Wednesday, September 15, 2010

rSogn Sizes

Here is an updated geometry and drawings of the rSogn in all three sizes with a 25mm head tube extension and less slope.

rSogn Geometry
Click on the table to embiggen.

Click on the drawing to embiggen.

Click on the drawing to embiggen.

Click on the drawing to embiggen.



Anonymous said...

I like the less sloped tt, which was created by lowering it on the ht (since that measurement remains constant from yesterday). I was initially puzzled as to how this would raise the standover, but I'm assuming yesterday's SO numbers were not based on the 58, as they are today. Is this correct?

This looks fantastic.


frank_a said...
This comment has been removed by the author.
Russ Stringfellow said...

More slope please!

One of the great advantages of the 650b wheel size is that it allows stubbier-legged riders the ability to reap the rewards of bigger wheels without the extreme frame tweaks required by 29er wheels.

A "slopier" top tube will still allow room for short legged folk to take the rSogn off-road and keep the main triangle big enough to stuff a frame bag inside.

While I'm begging, how about disc brake compatibility? With the UCI allowing discs for competition, it's only a matter of time until someone makes a drop bar hydraulic lever.

Sean said...

@Russ: I know exactly what you need. Do email me at


Sean said...

@Mark: The SO measurements are based on the Neo Moto 2.3/58c. With the slope as is, the rSogn would still look proportional in 52c, 42c, and even 38c. Here are SO numbers for these tire sizes in each frame size:

MD: 52c tire (83cm SO); 42c (82cm); 38c (81.5cm).
ML: 52c tire (84cm SO); 42c (83.5cm); 38c (83cm).
LG: 52c tire (85cm SO); 42c (85cm); 38c (84.5cm).

Russ Stringfellow said...

Sean, thanks for the feedback. Check your inbox.

alex wetmore said...

I like where things are ending up. It seems like the head tube length could go up the same amount as the seat tube length though, leaving the top tube slope the same across models.

Protorio said...

I like this very much. The M/L and L have nice, minimal tt slopes. I also like the more traditional head tube extension. LIKE! Please keep the TT slope like this.

Jim G said...

I'm 5'10" with about an 86cm PBH in bare feet. Which size would I need?

alex wetmore said...

Jim -- I think we ride about the same size bikes, and I'd be getting a M/L. I'd suggesting sizing these frames based on top tube length.

On the M/L the bars will be about 3cm higher than a square 58cm road frame for the same number of spacers. For me that I means I could run the rSogn with 2cm or less spacers, compared to 5-6cm of spacers that I ran on my Kogswell D58 with a flat top tube.

If you feel like you normally prefer a longer top tube then the L would be good. Standover and handlebar height between the M/L and L don't change that much, but the L is significantly longer in the top tube.