sillverchevy

Hi,
I received today a 1985 Lotus Supreme I recently purchased. After some complications with shipping (I am hopefully working out with seller), I assembled the bike. On the down tube and bottom bracket lug/weld, there appears this bulge. Is this damage to the frame, or is this the factory junction between downtube and bottom bracket lug. Hope the pic is somewhat clear.
Ron

Chris_in_Miami

That's a pretty significant bulge, but I'm not sure it could be caused by some kind of impact without causing noticeable damage elsewhere on the frame. What does the top of the BB shell look like?

I'd pull the BB apart and check if the down tube ends at the line along the bulge. If the tube extends past it to the inside of the BB shell, I'd be inclined to believe it was made that way.

sillverchevy

The rest of the frame appears straight. This bulge is at bottom of down tube. When I run my fingers around the tube to the inside portion of where the downtube meets bottom bracket/lug, again I feel a bulge. This leads me to believe the bulge is the actual downtube inside the lug/bottom bracket. Is this normal. The bike is columbus sl/slx??, and built in Italy, designed by Cinelli, from what I've read.

Chris_in_Miami

I'll have to defer to someone with firsthand knowledge of that frame or lug type, it sounds atypical and I've never seen a bulge like that before.

For the sake of clarity, when you say "the inside portion where the downtube meets the bottom bracket," are you referring to the top side of the exterior of that joint, or the inside of the joint as accessed through the disassembled bottom bracket?

sillverchevy

That would be the top side of the exterior of that joint. I did not take apart the bottom bracket.
Ron. Also, the paint around that bulge is fine, no crazing or cracking/rust. i don't know, I'm thinking it is the joining of the down tube within the lug. Any experts ever seen this before, and would this be a major deciding factor in keeping the bike.
Ron

JunkYardBike

I'm not an expert, but I wouldn't be too concerned about it (does that make sense?). In my small fleet, I've got two frames with the same bulge. A few of my other "higher end" frames have cutouts at that point - maybe for the very purpose of eliminating the same type of bulge. There are some C&V regulars with framebuilding experience who might visit this thread, but you might also want to post it in the Framebuilding forum where someone might be able to explain it.

unworthy1

I've seen similar on many production frames, it always looked like sloppy craftsmanship to me, but never saw any fail there so maybe it's more cosmetic than a serious flaw. 'Course I didn't keep those frames around for very long, either

sillverchevy

Thanks,
I guess if its sloppy work its one thing. This frame was supposedly one of their top two frames, Cinelli designed and Italian built. I would have thought more care would be taken with these frames.

JunkYardBike

There's plenty of sloppiness to be found on high end Italian frames. The Centurion Cinelli Equipe I have has some rough filing work and irregular lug cuts. It's a nice frame to be sure, but nothing compared to the Greg Diamond I have, which came from a low production one-man shop.

After seeing your BB shell, and considering that my Centurion Cinelli has lots of Cinelli frame parts and engraved logos, I reread the best information I could find on the Lotus Supreme (courtesy of T-Mar) and he mentions this:

"Tsunoda did make a Columbus tubed Supreme."

So, it's possible it's a Japanese made model. I thought the Campy headset would be an indication that it was formerly Campy equipped, suggesting one of the Cinelli built Lotus frames, but maybe not. Maybe it was a later replacement and the DA EX is original, or maybe one of the Japanese built Columbus tubed models was equipped with Campagnolo.

At any rate, it's still a nice frame with nice components. BTW, I'd guess the frame was built with SL, and likely an SL/SP mix at that size. Probably not SLX.

redxj

I have the same color Lotus Supreme sitting here in the basement shop. The bike would have came with a full Super Record group on it stock. When I bought it I got a zerox copy of the original catalog scan for it (which I can't currently find). The frame is either Columbus SL or SP. I believe SP was used on the 58cm and bigger sizes.

JunkYardBike

If you can find it post it up! The only Lotus catalog scans online that I can find are here: https://www.wooljersey.com/gallery/v/...lotus/catalog/

sillverchevy

Redxj, i could find only one other supreme on the net, and it too came with full dura ace ex. Strange....This frame is a 57 cm, so I believe its SL as well. Junkyardbike, the dropouts are throwing me for a loop. Colmbus tube, rear drops are vertical with mano stamped in (huh). Front drops I can make out ange tr (tange I presume) Any idea of the rear drops?

kirke

Here is a circa 1981 Lotus catalog, featuring the Supreme model. It shows that it was second from top-of-the-line, made from Tange tubing, and had a full Dura Ace EC gruppo. However, I have seen several Columbus SL Lotus frames, even mid-range touring models made from Columbus.

https://www.wooljersey.com/gallery/v/...lotus/catalog/

miamijim

100% normal. Its supposed to be like that. Its a low end feature not a 'sloppiness' feature.

JunkYardBike

Shimano? Well, looks like it's a Tsunoda built frame, as confirmed by T-Mar in your other thread.

It was a high-end frame in the Lotus line-up, but it does look like they cut some corners on the bottom bracket.