Just discovered this forum for Tandem enthusiasts and have had a good time reading through the posts.
My name is David Bohm. I build custom frames under the name "Bohemian" and I look forward to discussing tandem issues from time to time.
I will keep the sales pitch short. I have always enjoyed making custom tandems and I hope that I can increase some of my business in that aspect by offering great inovations in the tandem market.
Recently at a show entitled the "North American Handmade bike show" A meeting of many custom framebuilders and over 700 bicycles. The second Generation Bohemian tandem was able to win not only the best tandem award but also the "peoples choice award". Attendes were able to vote for a single bicycle. I am proud to have won that award.
There are several interesting details on that bike. So what's the answer to the question that's in my mind? I'm thinking that if you have to ask, don't.
dbohemian
03-11-07, 10:08 AM
Ahhh, the 25 thousand dollar question:rolleyes:
Much like a concept vehicle at a large auto show, this tandem explores the possibilities if you will.
Although it is absolutely for sale or I would make another like it, my main goal is to offer a simplified version utilizing TIG welding or Fillet brazing and the spcial features of the integrated stoker stem, longer stoker cockpit, the sliding front adjustable bottom bracket and safety front drop outs.
Future, lower cost tandems will most likely include simplified assemblies, smaller tube diameters and pre-manufactured forks.
None-the-less, I am just one man working in a small shop and cannot compete with the economies of scale that some of the large tandem manufacturers can offer. Therefore, these tandems will always be a premium product, both in quality and price.
Dave
ghoundz
03-11-07, 10:16 AM
Hello David,
How long is the stoker compartment on that beautiful tandem; measured center of Stoker's seat post to center of captain's seatpost?
Just curious.
Thanks,
Jeff
caadman
03-11-07, 10:28 AM
Hey there David, these are some nice pictures and congrats on the award. I like that gold colored tandem you have here, man that's nice. But a few questions for you, are your tandem made of steel? and also, would you consider making a tandem from another material??
Thanks,
Benjamin
dbohemian
03-11-07, 10:50 AM
I will answer both the previous questions with this one.
The stoker compartment is just about 85cm long or 33.5 inches. Standard dimensions range from 68 to 72 or so.
The integrated stoker stem is integral to a length such as this, allowing a range of adjustability that would be difficult with other systems.
The tandem is made of butted oversized steel. Frame weights (less forks) on my tandems have varied from 9.5lbs to 13lbs on this one as it was designed to be a triplet someday. Considering that the couplers are quite heavy I was pretty happy with that.
I am sure materials have brought up very extensive discussions in the past. Let me first say that I firmly believe that any material, steel, aluminum, carbon, and Ti can be designed to make a wonderfully riding tandem bicycle. But....When I consider factors such as the ability to vary my design parameters, weight, reliability, ease of fabrication, stiffness and ride quality I have stuck with steel because I believe it to be the right choice.
If after all the number crunching, FEA analysis and hundreds upon hundreds of hours of design time I put into this, If I thought aluminum or TI would be a better frame choice I would pounce on it. IMHO steel or carbon are the best choices. I am pretty well versed in steel fabrication and I am not a carbon specialist so the decision was fairly straightforward.
With steel, I have been able to make very well riding, stiff, strong, beautiful and durable tandems that weigh in the low 30's. Who could ask for more:D
Rincewind8
03-11-07, 01:03 PM
Very beautiful tandem!
Some questions:
Is there a second BB shell at the stoker position? If so, is it for a variation of positions or for a different reason?http://www.bohemianbicycles.com/412557646_863370203e_o.jpg
Does the rear disc brake mount move with the rear axle?
Does the extension of the boom tube/keel beyond the captain's BB mount save similar amounts of energy/fuel as it does on big container ships and tankers? :D
dbohemian
03-11-07, 02:45 PM
Actually, I use full round 24mm track fork blades for the chainstays. There are no dimples, bends or flattening of the stay. This increases stiffness but makes for a couple of clearance issues. By pushing the attachment point back everything clears nicely.
