Some tandem makers offer fillet brazing as an (expensive) option. Anyone know if it is stronger or just nicer looking than welds?

Anyone know if it is stronger or just nicer looking than welds?

It's all about the aesthetics... and you're paying for the fabricator's skill and time.

You really have to consider everything together. Sometimes the tube set dictates the joining method. Some tubes can't handle the heat required by welding very well and some thrive on it.

Having said that filet brazing, in my opinion makes a beautiful looking frame but it's likely to weigh a little bit more because of the amount of brass used.

Beauty is in the eye of the beholder.
We have owned silver brazed lugged frames, one fillet brazed frame and now a lugged c/f frame.
To us the aesthetics are worth the extra cost as we face our tandem daily. Is it a a 'stronger' frame? . . . not really. The skill and experience of the crafstman is what counts in the long run, no matter what the joining method.

You really have to consider everything together. Sometimes the tube set dictates the joining method. Some tubes can't handle the heat required by welding very well and some thrive on it.

Having said that filet brazing, in my opinion makes a beautiful looking frame but it's likely to weigh a little bit more because of the amount of brass used.

Fillets will add strength to a potentially weak area of a frame. With the current trend towards lighter frame and tube sets, some of the joints could have a weak spot around that area. Putting a fillet in will strengthen that area considerably, without having to resort to a thicker tube in that area. For example, the head stock to downtube is one of the more common areas to be strengthened in this manner.

Fillets will add strength to a potentially weak area of a frame. With the current trend towards lighter frame and tube sets, some of the joints could have a weak spot around that area. Putting a fillet in will strengthen that area considerably, without having to resort to a thicker tube in that area. For example, the head stock to downtube is one of the more common areas to be strengthened in this manner.

Can you provide a source for this use of fillets and/or steer me towards someone who's using fillets in this manner? I only ask because this is the first time I've heard of this suggested use of a fillet vs. a lugged or TIG welded joint.

Fillet brazed frames are beautiful. I owned one of the original Santana Noventas and my wife stll complains that we sold it.

-Dennis

I own a fillet brazed Bilenky Signature - beautiful bike, I own a new Co-Motion, beautiful bike. Not all TIG frames are the same. I have stayed away from Alum. bikes to date because of their not very pretty welded lines which probably have nothing to do with strength. Alum can be pretty - just look at Klein singles. At some point I will probably buy a lugged tandem, because that is just what I like in the look of bikes.

Can you provide a source for this use of fillets and/or steer me towards someone who's using fillets in this manner? I only ask because this is the first time I've heard of this suggested use of a fillet vs. a lugged or TIG welded joint.

Look at the lighter solo frames and a fillet is often used on the headstock to down tube. Then look at the full Downhill frames and this spot is invariably where the Fillet is used. Just looked at my bikes and no fillets on them but my lightweight frame (2.9 lbs for the bare frame), that is out on loan, has the fillet. Just realised that I am talking Mountain bikes, where extra strength is required so may not be what many here ride. Manufactures that use them are Giant, Yeti and quite a few of the top end frame manufacturers.

Many years ago I was involved in Space frame manufacture of Motorised vehicles, and we did not have double butted or varying thickness tubes in those days. It was common to use the lightest tube possible for a use, and to strengthen the area around the weld with fillets. Not on every joint, but where we had problems with stress breakage.

Look at the lighter solo frames and a fillet is often used on the headstock to down tube. Then look at the full Downhill frames and this spot is invariably where the Fillet is used. Just looked at my bikes and no fillets on them but my lightweight frame (2.9 lbs for the bare frame), that is out on loan, has the fillet. Just realised that I am talking Mountain bikes, where extra strength is required so may not be what many here ride. Manufactures that use them are Giant, Yeti and quite a few of the top end frame manufacturers.

Fillets or gussets?

Just realised that I am talking Mountain bikes...

Funny, I just realized you're talking about gussets...

This is a steel TIG welded head tube joint
http://www.antbikemike.com/images/Building/step11big.jpg

This is a steel fillet-brazed head tube joint
http://www.adbikes.us/images/s3c_htside_detail.jpg

This is an aluminum TIG-welded, heavily gusseted MTB head tube joint...
http://bilder.giant-community.de/gusset2.jpg

Some folks tend to use the word 'fillet' and 'gusset' interchangeably.
However, 'fillet brazing' is not to be confused with the words fillet/gusset.
A gusset is defined as 'a brace to reinforce corner/angle.' Fillet is defined as 'to bind with a band/molding.'

