pad, so double check that we're using the same protocol. The Aduro arm pad is about 9cm front to back so use 4.5cm to convert if you've measured to the back edge.
Regarding comparing the geometry of the P3: We started the P5 with P3/P4 frame stack and reach, then added 25mm of head tube. This change (together with the larger bottom bracket drop) accounts for all the "apparent" differences in top tube length, stand over and frame stack and reach. To answer your specific questions:
1. The P5 top tube length is only shorter because of the added frame stack; the head tube axis is no closer than the P4 or P3. The change in seat tube angle isn't in the frame; we've designed the P5 seat post with a little more adjustability so the forward position gained us the 1 degree. Basically you can ignore top tube and seat tube angle and refer to arm pad stack and reach instead (as you've correctly done already).
2. Exactly right: the P5's added frame stack (and decreased frame reach) is precisely equal to replacing fork spacers with frame head tube. In your case the ~10mm of standover clearance might be a good reason to chose the smaller frame.
Max width of the Aduro arm pads is 205mm c-c. Some prefer wider arms, so 3T will be making extender plates. That said, the two M5 arm pad bolts are 25mm apart (c-c) and arranged front and back (not side by side), same as some other aero bars, so it may be that some existing extender plates from other brands could work as well.
Cheers,
bought S3 last year there.