Yeah, it does look somewhat like a keel on a ship:) that is one of the design aspects, The boom tube is completely uninterrupted by any other tube. In addition no one tube intersects another tube. This helps to ease fabrication and gives a full weld circumference to every tube leading to a more durable structure.
So this means I have to cap off the boom tube on either end. I thought the domes to be a clean way of doing it, plus you can store stuff in the boom tube as it is completely open for its entire length.
The whole aesthetic is very different than a traditionally designed tandem but it grows on you.
Dave B
regomatic
03-11-07, 04:18 PM
Beautiful bike.
Please tell Retro Grouch how much it costs.
I first visited your website through a link from S&S while researching a new tandem purchase. We decided to go with something more traditional, but we appreciate the effort and thought that you put into your designs and feel more educated from reading about them. Thank you also, for sharing your experience and knowldege with the tandem community through this forum.
dbohemian
03-11-07, 04:37 PM
Thank you very much.
I hope, given time that some of the designs that have been pioneered by the likes of Tom Bruni, Victor Chang and myself will show themselves to be the predominate design type. I think you may already be seeing this influence in bicycles from Co-motion to Calfee.
I already gave away the cost of this very special machine:D When I said "that is the 25 thousand dollar question" I was being very literal.
When the production oriented version is released it will have a price that is more in line with other premium tandems on the market.
When seen in person it takes some time to wrap you head around this bike. When asked of the price at the show, not a single person expressed surprise. Most were like "well, it looks like a 25k dollar bike"
Please though, do not think that I am only a builder of stratospheric bikes for movie stars or something. That is really not me. I just like to stretch my abilities once in a while and explore what is possible.
Dave Bohm
Bohemian
TandemGeek
03-11-07, 05:29 PM
Nice work Dave...
rjberner
03-11-07, 07:08 PM
$25,000???? GONG! Next, please...............and show this nice gentleman to the door.
galen_52657
03-11-07, 07:15 PM
How about a welded frame with over-sized tubing that dispenses with the 'work of art' aspect and can be ridden without the owner worrying about getting it dirt?
Oh, and reasonably priced.
dbohemian
03-11-07, 07:35 PM
Yes, absolutely, the end goal is to either have a welded or fillet brazed frame incorporating all the design aspects at a very much reduced price that is competetive with other tandems that are similar in quality and part spec.
Being a one man show and building to such a high level, it is not my place to compete with the likes of Burley and other budget oriented tandem manufactures.
As I said before, do not let some piece of show eye candy permanently dispose you from thinking of me as a viable option.
Think of it this way. If any of the custom motorcycles or rod guys had invested this level of effort, engineering and machining in a motorcycle they would fetch 150k for it. I am a relative bargain:rolleyes:
Some of the numbers to ponder. Over 700 hours of design and build time. lugs made of 2.125'' stainless inconel exhaust tubing at over 80 dollars a linear foot. 1200 in S&S couplers. The paint itself, not the clear or primer but just the color at cost 320 dollars for the shadeshifter. Even the leather handlebar tape was made by an Amish bridel maker. As you can see, things can add up quick:eek:
One thing that I always firmly believe is that all machines, no matter how fancy are meant to be ridden. It's only dirt, it can be washed off, paint chips can be filled and parts can be replaced. There is beauty in the patina that comes with age and use.
All the best.
Dave B
Bohemian
Jinker
03-11-07, 08:01 PM
Hi Dave, nice machine. While not partial to the show car or custom harley type machines or subculture, I can appreciate the craftsmanship and labor that go into those machines.
Your bike has the added appeal for me that most of the truly novel custom touches are done for a reason, to address one technical issue or another. Whether they get taken up as good solutions to problems, or end up being dead ends remains to be seen, unless someone makes an attempt, we'll never know. ;)
Congrats on the award.
zonatandem
03-11-07, 08:42 PM
Dave:
Seems like about a decade or so ago we were bending your ear about 'when are you going to build a tandem?'
Congratulations on your double award . . . well deserved!
Besides being innovative, you have the rare ability to mix craftmanship and artistry.
Felicitations from your fellow Tucsonans who 'occasionally' ride TWOgether!
