Vintage Dunelt lightweight (1959?)
- Thread starter Jonas
- Start date
More Dunelt 10 speed info just discovered. Hope I am not boring anyone to death. I noticed that the bottom bracket sleeve (on my bike and on the eBay frame) has an oval within it stamped RGF. Here is a cut and paste of another post I discovered explaining it.
[Dave Moulton
03-25-06, 06:39 AM
I’m pretty sure RGF bottom bracket shells were made in France. I used them on most of the frames I built in England through the 1970s, and bought them from Ron Kitching who imported them along with the Prugnat lugs. These BB shells were “Bulge Formed” which is an interesting process and I will explain for the benefit of those who have not heard of this.
A steel tube with the diameter and wall thickness of a bottom bracket shell is fed into a special machine. A mold clamps around the tube that has internal sockets that form the down tube, seat tube, and chainstay sockets. The ends of the tube are sealed and hydraulic oil is pumped inside. The pressure causes the steel to blow into the sockets like a bubble.
The mold opens, the tube slides sideways to clear the mold and a saw cuts it off. The machine repeats whole process automatically. In a separate process the sealed ends of the sockets are machined off making the finished sockets for the tubes. Finally the BB shell is faced and threaded.
I used these BB shells because they were the best available at that time. By the late 1970s investment cast bottom brackets, which are far superior, became available. I’m sure the bulge forming process is still being used for lower end bikes.]
[Dave Moulton
03-25-06, 06:39 AM
I’m pretty sure RGF bottom bracket shells were made in France. I used them on most of the frames I built in England through the 1970s, and bought them from Ron Kitching who imported them along with the Prugnat lugs. These BB shells were “Bulge Formed” which is an interesting process and I will explain for the benefit of those who have not heard of this.
A steel tube with the diameter and wall thickness of a bottom bracket shell is fed into a special machine. A mold clamps around the tube that has internal sockets that form the down tube, seat tube, and chainstay sockets. The ends of the tube are sealed and hydraulic oil is pumped inside. The pressure causes the steel to blow into the sockets like a bubble.
The mold opens, the tube slides sideways to clear the mold and a saw cuts it off. The machine repeats whole process automatically. In a separate process the sealed ends of the sockets are machined off making the finished sockets for the tubes. Finally the BB shell is faced and threaded.
I used these BB shells because they were the best available at that time. By the late 1970s investment cast bottom brackets, which are far superior, became available. I’m sure the bulge forming process is still being used for lower end bikes.]
As you can see, the bikes are identical, as is this frame for sale on ebay and one other bike in New York that is still new (amazing). So this is four that we know about. Three here in the US and yours over there. The rarest English 10 speeds in existence. Even the bike gurus, bike know it alls, and bike web masters around the globe can not dispute this. They are almost definitely not retro. Dunelt factory built bikes from before Tube Industries bought the name. Sooner or later we will find out from someone who was around at the time or involved with them exactly what the story is. I believe that Dunelt had just gotten into 10 speeds at the time and then after the big multi line buyout these were not carried over and just dropped. The left over bikes were just sold off later. And since they were built in England then I believe that this is where the info is hiding. More will turn up as time goes on.
Hi Jonas. After owning this bike for over 40 years I know when I see another one. Which has never happened till now. They are identical and the sticker I think you refer to is the dealer sticker. I also suspect that the rims on your bike were changed as was my rear rim. The originals bent very easily. Other then the rims and color scheme the bikes are identical.
