Frame tubing question

[retrobloke]

Does anyone know of a frame manufacturer that produced frames with a downtube that looks like a rifle barrel flipped inside out, so it looks like spiral ribs twisted around the outside of the tube.

 

[Tad]

In a word, no.

Damascus twist frame tubes, they would look amazing in just clear laquer.

 

[Anthony]

Does anyone know of a frame manufacturer that produced frames with a downtube that looks like a rifle barrel flipped inside out, so it looks like spiral ribs twisted around the outside of the tube.

Does it look like this?

 

[barry2017]

Byercycles also had a 26" wheeled touring bike called the Spiral. I think it was made by Tange, and sold by several smaller builders.
Not special, but good quality; it was nice.

 

[dyna-ti]

This forum will never cease to suprise me,a really obscure part weird in it's design
somebody has one or three

 

[retrobloke]

Thank you all for replies.

Anthony yup thats the one identical tubing even finish and forks look the same the only difference is it's the down tube not top tube, thanks again for reply. What make is the one in the photo, and which frame material.

 

[Anthony]

Thank you all for replies.
Anthony yup thats the one identical tubing even finish and forks look the same the only difference is it's the down tube not top tube, thanks again for reply. What make is the one in the photo, and which frame material.

The bike in the photo is a Merlin that is currently for sale on eBay. For a long time, Merlin Cycles used to offer a steel frame that they called a TDB (for Tange Doubled-butted) and their blurb said it was made with 'the latest Tange Spiral-butted tubeset', so although I've never seen one I presume the bike in the photo is one of those TDBs. It has a spiral-butted seat tube as well. It looks as though the spiral is an externally-applied butting, which must strengthen the tube, perhaps sufficiently to enable a thinner-gauge tube to be used.

The TDB used to sell for £135, whereas the Merlin WCS, which was made out of the highest grade of Tange/Ritchey tubing, was £199. As ever, these were very good value frames, always highly-praised. I imagine that the TDB wasn't heat-treated, but would have been at a level just below Prestige. i.e., at or slightly above the quality level of a generic 4130 db frame like a Cinder Cone or an Eldridge Grade.

I don't know of any other manufacturers that used the spiral-butted tubeset, but Tange dominated the market in those days, so if they were making it it must have been fairly widely used, I should imagine.

 

[Ladis]

Yes, I remember "Cecker Pig" had such a frame with spiral tubes...The man from the bikeshop said, it makes the bikes stronger or even more rigid....

 

[Old Ned]

One of the Columbus tubing sets (SLX?) is spirally butted internally. Perhaps they have a patent on it so other tubing manufacturers have to put theirs externally?

 

[IbocProSX]

Amazing stuff, never seen it before. But I do remember Koga Miyata had triple butted CroMo tubes advertised with INternal spiral butting.

The blurb read something like "HardLite FM3" tubing and had nice artist renderings showing off the gun-barrel like spiral patterns as cutaway drawings.

Enjoy!!