How to build a lugged steel frame, with pics

[big john]

Is it wrong that I'm almost as equally impressed that you're making your own cages as I am about the frame itself?

I don't know, I was pretty impressed by the rack he made for another bike.

[Fat Boy]

Here's a couple questions.

1. Any reason for using paste flux instead of the in-gas flux?
2. You seem to be using brass instead of silver solder, any reason?
3. Your seat stay work is quite a bit more involved then using caps or plugs, is this just for the visual or is there a structural reason?
4. How did you arrive at your choice of tubeset?

And, by the way, beautiful work.

[Cassave]

Here's a couple questions.

1. Any reason for using paste flux instead of the in-gas flux?
2. You seem to be using brass instead of silver solder, any reason?
3. Your seat stay work is quite a bit more involved then using caps or plugs, is this just for the visual or is there a structural reason?
4. How did you arrive at your choice of tubeset?

And, by the way, beautiful work.

To answer your questions;

1. I don't own a gas-flux unit and can't justify buying one.
2. No, it's silver, 56% AWS Bag7.
3. Visual, it's tougher to do than caps but it stiff and very light.
4. It's cheap, standard sized (I already had lugs I wanted to use) and available.

And thanks.

[Cassave]

Is it wrong that I'm almost as equally impressed that you're making your own cages as I am about the frame itself?

Don't be impressed.
The cages are easy to build, frames are a bit more involved.

[Mo'Phat]

: popcorn :

Fascinating! Only thing I ever built was a Team Associated RC-10 back in middle school. That ended badly.


Which is why I will never trust myself on a homemade bike.

[chimivee]

Only thing I ever built was a Team Associated RC-10 back in middle school. That ended badly.

I built two of those back in middle school. But I think mine ended quite nicely.

[voltman]

: popcorn :

Fascinating! Only thing I ever built was a Team Associated RC-10 back in middle school. That ended badly.


Which is why I will never trust myself on a homemade bike.

Which part ended badly, the build or the car smacking the side of the cafeteria?

[voltman]

I built two of those back in middle school. But I think mine ended quite nicely.

We should build some more.

[Fat Boy]

So I think lugged steel frames are great, but for the money it takes to get one custom made, I think one of these days I'll just have to build one.

I have the Paterek book. It has a lot of good info. Henry James seems like a good resource. It'll be 100 years before I actually get to that point, but if I could build something like the piece of art you've produced I would turn backflips.

Anyway, what geometry did you choose, and how did you go about deciding on that geometry? I've built car frames, and there are very specific reasons and justifications for building things in a certain way. There seems to be very little information on bicycle vehicle dynamics and the geometries seem to be chosen in a very touchy-feely way. I think that some of the motorcycle information would transfer, but I don't really know how much is applicable.

If you've build scores of frames, I'm sure you have your pet theories, but I'm very curious how you approach the problem.

[Cassave]

So I think lugged steel frames are great, but for the money it takes to get one custom made, I think one of these days I'll just have to build one.

I have the Paterek book. It has a lot of good info. Henry James seems like a good resource. It'll be 100 years before I actually get to that point, but if I could build something like the piece of art you've produced I would turn backflips.

Anyway, what geometry did you choose, and how did you go about deciding on that geometry? I've built car frames, and there are very specific reasons and justifications for building things in a certain way. There seems to be very little information on bicycle vehicle dynamics and the geometries seem to be chosen in a very touchy-feely way. I think that some of the motorcycle information would transfer, but I don't really know how much is applicable.

If you've build scores of frames, I'm sure you have your pet theories, but I'm very curious how you approach the problem.

Regarding the frame dimensions and geometry;

Dimensions fall into two groups; sizes and dimensions needed to accomodate the components (wheels, brake and tire clearances etc.) and the lengths and angles related to rider size (toptube and seat tube etc.)
Steering and stabilty is most affected by the trail dimension established by steerer angle and fork rake.
For a lightly loaded road bike I prefer about 58 to 60 mm of trail. That results in a quick steering feel at low speed and very high stability. For heavily loaded (touring, porteur) bikes much less trail is used to
produce lighter steering under the load. A well designed touring bike handles better loaded than unloaded.
Bottom bracket drop has an effect on the perceived stability of the bike, specially when pedaling out of the saddle. 70mm is pretty standard for "sport" road frames. Tourers usually have more drop.