Some folks tend to use the word 'fillet' and 'gusset' interchangeably.

First time I've ever heard that too....

Real nice!
Looks like your favorite color is red! Love the yellow accents. Unusual!

Beauty is in the eye of the beholder.

I visited framebuilder Mark Nobilette the other day. His lugged frames and his fillet brazed work were all items of artistry and beauty. I was looking at some of his works-in-progress and was blown away by the artwork.

Me, I've used JB Weld to put bike parts together.

RFM

I'm kind of a sentimental guy that admits to 'bonding' (no pun intended) with inanimate things. Somehow a fillet brazed frame seems to exhibit more 'soul' to me than an industrial weld.

Fillet brazed frames; gotta love 'em. :)

heres a couple pics of some of my tandem joints...enjoy!

DW

http://i47.photobucket.com/albums/f183/Walkercycles/IM000654.jpg
http://i47.photobucket.com/albums/f183/Walkercycles/IM000651.jpg
http://i47.photobucket.com/albums/f183/Walkercycles/IM000650.jpg
Beautiful work Don! Can you tell me more about the tube sections? Is that a "shaped" downtube, and how did you ever fabricate that section where TT and LT come together at the HT? It reminds me of the huge aluminum tubes used on my Softride 650 TT, except your joints look about 10x better.

Love the crime scene/bloody paint job on that track tandem frameset . . . very original . . . and that bent rear seat tube brings back memories!
Back mid-70s we designed a road tandem and had it built by Matt Assenmacher in Michigan. It had a bent rear seat tube to shorten the wheelbase. Also had toeclip overlap and a very tight stoker compartment (stoker is 4'10 3/4") with a 60 1/4" wheelbase and weighed a then incredible 34 pounds.

Where is Assenmacher?
He owns a couple bike shops in the Flint, MI area and has pretty well hung up his torch.
We had the 3rd tandem he ever built when he opened his small shop in Swartz Creek, MI. He understudied at Bob Jackson in England for about a year before opening his frame shop in the US.
We had an oval boob tube on that tandem. After ours was built, one of his signatures on a tandem was a rectangular boob tube.
For our bent rear seattube, he had to hand bend 3 tubes before he got it right. Swore he'd never do that again. We utitlized Reynolds 531 DB single bike racing tubing with twin laterals with re-inforcing bridges. It was a male/ladyback design. Put 64,000 miles on that machine. This really got us hooked on custom tandems.
Pedal on TWOgethert!
Rudy and Kay/zonatandem

Integrating tubes is labor intensive, but sometimes necessary for proper fit/strength/looks.
On our current ariZona c/f tandem we had a slightly different approach, but again very laborious; integrated lateral/downtube
Did as much c/f as possible: frame/windowed lugs/adjustable stoker stem/stoker handrests and later even added a c/f rear rack. That tandem is now closing in on the 10,000 mile mark.
You're bound to pop some eyebals with your 'crime scene' tandem at the expo!

Funny, I just realized you're talking about gussets...

This is a steel TIG welded head tube joint
http://www.antbikemike.com/images/Building/step11big.jpg

This is a steel fillet-brazed head tube joint
http://www.adbikes.us/images/s3c_htside_detail.jpg

This is an aluminum TIG-welded, heavily gusseted MTB head tube joint...
http://bilder.giant-community.de/gusset2.jpg
Mark,
I couldn't help noticing the jigiture jig behide the tig welded frame. Is it large enough for a tandem frame and what do you think of it? I'm looking around for my first frame jig and learning just how expensive they can be. Not real practical for a hobby so far.

Sure, the Downtube is a Columbus BMX "D" Shape. Its straight guage and I think 1mm. Adds to the stiffness that is needed for track.
The top/head/lat joint...wow, that was a chore. I fabricated a gusset for that area. Let me dig for pics.
Thanks for the compliment on the clean joints.
DW

http://i47.photobucket.com/albums/f183/Walkercycles/Tandem/1b16dc2c.jpg
http://i47.photobucket.com/albums/f183/Walkercycles/Tandem/7eaacf21.jpg
http://i47.photobucket.com/albums/f183/Walkercycles/Tandem/5dab9c9b.jpg
The gusset is very innovative and the way it blends the two tubes is strikeing. This is what "custom" is all about! Congratulations on a remarkable piece of work. See you at the show.

rlong