Double top tubes
 

I'm looking for a not too expensive lugged steel frame to build into a "fast" commuter bike. I thought I narrowed it down to the Soma Stanyan, but I just saw they also have something called a san marcos that looks pretty nice too.

One thing I don't get is the double top tube on the larger sizes. Seems to be something Rivendell bikes does but plenty of other makers of larger frame sizes don't do this and even the Soma Stanyan doesn't. It says it's to "restore the triangulation lose with the tall top tube" but I don't see any loss of triangulation in other "tall" bikes. What are they talking about?

One a more general note, any thoughts on which of these would make a good commuter bike for 30 mile RT rides with just a rear rack and maybe 20lbs or less of "stuff" to haul? I will put on a drop bar and compact crank with probably an Apex 11-32 rear cassette. I will most likely get a 60cm (Stanyan) or 59cm (San Marcos). Geometry on the Stanyan seems more agressive with the short HT but not sure I care about that.

Thanks.

Your two choices are certainly very nice frames and they fit the bill of being both lugged steel and capable of commuting. I personally have no experience with either of those two frames, but I do have a fair amount of experience with older lugged frames that have proved quite suitable for commuting. I would personally suggest checking out the used options in your area, a great many deals are to be had out there on used road bikes of the lesser known or smaller makes that are nonetheless top-notch bikes when built up properly. My suggestion of seeking used bikes comes from my having been raised thrifty, my current status as a student, and my love for pre-owned things that have already developed a "personality" of their own. However, if you prefer more modern options I can offer little beyond Soma's and Rivendell's options. You may also consider looking into Velo Orange Rando frame which is also lugged steel and suitable for you needs. Good luck!

Cheers
lverhagen

I love the San Marcos and the Stanyan. In particular, I love the lugged chromoly frames. The lugged crown of the Stanyan is absolutely an exquisite delight to behold. I can personally imagine the installation of chrome chain stay covers as well as possibly chrome-colored; handlebars, stem, crankset, and pedals.

- SOMA has really over done it with these beautiful frames!

PS.



I don't quite understand the double top tubes for the larger San Marcos frames though...Seems just a bit quaint!

The headtube on the San Marco is 200+mm on the 59 and 63cm frames which are much longer than those on the Stanyan.

Maybe this helps a bit. The line beyond the head tube for the upper top tube is 2/7th the length of the upper top tube. Given the distance from the upper top tube to the down tube, the forward triangle is more like a trapezoid instead.

http://img12.imageshack.us/img12/5697/somaxb.jpg

From what I know, the extra tube is there to protect against frame flex (and sometimes break) for taller frames and riders.

It's an old fashioned solution to stiffening large frames back from when the only tubing was standard 1" diameter. It also allows a large frame to be built in a lugged fashion.
If you are looking for a particular style, its an OK solution. If you want the optimum design, it will have to be in welded, oversized tubing.
An oversized head-tube using a modern standard size will be stiffer and require less support in the large sizes.

I think they would have put in a double top tube on the smaller frames if it would have fit. It's just for style points

Thanks for the feedback. I guess it's just a Rivendell thing. Personally, I don't care for it as it makes a large bike just that much heavier. The 60cm Stanyan doesn't have the double tube while the 59 San Marcos does. Maybe it's the really tall HT on the SM. I'm leaning toward the Stanyan mostly on look and price but that one has an overly short HT. Don't see why they can't do something in the more average range.

I didn't know steel frame tubing came in larger sizes. I thought it was only aluminum that they could do the large oversized but thin walled tubes. Maybe it's just a weight thing. Oversized steel would probably be heavy.

yep, oversize makes a lot more sense

two tubes is heavier

Which is what I would expect. This begs the question, though, is the Stanyan using oversized tubes or is it just a weaker frame because it uses 1" and no double tube? Head tube is 1 and 1/8" but don't about the rest of the frame. At 190 lbs plus gear, I don't want a bike that isn't up to the task (although most steel bikes can take a lot of abuse, I don't want to abuse my bike).

I hate the way double top tubes look. I would prefer that they build the frame out of stronger material, or make the top tube of a greater circumference. Of course this is just my preference.

I'm not a big fan of the look of double top tube frames either, but it's purpose is definitely to reduce frame flex, while maintaing the same tube diameter. This issue can be addressed other ways via larger diameter tubes or sloping top tubes. My guess is that some manufacturers utilize this method as a point of style, giving a nod to "old school" technique. The Pashley Guv'nor uses the same technique. For me, I'd try to make the smaller frame work and address the sizing issue with a longer seatpost (with setback if necessary) and a longer stem.