I have built a fair number of frames and several for myself. Over the years I've settled on a design with short front center (BB to front axle), a slightly long chainstay and as I said, about 60mm of trail.
This bike is 58 cm C to T, 57 cm TT length, parallel 73 degree head and seat tubes and 42.5 cm chainstays. 42mm of fork rake gives me just less than 60mm of trail. It sits on a 101 cm wheelbase.

[Cassave]

Just about done with this thing.......
I added the shifter cable bosses and a set of rack bosses.


Only the studs are stainless, the reinforcement is carbon steel and will be painted.


Another view...


The stainless rack bosses. One boss is extended to double as a chain hanger peg.


Seen here installed on the fixturing to keep them in perfect alignment when I
braze them.


Brazing the uppers onto the seat stays.



There, seen in-place and polished.


All the brazing is done. Next thing is some additional polishing on the stainless
bits, clean it and get it ready for primer and paint.

Tonight I'll make a simple bending guide and start the water bottle cages and
with any luck I'll shoot the primer on the frame on the weekend.
Still gotta figure out a color scheme....

[Cassave]

Bottle cages.............

I made three, two for this new frame and one to try out on my commuter.
Made of 3/32" diameter 302 stainless rod. They weigh what seems like nothing and
look pretty nice.


The cages brazed......


Adding the mounting tabs....


One finished and polished, mounted on my commuter.
I like it!

[roadfix]

The bottle cages look just like the Nittos, except better, since you made them!

[Cassave]

The bottle cages look just like the Nittos, except better, since you made them!

They're a blatant ripoff of the Nittos.
I don't know about better, but they were certainly a lot cheaper

[MTBMaven]

Stunning. I can't wait to see what you cook up for the paint scheme.

[Cassave]

Ok, almost done;

Finally got it painted! But first, the last mechanical operations;


Facing the BB shell to 68mm.


Reaming the headtube for the headset cup and upper race.


Primered with a 2 part epoxy primer by PPG. The masked areas
are either stainless of already painted white.


Now in color and de-masked. Lug edges need smoothing then
ready for clear coat....


Now decalled and ready for clearcoat.....


Now spayed with the Limco acrylic urethane clearcoat.


bottom bracket area.....

So next thing is to be patient while the clear hardens for a few days
then I'll install the headset and bottom bracket, in the meantime
I have wheels to build.

[Fat Boy]

I'd comment here, but I'm pretty much speechless.

[roadfix]

Beautiful work! Nice color too......that blue reminds me of my old Univega Gran Premio.

[big john]

Looking forward to seeing it on the road.

[Cassave]

Looking forward to seeing it on the road.

With any luck that'll be the short ride on Sunday.

[Tiffanie]

What a fantastic thread. Beautiful pics, beautiful bike! :thumbsup:

[Indolent58]

Wow. Excellent work.

[Pepper Grinder]

That is a superb paint and lug job. The stainless lugs are sweet! What kind of bling-blingin' wheelset do you plan on throwing on that thing?

Needs a serious headbadge. I can't wait to see pics of this build completed.

Wow. If that was my bicycle, I would be so sad if I dinged it. Ever.

[Cassave]

That is a superb paint and lug job. The stainless lugs are sweet! What kind of bling-blingin' wheelset do you plan on throwing on that thing?

Needs a serious headbadge. I can't wait to see pics of this build completed.

Wow. If that was my bicycle, I would be so sad if I dinged it. Ever.

Thanks.

Wheels;
I'm building them this evening. Nothing special, Record hubset, Mavic Opens, cross 3 using DT spokes.
They'll last forever.

[Seamus]

Wow. Just wow. And of course you build your own wheels too.

Did you work at Colnago or Bianchi in a previous life?

Jim