Soma San MarcosMay 2013: A review in Bike Times.
This is a bike we were commissioned to design for Soma Fabrications of San Francisco, for distribution to its many dealers. We’re friends with the SOMA people, and they wanted a Rivendell-designed bike. As part of the agreement, we were (not surprisingly) allowed to sell them, too. In our line it fits in close to the Roadeo, but has a bit more all-aroundedness to it, by virtue of its rackability and tubing (less racer-light than the Roadeo’s). A frame costs $900; a complete bike, around $2500, depending on the parts.
In the mid-‘70s to early late ‘80s the Soma San Marcos would have been called a sport-touring bike; more comfortable and useful than a racing bike, capable of carrying moderate loads, but without the extra stoutness and load capacity of a full touring bike.
In other words, it’s a useful road bike that you can stretch in a pinch.
The San Marcos has light tubing for zippiness on the road, and fits fenders and fatter road tires than the usual dry-road/skinny tire bikes, so you can ride it all year around, on any road surface, and even smooth trails. It has two eyelets for fenders and a rear rack, so if your plans call for a 20-pound load, you can carry it.
The top tube slopes up about 6 degrees, raising the stem’s exit point, and letting you get the handlebar higher, easier. It’s way more comfortable that way, and there are no drawbacks. It doesn’t lock you in to a super high bar; it just allows more comfort, should you want it.
You should want it. Why not?
Let’s talk about comfort
Comfort doesn’t come from the frame material, anti-vibration handlebar plugs, or even fat, cushy bar tape. It comes from high handlebars, and low-pressure tires. A typical road bike today puts the handlebar several inches below the saddle. That’s no place for a drop handlebar, but it’s where most of them are on normal bikes. The San Marcos (like all of our bikes), lets you raise them and feel good.
The comfort difference is so dramatic that you’ll notice it within five seconds of your first ride. It’s not subtle. This first impression is also a lasting one, and you’ll be way more comfortable after 80 miles on the SM than you will be on any normal road bike—an inevitable consequence of the higher handlebars. They take weight off your hands, de-compress your arms, make it easy to see without craning your neck, and you won’t have to lean forward as much, so your back will relax more. You know how, now—on your current normal road bike—you hardly ever ride the drops on your drop bars? They’re too low. It’s akward to get down there and uncomfortable to be there. It's different on the SM.
The fatter road tires the San Marcos fits contribute a lot, too. Higher volume allows lower pressure. Instead of riding around on 23mm tires pumped to an iron-like 115psi, you can ride 32mm tires pumped to 80psi, or 35mm tires at 65. The comfort difference is huge. The tire rolls over a driveway lip or a chunk out of the road, and it deforms, absorbing the blow. This is the way tires are supposed to work, but modern road bikes fit only skinny tires that have to be pumped up too hard to do this.
Does comfort mean slow?
No! On rough roads a softer tire is faster, because it deforms over the bumps and rolls right on through them without getting bounced. And when the tires don’t get bounced. you don’t, either.
A final component of speed is comfort.
A comfortable riding position and comfortable wheels let you put more effort into any ride, and effort, not hardware, is what gives you the speed..
What a nice fork the Soma San Marcos hasIt has a flat-shouldered fork crown with swirls at the sides, and a swooping bat-wing on top. The blades are slender, of traditional steel-fork proportions, and the overall look is pleasing. Since it’s a roadier bike than our other models, it has what used to be known in the trade as a banana-bend—a popular racey bend from the ‘80s.
But the main thing with the fork is its clearance. You can easily fender a 32mm tire on it. Without the fender, you can fit a 35mm tire. This means you can ride the San Marcos in all weather, and on roads that are entirely unsuitable for the common variety modern road bike with 25mm tires.
The fork is steel, too, and that’s a great thing. A steel fork is safe when it’s new, and safe ten, fifteen, even 20 years down the road. Even more. A steel fork won’t necessarily last 100 years, although if you ever have the opportunity to ride a 100 year old fork, it will be steel. (If you ever have the opportunity to ride a 10 year old carbon fork, pass.)
The fork is threaded, too—another huge benefit. Threaded forks use quill-type stems that make raising and lowering the handlebar so quick and easy. The quill stem should never have gone out of style. There are no drawbacks to the quill stem. They’ve worked for a century. But you have to be comfortable riding a stem that’s not like the stems your friend use. This kind of stem is better. You may doubt that because when you look around, you see 99 percent of the bikes have threadless stems. They’re way easier for manufacturers to deal with, but that’s another story. For you, a bicycle rider, the versatility and vertical adjustability of a threaded headset and a long-quill stem are plain better.
The best stems, and the ones to get, are the Nitto Technomic Standard (225mm quill) or Technomic Deluxe (180mm quill). Stem extension is always a guess, but women should start with a 7 to 8cm extension; men, an 8 to 11cm.
Turning the frame into a complete bike is easy.The San Marcos is compatible with any road or touring group from the past or present. There’s nothing you can’t put onto it. Let us work with you and put together a parts package ideal for your kind of riding. The complete bike will run around $2,500, and will be an untouchable value.
