pamaguahiker 

I have been wrestling with the idea of turning my Bianchi cross bike back to simply cross and building up a touring/rando type using some of my parts that I know work best for me when touring and rando type rides. I am presently using my Bianchi cross specific bicycle for touring type rides. I do note that with a load, it still rides nicely but feels sluggish at times and front heavy which is why I am steering towards a more rando specific frameset. I especially have been looking at several models and the new Soma Grand Rando has my attention. Of course, the factor coming up is the tire size of 650B which is the only option for the soma grand rando.

I haven't tried a 650B at all for any amount of riding time. But I stood over one that was 'my size' as stated by someone who was an enthusiast for the 650b. And It just felt low and small. I rode it only briefly, so i cannot give it a fair review. It might just be that way because of what I am used to riding but I was wondering, at 6' tall (inseam about 34), will the 650b feel too small for me? Or will I be just as well to continue to run 700c wheelset.

When I did ride the Bianchi as simple cross, it was a fast, sweet ride and I think it would make a awesome crosser again and also use for the 'New' catchphrase niche gravel grinder type bike. Which, BTW, I feel that my cross would handle just about any of that terrain, just as it did years ago before those words became a new type of cycling.

Tim_Iowa

What do you mean by feeling "too small"? Is the bottom bracket too low on the 650B bike? This sometimes happens when a 700C bike is converted to 650B.

A frame that is properly designed for 650B (as the Soma GR will be) should have the bottom bracket height roughly the same as on a 700C bike. Now, different frames have different bottom bracket heights. Roadies have low BBs, MTBs have high BBs for more ground clearance.

I'm 6' tall and I ride a 650B-converted Rivendell. I converted it to 650B because I couldn't fit bigger than a 700x28C tire. The bottom bracket is now pretty low on 650x38B (it's 28mm lower than before). I like it. However, I will occasionally scrape a pedal when I'm really leaning into a turn.

The 38mm tires (GB Lierre) feel twice as cushy as the 28mm tires (Rivendell Ruffy Tuffy), and just as fast.

I guess the question boils down to: what tire width do you want? I've heard folks complain that big 700C tires (50mm+) make the bike feel like it has tractor wheels, and it doesn't handle as well. I can't corroborate; 700x28 has been my max. If you want to ride medium-fatty tires, 650B might give you perfect handling. If you like medium tires (32mm or less), 700C might feel better.

But since your question is all about how these bikes feel, you're just going to have to ride test them to be sure.

dbg

Only half of 28, and you gain some back with a bigger tire. I converted a roadie to 650B and love it.
And feeling tall in the saddle also increases your wind resistance.

[correction: half of 38 (difference between 700c and 650B) which is 19mm]

pamaguahiker 

You make a good point regarding the soma gr being designed for the wheel size and most likely will have a BB closer to what i may feel as normal. And you also make a point regarding the bike i did stand over and the one i took for a spin. It was a convert from 700 to 650. I am looking for a tire size of around 30-35mm. I want a bit more width for stability and variety of road types. I am pleased with my Vittoria Rando tires i am running now on my present Bianchi. But i am well aware that the GB Lierre and ruffy tuffys are well worth the cost for comfort. I mainly was running the vittoria randos for durability and convenience at the time i got them. One of the main reasons i am considering the Soma GR was because my current ride is very unsteady with a handlebar bag. It's a cross bike and it doesn't like the handlebar bag weight on front. So i am thinking that the combination geometry will work very well for me. And then came the main question about it. It's only available in a 650b. So i just had to pry out the details on whether i would like the 650b before i lept into the project.

As far as sitting up tall in the saddle. You are definitely correct, but i am also finding that with age, old injuries, aches, and pains. I don't mind sitting a little higher, and the view is great too! Thanks for the feedback.