Rudy and Kay/zonatandem
teamcompi
03-11-07, 10:31 PM
That is one nice bike, its a work of art with wheels. I am sure it looks great in your shop but some really rich person should buy it and donate to an art gallery, or to me! I am impressed!
galen_52657
03-12-07, 03:45 PM
I think the market will dictate weather or not you have a viable product. Personally, I think the utility of steel as a high-performance frame material has not been exhausted. But it has some inherent disadvantages which I have yet to see anyone fully address: Measured against other metals, steel is denser than aluminum, titanium and magnesium. Steel can be drawn thinner than those materials but when drawn thin enough to compete weight-wise, steel tubing will suffer from buckling. I think this could be overcome with corrugations of the tube which has been done before, but I don't see anybody doing it now.
As far as super high-end tandems go, that part of the market has some pretty heavy hitters. One can purchase a Co-Motion Macchiato with full custom frame geometry for $8000. That's a tough benchmark. Can you meet that bike's weight and performance at that price point?
dbohemian
03-12-07, 04:47 PM
I agree entirely. The customer always dictates whether a product is viable. Not the designer or manufacturer of a product. It is our job to inform the customer and hopefully, if our product has merit and we can convey our message, then the customer will give us the greatest compliment. An order.
Sometimes as we all know, great products fail because of a lack of advertising, or hitting a cord in the buyer. The internet is a great tool in helping the educational process.
With all due respect, you are basically accurate with the materials comments but of course, with all engineering concepts, it is not nearly as simplistic as you are making it out to be. I would gladly discuss material science and tubing geometry with you. Maybe another thread dedicated to such a thing would be more appropriate?
I believe that at the high end of the market, which is predominately served by very light racing machines may not be what all users are looking for. The optimum tandem or bicycle for a rider is not always the lightest most race oriented one. Factors such as proper fit, designing for a purpose (touring or special needs) riding comfort, reliability, quality of the build and uniqueness, may be more akin to what some teams are looking for than flat out light weight.
In addition with all respect to other manufactures like Co-motion and Santana, there is no way they can compete on a custom level with some of the top crop of small framebuilders. We are able to offer a level of fit, finish, education and customer service that is unobtainable in a production environment. Anything one can dream, I can provide.
For the select customer, the beauty is in the details.
Dave Bohm
galen_52657
03-13-07, 06:17 AM
Seems you want it both ways Dave. In one post you state "Yes, absolutely, the end goal is to either have a welded or fillet brazed frame incorporating all the design aspects at a very much reduced price that is competetive with other tandems that are similar in quality and part spec."
And in your above post you sound more like a boutique builder look for a niche market in the Rivendell mold. There may be a few folks out there that are willing to pay for the fancy lug work but by and large, teams with money to burn are going to look for the lightest frame regardless of intended use. And with two well-known carbon fiber builders able to offer full custom frames any way the customer wants, why would anyone opt for a steel frame that is 3-4 lbs heavier?
dbohemian
03-13-07, 07:06 AM
I am sorry Galen. It is sometimes difficult across the internet to completely convey ones thoughts and intentions.
Also, of course, I am not the builder for everyone, nor do I want to take away 25% of co-motions business next year. I am just a craftsman in his shop, making what I feel to be the finest bicycles that I can produce. If I had 6-12 tandem orders a year, I would be a happy guy. I have been a boutique builder since 1993 and in certain circles I am fairly well respected:)
Glen Erickson is one whom I admire. He produced (still occasionally) beautiful, high performance tandems. I hope that I can cultivate a small business as he did (he is very busy with his tandem touring company now)
You could also make the very same comments of my single bicycles but the fact is that builders like Richard Sachs, Sasha White, Myself and many others are doing O.K providing at least a small percentage of the buying public alternatives to commonly produced bicycles.
All the best.
