I just picked up this De Rosa frame, probably late 80's, Columbus SL tubing, 130mm dropouts and no serial number.

I did some serious web searching for sights like those for listing Colnago and Masi time lines but no GOOD info on De Rosas.

The most that I could come up with was that a lot of De Rosa frames were custom built to the owner's specs and they could have had features from different eras regardless of the build date.

eBay photos:







This was a "bucket list" bike. I would prefer a mid 70's bike but this was an impulse retirement gift to myself.

verktyg

There is a very good graphic De Rosa time line on the net. Google "classic de rosa guide" and you will find.

You write "a lot of De Rosa frames were custom built to the owner's specs and they could have had features from different eras regardless of the build date"
This is true in relation to the time lines for Colnago and Masi - also. And a lot of other makers. A time line is a probable period and clue - not a truth.

[MENTION=61614]verktyg[/MENTION] - Congrats! I too have one on my bucket list. Just not ready to start looking. Great find!

That's right about variation of details for different customers...and also for different importers/markets...Considering everything, I would guess the frame as a little earlier...early 1980's based on the bottom bracket/lugs and SL tubing vs. SLX. This frame had to be re-spaced to 130 mm...

At least you got to take it home. The dropping off at the door, getting a goodnight kiss, turning around and having to leave gets old after a while.

the fork messes with my best guess as to build year. DeRosa was small enough that batches of parts were tried, so a set of frames may share details never to be seen again.

Looks a bit on the larger size for you...
should be a nice bike when built... You know it Should have Campagnolo...
What size tire can the frame set accept?

Concur. My research material puts this one somewhere 81-83. Also observe the rear brake cable routing rings on the top tube. Same as on my circa 1980 De Rosa - with Microfusione lugs.
Collected material on frames/forks with the sloping crown design points to 1981-83.

OK - I will write it again... Picture google "classic de rosa guide" (with citation marks) and you will get a very good graphic time line made by Andrea Bonfanti. A lot of questions is answered right there.

I agree with this dating. SL with FD mount would be this time frame. Unlike other builders once DeRosa got SLX tubes they didn't build anything less than that.

https://www.classicderosa.com/wp-cont...c729c246_k.jpg

The problem is it stops at 1985 and provides essentially no distinguishing information for 1980-1985.

I think that I rule out very early 1980s based on the post-Portracatena dropouts and presence of a front derailleur hanger. I'd say mid-1980s

I agree. based on the graphic guide referenced, tall signs ( BB, Seat stay caps, Fork crown, head badge decal) all point to around 1979-1985, where the guide stops.

De Rosa used De Rosa dropouts through 1979, at least, so lack of Portacatena means nothing.

Concur again. Here is my circa 1980:




I stand by my 1981-83 estimation based on the top tube cable tunnels. Later they had a different thinner design.

Spot on.

81-83 sounds right to me, but I could buy 1984. I'm no DeRosa expert, but several people I trained with had these during this time, and I remember them. DeRosa was ahead of the trends on both under BB cable routing and front derailleur mounting. The first braze on front derailleur I ever saw was on a friend's DeRosa circa 1982.

Edit: Actually - the first braze on FD I saw was on a Rigi, circa 1980, but those are a special case.

And I have got a circa 1977 Pogliaghi with under the BB routing.

Yes it does (stop at 85 etc.). Thats where collecting pictures/material over a long period of time comes in. Using it to interpolate data to narrow things down to a probable period (still not claiming truth - always using "circa") The part I call "my research material". As I have shown here on BF I am willing to share my findings (Bianchi Proto thread, Merckx Corsa Extra MAX and MX Leader time line). I do this to share - and/but when there are good material already out there I do like people to do their own research within the already given material. More eyes and minds going thru material often takes us further than when just dishing out what you know or believe you know.

The finest gathering of material I have seen in our hobby is Bob Hoveys work on Masi - both US and Italian.

I really thought this thread was going to be about this forum's lust for the bicycle form itself

I am a married man. Dating is a thing of the past. I do however keep a couple of Rosa: s on the side to cuddle with. My wife does not mind... ;-)