gugie 

It used to be a generator wire, but then it got painted over.

It happens.

gugie 

whatwolf

Another guess: Some sort of attachment point for a front wheel stabilizer

nlerner

I could certainly imagine that the shifter bosses were added later and perhaps the water bottle braze ons. I was thinking that the cable guides, particularly the gear cable guides on the drive side, are a unique feature.

lostarchitect 

My '64 JRJ takes a 27.0 post.

noglider 

Six pounds even is quite light for a complete frameset of that size. I hope it rides as well as it looks good. Maybe the stalactite is something for hanging a race number.

MauriceMoss

I saw this frame in the for sale section and thought I might throw my hat into the ring of guesses.

The features here aren’t unique enough to get a positive ID, so I’m just making a semi-educated guess.
On seeing the serial number, I thought that this could be a Witcomb (a UK built rather than a CT one). Serial numbers on Witcomb frames generally have the year as the last two digits and can be 6 or 7 digits long overall.

Witcomb were a bespoke shop that employed a number of builders over the decades they were located in Tanner’s Hill, Deptford, so their frames show a wide range of features. This makes it hard to pin things down.


Here are some pictures that will hopefully support the case for it being a Witcomb:


Serial/Frame Numbers:

Numbers were generally stamped across the bottom bracket. Also, I have yet to see a Witcomb number that was stamped in a perfectly straight line (like you’d see on a lot of mass produced Japanese frames, for example).

The numbering system would appear to be [sequential frame][yy] as numbers from the 60s seem to be mostly 6 digit and then growing to 7 digits by the early-mid 70s. However, this video bit about Witcomb:


has a scene (around 1:30) where Barry points to their ledger where you can see frame numbers from the last week of July 1973 that range from 1010673 to 1017073. Seems like a pretty wide range for 10 frames built in one week.

Anyways, here are some examples:

650569


650869?



954472




1027973



1122475





The ‘stalactite’ bit:






Use of Nervex lugs:

Most Nervex Pro built Witcombs I’ve seen didn’t have the ‘rib’ filed/trimmed but there are a few that did.





The circular cable guide use:




Fastback stays, sloping fork crowns, top tube cable guides, stay ends:




This one was allegedly made by Bill Philbrook:

nlerner

Thanks, @MauriceMoss for that helpful info. This frame is on its way to @gugie, who will do some modding for its new owner, @bwilli88. The result will be a lightweight 650b racer.

hokiefyd 

It reminds me if the ice indicator post on the front of aircraft. As you fly through visible moisture at temperatures approaching freezing, that little post will build up with ice, alerting you to the potential for ice on your control surfaces.

You'd never want to lay your bike down on a patch of black ice, right? This is a vintage, low-tech, way of being able to predict black ice. As you ride your winter commute, you periodically reach down and feel that ice indicator post -- if it's clean, you're good to go! You just have to ride fast enough...

No?

conspiratemus1

Sorry. I see that it was a zombie thread. But it's still funny. Modular teeth.

Salamandrine 

That sounds like the correct theory to me as well. I'd guess that frame is pinned and brazed, and they used another pin for a stop.

6 lbs total for the frameset is on the light side for a 531 db frame. They can vary a lot as there wasn't really a standard gauge AFAIK. The hand filed lugs are a rather obvious indicator of a top end hand built frame.

I'd wager some of the braze ons are original. It's not like they didn't know how to do them in the 70s, it's just that they were out of fashion.

bwilli88 

So maybe it is a W

itcomb, nice to know.
Looking forward to building this, A bit of Gugieification and a couple of custom racks and this will probably be my new main bike for Cambodia.

Gravity Aided

I'm pretty sure about the stop for clamp mounted downtube shifters. I have one on my Falcon San Remo, and Campy clamp on downtube shifters fit over that like a glove.

nlerner

It just seems a bit odd that the peg is much more crudely brazed than anything else on the frame.

due ruote 

OK, how’s this - the pin was the original stop, beautifully brazed by Whitcomb or whomever. At some point the bosses were added, and when they did that they chopped the pin off. Then someone walked in and said bad move, so they hastily stuck it back on.

noobinsf 

Maybe an apprentice got this task?

jdawginsc 

Wild guess....a knob to keep the fender in front from moving side to side?

Lascauxcaveman 

Cigar poker, obviously. But a terrible location for it. Typically British.

Spaghetti Legs 

I think it’s a place to stick the cork if you have to make a gear change while drinking from your wine bottle.

juvela

-----

Once again, @MauriceMoss knocks an inquiry clean out the ballpark!

And with outstanding documentation as well, como per normale.

Found it interesting to note that Witcomb apparently could not decide if their serials should be read with stays toward the top or with head toward the top.

---

Initially doubted idea that item could be for no-slide purpose as it seemed unnecessarily long for this.

Then it finally dawned on me dull "braine" that it is made to work on the shift lever assembly's pinch bolt rather than on the band itself like most others.

One can only wonder why the person who added all of the post-manufacture braze-on bits left it in place...

The "diver's helmet" housing stop on the downtube looks positively huge compared with the Campag Nr. 621 they fitted to the chainstay.

---

There was a shop in my area which was a Witcomb stockist from the mid-seventies through the early eighties.

So I got to view a number of new Witcomb framsets in their showroom over time.

There was one oddball piece which sat for years.

The frame itself was not odd, it was the finish.

It had evidently been done in the early eighties as part of the aero craze and was given a "golf ball" paint finish with thousands of small dimples.

Do not know how this was achieved, have never seen another.

Does anyone recall seeing a Witcomb with this golf ball finish?

-----

shmuelyosef

The clamp-on would allow adjustability down low (out of sight) and the fixed peg (now broken) would add convenience?