Dave Bohm
P.S. I am not trying to fully evade your question but it may be more appropriate in another thread. In addition, I will quickly add that WEIGHT IS NOT EVERYTHING. I feel that some of my additions and frame designs make for a better performing bicycle exclusive of pure weight. (which you are correct, would be about 2 to 3 lbs more but be more reliable, stiffer and ride better IMHO)
masiman
03-13-07, 09:27 AM
If I had that kind of money, I for one would prefer a Dave Bohm (at least from the aesthetics point). I have no idea how they ride but if it could be made to ride to my preferences, I sure would enjoy having one under me. A couple of pounds on a tandem is fairly inconsequential given our riding style. My racing days are over much less I never have and likely never will race a tandem. If I were training for a RAAM or other time critical event, then yeah, the weightier elements would go. But for cruising, touring and general about town riding, I adore/covet/get excited for the uniqueness and beauty of Dave's creations. But I am just one beholder. I don't think I could ride Dave's Rohloff creation, way to pretty to be on the road :). Like something from the game Myst or the movie Steamboy.
My wife and I use to go to the Seattle Bike Expo in the 80's and 90's. The Rivendell's were our favorite stop to look at the museum stuff. I would have really liked the Handbuilt show.
I wish you the best Dave. I hope to see a creation or two of yours in person.
TandemGeek
03-13-07, 10:55 AM
There is a world filled with all kinds of enthusiasts and afficianados who appreciate craftsmanship, aesthetics, personal attention, customization, and exclusivity.
Fine art in all of its forms as well as more utilitarian or consumable "things" like finely crafted cigars, wine, single-malt scotch, time pieces, automobiles, motorcycles, jewelery, and yes, even hand-built bicycles and tandems, are all appreciated and often times coveted by their respective enthusiasts and afficianados. Such people routinely invest portions of their discretionary income on these types of luxury items for a variety of reasons and, ultimately, it's because they can.
For everyone else, there are many other choices to fit their value systems, needs, budgets and expectations. After all, having the lightest bike is often times meaningless if that's not the most important thing to a consumer. Of course, the conisouer with means does not usually have to make an "either or" decision and may elect to have "one of each." Then again, they are just as likely to take what others consider to be a work of art and simply ride the hell out of it because more often than not, the best looking bikes and tandems ride as good as they look. And, no, the most expensive bikes aren't always ridden by the fastest, strongest, or most skilled riders because, well, it just doesn't always work out that way. Just check the credentials of anyone who's recently wrecked their Ferrari, Porsche, or Bugatti.
Again, thankfully, there are enough other tandem builders who bring products to the market to fill all of the other consumer needs and budgets, which account for what I would suspect is well over 95% of the tandems that are sold. Oh yeah, and you'll also notice that several of those production houses are also doing their best to meet the needs and expectations of that "other 5%" with some pretty high-end offerings of their own. Personally, I cringe every time I drive past a Chevrolet dealer who lines up 60 Corvettes across the front of the lot or a row of Porches waiting for buyers to pick them from the lot... so much for exclusivity and personalization and Lord knows, few of them are being acquired for competitive use. So it is with many of the high-end, lightweight racing tandems.
Again, kudos Dave for your commitment to a 10-year dream, your innovative designs, and your artistic execution of those designs.
zonatandem
03-13-07, 09:23 PM
Dave:
What is he wheelbase on that tandem? Our guestimate is around 75 inches.
Will you be showing it off at the GABA 4th Ave swapmeet on April 1st?
Would give you some great exposure to about 4 to 5,000 bikies that usually show up for that event.
Many folks lust for a custom bike . . . quite a few eventually do own one.
Keep up the great work!
Pedal on TWOgether!
Rudy and Kay/zonatandem
Fenlason
03-14-07, 01:53 PM
Dave welcome to the forum. Beautiful work.... and I am sure the pictures do not do it justice. While I could not have given any specifics, I have heard of your bikes before.
There are plenty around who appreciate this kind of work. There are also still plenty that know the benefits of a good steel frame. While I also have bikes of other materials.. and really liked some of them, most of my favorite bikes have been made of steel.
Of the 3 tandems I currently own. One is aluminum, One is ti-carbon, and one is a custom steel bike. It was made by Jeff Shugg of Calgary [he is no longer building].