bikesrbest 

Zunow Z-1

bikesrbest 

Fitz

bikesrbest 

Confente (not mine)

bikesrbest 

Raleigh Pro

bikesrbest 

Hetchins ('65)

Dylansbob 

CNC Special

merziac

@bikesrbest

Hi Ray, we need to see the Merz's, especially the the clearcoated one.

bulgie 

Why, what's wrong with it? Looks pretty swell to me.

Anyone seen one with the paint off, so see how those shallow holes in the top eye are made?

They're probably machined in to a solid-steel plug, just a slight plunge cut with a center-cutting endmill. Or investment-cast to look machined. But I like to imagine the stay is the kind that's hollow right out to the end and capped with a thin piece of tubing laid into a coped or shallow-angled miter of the stay itself. That type of stay top is more work but definitely lighter, so I very much prefer it, even though the weight difference is something like an ounce. It's the principle of the thing! Solid plugs feel a bit like a cop-out to me or at least a shortcut. (I have used lots of solid plugs too, so I'm not saying that makes anyone a bad person!)

For this Grandis to be a hollow/capped type, the holes could be machined into a relatively thick cap, or the cap could have the depressions stamped-in, the way early Trek bikes used.

You can almost always tell which way a stay is capped when you see it without paint or plating, and sometimes even through the paint, but this Grandis doesn't give visual proof either way. Probably solid though.

Still a really nice looking cluster! Classic, but with a unique flair

Mark B

steelbikeguy

hey Mark, a trivia question for you... was Raleigh's SBDU group the only to use an oversize cap on the seatstay? When I got my SBDU frame, I wasn't familiar with it, and the appearance was a bit annoying. I've since learned to appreciate it as a sign or marker of the quality that SBDU put into their frames. I assume that having the cap extend a bit beyond the tube allows a fillet to form on both the ID and OD of the tube, permitting a visual inspection to verify that a fillet is formed around the entire OD.

I seem to recall discussions of some seatstay caps on other bikes developing cracks.

Any observations or comments on the use of oversize caps and whether it is warranted??

Steve in Peoria
(and as an engineer, I expect all answers to start with "It depends....")

bulgie 

No, this was used decades earlier, most often in France. Bernard Carre (and brands he built for such as Lejeune) being the most common of the ones I've seen. Jack taylor and and CNC also come to mind.

Yes, astute observation. But a stay cap that's brazed properly, with an inside fillet all around, can safely be trimmed to flush with the stay, as long as the cap-to-stay braze doesn't get re-melted later when the stay is brazed to the seat cluster.

I've seen some builders use a higher-melting-point filler rod to put the caps on, specifically to avoid remelting. I've seen caps copper-brazed on (much higher temperature than brass), but only on cheapish frames because copper brazing is so damn hot. On a quality lightweight, you're more likely to see brass used to put the cap on, and silver to attach stay to lug. But the most common scenario is brass for both, with a little re-melting tolerated, so you'll see a gap there sometimes — or even cracks.

I like silver for attaching seatstays to the side of the lug, but the typical "runny" silver (high silver content) used for lug joints is not an ideal choice, unless some sort of mitering is done to give more area of contact. As you know, a cylinder contacts the side of another cylinder at a mathematical point, contact area = zero, and silver isn't very strong in that kind of joint. I like to make a divot in the lug to match the stay, but you can also divot the stay to fit the lug. For the latter, the limiting factor is going through the thin tube wall of the stay, which wouldn't be fatal but I think it's suboptimal. The lug has more "meat" for mitering and it's an easy miter to make, a few strokes with a round file the same diameter as the stay. You can also use a silver that's optimized for making a fillet, like Fillet Pro from Cycle Design — with ot without a divot.

But honestly "brass for both" is usually fine, for a careful brazer. With a good inside fillet, even a little remelting of the cap braze is OK. This is why most bikes made this way don't end up cracking.

Mark B

El Chaba

Here is an assortment:
Alex Singer…

Denti Master Pro

“ Motobecane” Team Champion

DeRosa Professional ca 1991

Gios Compact Pro

Meral ( this particular bike is borderline magical)

Andy Antipas 

1990 Atala

1973 Colnago Super

1979 Gios Super Record

1984 Gitane Team Pro

1963 Masi Special

1977 Davidson Custom

1979 De Rosa

circa 1982 Doug Fattic

1969 Urago

Celloplus 

My custom Tommasini

fabiofarelli

Ago15

....

steelbikeguy

until you can post photos, how about some hints to build the anticipation??

Steve in Peoria

merziac

Really, pretty sure we'll be the judge of that.

That being said, welcome aboard, glad you found us.

You can post pics to the album on your homepage and then they may get moved her.

And as said above, talk them up so we get an idea, 5 posts x 2 days will get you to posting pics too.

steelbikeguy

wait, is "heavy" the clue?

is it a Schwinn Continental?

Steve in Peoria

Ago15

....

steelbikeguy

well, with that clue, I have to guess Columbine...



edit: almost forgot this article, which shows a Columbine seat cluster....



Steve in Peoria

El Chaba

Okay, here is another Peugeot from the Prestige shop (but not a ex team frame)…and this one is a couple years later from the roughly 1.5 year time frame that they were using long point lugs with windows. By this time, the centerpulls were gone, the entire rear triangle was chromed, but the seat cluster treatment remained the same. Incidentally, this seat cluster treatment was the design of the shop foreman, Raoul Jean D’Heure.

bulgie 

Pic assist:


Very nice!!
Please direct all questions to Ago15

Mark B

bulgie 

'80s Davidson funnybike (I built this one), steel with composite fairing:

Note the exit for the rear brake cable below the monostay. It runs inside the fairing. It's set up here for track pursuit, but for road TT it used Modolo Kronos brakes.

'70s Graftek, I peviously owned but sold:


Keith Lippy (not mine):


Faliberto Maasi [not a typo, double-a in Maasi] (not mine):


'70s Art Stump (not mine):


Toei (god I wish it were mine):


Schulz Funiculo (not mine):



Mark B

John E

1962 Carlton Franco-Suisse, my only "Brit bike," all stripped down and ready to rebuild.

Repainted Capo Sieger frame, serial number within 30 of my other Sieger. Capo seat lug is ornate; clamp is kind of klunky, but clever design, just a steel oval bent in half around a dowel




A bare Project KOM frame.

RustyJames 

Funny this thread came up recently. I showed a friend my recently acquired Diamond Back Mean Streak and he said “I love that seat lug!”




Kinda fancy for a mountain bike.