Technical & TriviaFrame fittings. All the lugs, the crown, and the BB shell are our own investment cast steel. The tubing is Tange Prestige (heat treated, butted CrMo). There was no conscious effort to make the bike compete in weight with carbon bikes. It is likely to last five to twenty times as long as a carbon bike, though, and under harsher conditions, will be a safer bike to ride. That said, there’s no gratuitous fat on the frame or fork. They weigh roughly 4.5 lbs and 1.6lbs respectively, compared to maybe 3lbs and 1lb for a same-priced carbon combination. Given that the engine that’ll provide the power weighs 120 to 250 pounds, the 2.1 pound frame and fork difference is insignificant.
Value comfort, want good looks and longevity, and get over the insecurity that sometimes comes with riding a bike that none of your friends have heard of and you won’t see advertised in the bike magazines. The SOMA San Marcos is the best value in a sporty-versatile road bike today. By modern standards and pricing, it is untouchable.
The extra top tube. Yes, this is an obvious feature of the 59cm and 63cm SM, and it has un-obvious benefits…until you understand triangulation. Triangulation is what gives bike frames, and for that matter, almost every man-made structure from buildings to bridges to electrical towers to loading cranes, their incredible strength—despite their spindliness. A triangle is as close to magic as a geometric shape can be—right up there with the circle.
Bicycle frames are asked to carry fifty or more times their weight over a variety of terrain for many years, and they’ve always performed this task with triangulation. BUT…they lose triangulation as the frame’s head tube grows, as it does as the frame size increases. The 59cm and 63cm SM have long head tubes (which help get the handlebars up), and so, to re-establish the triangulation of a much smaller frame, we stuck in a second top tube lower down, and brazed it in place with two beautiful lugs. The added weight is about 8 ounces—a pittance compared to the structural benefits it offers. The frame’s strength and resistance to fatigue is increased, and there’s less lateral flex. It may benefit heavier riders more than flyweights, but it is, in any case, a better way to make a bigger frame. Some riders don’t get it, or don’t think it’s cool, or classic, or it’s just too much of a shock to their system. But it is a better way.
The frame comes in five sizes:
47 - 51 - 54 (650B)
59 - 63cm (700c)
The 47, 51, and 54 are designed for long-reach brakes, with a reach of about 60mm. You'll use the BigMouth 73s or Silver sidepulls, or a Paul or DiaCompe centerpull with that much reach. These brakes rather than the med-reach sidepull, because of how the seat stay angle affects clearance. It's a quirky detail of frames, largely unknown, quite real, and the best way to deal with it is the way we've done it---with a longer reach. This explanation is short on purpose, because it could be 800 words by itself and still not convey the physics of it.
The actual geometry........well, I don't have time to put it up, and I'm not super-inclined to, anyway. There's nothing magic or dumb about it. It reflects all of my 'pinions about frame design, with no cave-ins to anybody, and it designed just the way I'd've done it for us. I like long chainstays, high head tubes, lowish bottom brackets, good clearance, shallow seat tube angles, moderate head tube angles (better handling with high-er bars) and trail. We've built and ridden the bikes here, and they ride as well as any bike I've designed.
Price: $900 frame and fork. Whole bike: From $2500 to $2800, typically. It's one of those "a la carte" deals, where you can go cheap or glitzy. I'd recommend the same kind of stuff we put on our other bikes---Sugino XD crank, Nitto wherever possible, nothing smaller than a 32mm tire (you can put a 22 on it if you want, but why would you want to?).....that kind of thing. A whole bike could easily be had, without anything crummy, for around $2.1K, give or take.
Color: Tiburon blue.
Availability: 59 - 63cm (700c), 47 - 54 - 51 (650B) - We order them as needed, no stock is on hand.
Getting the right size is easy:
It always starts with your PBH (pubic bone height). As a backup or a cross-reference, you can use an existing saddle height (SH) (center of crank to top of saddle)---but only if you know it to be correct. Now, here we go.
If your PBH is Then your SH should be and your San Marcos size is
73 to 77 62 to 67 47
78 to 81 68 to 71 51
83 to 86.5 72 to 75 54
86.49999 to 92 76 to 81 59
92 to 96 81 to 85 63
These are conservative ranges. If you PBH is on the lower end of the frame-size range, you'll still have plenty of crotch-clearance, but the seat post won't stick up as much (you'll show a fistfull of post). If the numbers are foreign, don't sweat it, we'll work it out. But it's really good to know your PBH, and you can learn how to measure it here.
To order: 800 345-3918. Mark is our resident SOMA expert. Ask for Mark.
We'll ask for frame payment now, and then, if you want a whole bike, we'll figure out the best parts for you. You don't need to know any tech stuff about bike parts. If you do, and you know some or all of what you want on the bike, that's great. But if not, just tell us what kind of riding you want it for---presumably all-around road riding and not a lot of trail riding, and no tire bigger than 35mm wide---and we'll ask you some questions only you can answer, and that you WILL be able to answer.
Of course, you can call and talk about the bike without anybody pushing you into it.