If you're not carrying 50lbs of cargo it's hard to imagine the double top tube being useful. It's not going to break, it will flex more. If 90% of the time you're carrying less than 20lbs, I'd go with the Stanyan.

Looks like the perfect place to store a frame pump without it getting in the way of bottle cages or other gadgets. Just sayin'

It used to serve a function, but now it's really just a style thing. I have a Kilo OS, which is fun (mine's mostly not stock). If you like it, you like it. If you don't, you don't.

http://dl.dropbox.com/u/13487871/KILO_OS/FULL_VIEW.jpg

My Touring frame put 2 tubes side by side, took care of the rear rack-load flexing the top tube .. the 2 tubes .75" .o49 wall also functioned as chainstays and seatstays.

I see Trek has a single speed the 2 tubes are the seat-stays , then miter into the head tube

they gusset the seat tube, and add a bottle opener, in the back
My build, a collaboration, kept them parallel, passed by
attached to the side of the head tube then got gusseted there behind the head tube.
frame fit tire pump sits between the toptubes..
I cut down a 'church key" added it to the side of the left seat tube.

I guess that I am the only one who thinks the double top tube looks much nicer than a single oversize tube. I think they look very cool.

Mike

Kind of my thinking too. Just have some concerns about the short ht on the stanyan. Might try to find one to look at in person.

You mean something like this?

http://www.somafab.com/wp-content/up...fixedbuild.jpg

That's how a C&V frame goes, maybe the ES is a better choice?

We discussed this head tube issue for the Stanyan on the C & V forum a little. There you will find pictures of my Stanyan build.

http://www.bikeforums.net/showthread...el-Frame/page2

Personally I dislike the double top tube design. I think it's ugly.

The Soma Stanyan frame and fork is a beautiful piece of work if you like beautiful black paint and chrome lugs like I do. Judge for yourself from the photos. Regarding the short head tube, as I said in the thread, I don't see any problem functionally. Maybe an aesthetics argument could be made.

Thanks for the tip. How tall are you? given that seat height on a 58 I could run without most of the spacers and be happy but I'm 6'3" and expect I'd have the seat higher. I'm thinking a 60 might be the better choice for me even though my caad is a 58.

I'd be curious to know some of the build specs too - especially brakes and headset.

I'll toss this one in.

I use it for everything. from commuting, to touring. to last year's attempt at the Tour Divide.

Double Top Tubes.

Seat tube length isn't my critical dimension, I am more interested in effective top tube length, reach and stack. At 6"-3", a 58cm frame with level top tube might be too short on the stack and reach. What is the ett length of your caad? What is the seat tube angle compared of your CAD? Is the top tube level on a caad?

Hey there AsanaCycles,

I generally don't think of Cruisers as Double Top Tubes, but they are! They really are!!!

That's interesting how I've never quite viewed them in the same manner, before.

However, actually the typical Cruiser, is the original Double-Top-Tube.

Ha!... It's really the progenitor of the San Marcos!

Thank you for this!

- Slim :)

PS.

Funny, I've always liked the Cruiser-type bicycles!

However, the larger Double-Top-Tubes, like the San Marcos appear to be rather odd-looking...

I am about 5'9" or a little less. My pubic bone height (inseam) is 32 inches. I ride bikes from as small as 54 cm to as large as 60 cm although my ideal size is probably 56 cm. The Stanyan is a 58 cm.

Regarding the build specs, let me post that later after my morning ride when I have a little more time. I will also post some pictures showing details. I have many.

I think that specific cruiser needs the 2nd top-tube to store the dilithium crystals

Yes! Post lots of pictures! I am saving up towards an ES but the Stanyan is beautiful.

Regarding the issue of Soma Stanyan head tube size. I just did some measuring on a couple of my bikes. My Stanyan is a nominal 58 cm frame but the actual center to top of top tube measures close to 57 cm. The head tube is 140 mm long. I have an old 1982 Trek (read about it here: http://www.bikeforums.net/showthread...43-My-old-Trek ) that measures 58 cm center to top of top tube and it has a head tube length of 145 mm.

These are so close that I see no real difference, especially considering that the Stanyan frame is slightly smaller c - t.

Love double top tubes, but I'm nowhere near tall enough to actually fit a frame that has it. Prefer the truss frame:

http://antbikemike.files.wordpress.c...pg?w=640&h=480