Soma Buena Vista Mixte

[furryblue]

Michael - I'm 5'8" and have no issues with fit on any of my 4 "boys" bikes.

Let's try and make this quantitative - if it's a bike model with published dimensions (Surly, Gunnar, Soma) let me know and I can calculate and compare the dimensions with the Buena Vista. I think when you look at the geometry specs you are perhaps not properly factoring in the effects of seat tube angle. Give me some numbers and we can calculate and compare.

[KnottedYet]

Surly 52 cm Cross Check.
Brooks B67 slid back as far as it will go. Approx 5 cm seat post out.
Dimension 120 degree stem on the standard cut steerer tube. (3 0.5cm spacers) Moustache bars with the bar ends at just about even vertically with the steerer. Top of bar (top of stem) nearly even horizontally with top of saddle.

I tend to prefer 175mm cranks due to my preference for mashing, and my femur length and difficulty getting a good KOPS. BTW, don't discount KOPS/Pat-to-Met just cuz some whippersnapper wrote an article "disproving" it. If you read what he has to say, it actually boils down to KOPS/Pat-to-Met. I got pretty grumpy after reading that article...

If I get a Buena Vista I would either have moustache bars or Nitto All-Rounder bars put on it. The All-Rounders would certainly shorten the cockpit. I like both these bars on my bikes that have them. (My 1987 Giant RS940 has All-Rounders. I'd like to convert her to 650b wheels, she'd be perfect for that with her low brake bridge and fork. If I do that, I'll also have her powdercoated, which means spending enough money in all that I really can't afford a Buena Vista. )

If you have the time and interest to compare fits of the CC vs. the BV, go for it! I'd be interested in seeing what you come up with. There are other Surly riders who also might be interested. (but I really shouldn't buy another bike right now... but it'd be interesting to see how they compare... oh, but I *really* shouldn't buy another bike right now)

[furryblue]

Surly 52 cm Cross Check.
Brooks B67 slid back as far as it will go. Approx 5 cm seat post out.
Dimension 120 degree stem on the standard cut steerer tube. (3 0.5cm spacers) Moustache bars with the bar ends at just about even vertically with the steerer. Top of bar (top of stem) nearly even horizontally with top of saddle.

Wonderful - I'll work up some numbers later.

[furryblue]

Surly 52 cm Cross Check.
Brooks B67 slid back as far as it will go. Approx 5 cm seat post out.
Dimension 120 degree stem on the standard cut steerer tube. (3 0.5cm spacers) Moustache bars with the bar ends at just about even vertically with the steerer. Top of bar (top of stem) nearly even horizontally with top of saddle.

Hi KnottedYet, Sorry for the delay in this response.

I hope this is not to much detail, I'm going to compare two sizes of the Surly Cross Check with the small size Buena Vista. I used the BikeCAD applet and some educated guesses to come up with the numbers.

Let me start with the 52 cm Cross Check. I calculate it has a front center of 590 mm. I believe that is about as short a front center as is really desirable for medium width (say 700 X 35C) wheels. To "normalize" the reach, I calculate that if the seat tube angle of the 52 cm Cross Check was changed to 73 degrees, then the effective top tube length (giving the same front center) would be 551.9 mm.

By the way, it's just a guess, but looking at the drawing and with a 110 X 120 degree stem, I'm guessing your saddle height is about 680 mm which sounds a little low for someone who is 5' 8"

Now let's consider the 50 cm Cross Check before moving on to the Buena Vista. It has a 542 effective top tube with a 74 degree seat angle which yields a front center of 589.3 mm. Notice the front center has only changed about 0.7 mm, and if we "normalize" to a seat tube angle of 73 degrees then the effective top tube is 551.2 mm, only .7 mm change. So as far as reach to the bars and front center goes, the 52 cm and 50 cm Cross Check are virtually the same. The reason is the design is hitting the constraints of the 700C wheel size.

Finally, let's go to the 50 cm Buena Vista. I calculate it has a 583.0 mm front center which is a little short in my opinion for the larger 700 C tires, and an effective top tube length (normalized to a 73 degree seat tube angle) of 545.5 mm, so 6.4 mm less than the 52 cm Cross Check - that's like a quarter of an inch, so we are talking small differences here. Now, the Buena Vista also has a longer head tube, so even though the frame is a smaller size (50 cm BV versus 52 cm CC), it is easier to get the handlebars up high. I calculate that you (KnottedYet) would achieve the same reach the to the handlebars and same handlebar height with the 50cm BV by switching to a 100 mm X 0 degree stem and eliminating 5 mm of spacers.

By the way, a fun and useful tool for stems and so on is here:
http://alex.phred.org/stemchart/Default.aspx

In conclusion, the 50 cm Buena Vista would fit KnottedYet about as well as the CrossCheck just in terms of reach to the handlebars - the effective horizontal reach is about a quarter inch less but head tube is taller so it's easy to get the bars higher and so the stem changes to a flatter and shorter one.

The Buena Vista has a nice low bottom bracket which I think is better for a road bike (the Cross Check is a bit high at 66 mm compared with 74 mm for the Buena Vista). However, there are some aspects of the Buena Vista geometry that are less desirable than the CrossCheck if we assume the CrossCheck is a good fit for KnottedYet:

i) the Buena Vista has a steeper seat tube angle and so you would need about another cm of setback in your seatpost to achieve the same saddle/crank relative position. Since you state you are already all the way back on the rails with your current seatpost, you would need a different seatpost.

ii) toe overlap will be somewhat increased and if you want to run larger tires and or fenders you might be less happy than with the CrossCheck

iii) although both the BV and the CC have the same head tube angle and the same fork rake, the handling will be a little different because of the weight balance and wheelbase: the BV has a shorter front center (puts more weight over the front wheel), and a longer rear center (also puts more weight over the front wheel), so if the Cross Check feels properly balanced then the Buena Vista won't feel as balanced. The balance issue will be more pronounced if you stick with your current seatpost and position your entire body more forward with respect to the cranks.