Velosaloon Blog
Velosaloon Blog
Chesini X-Uno / Precision 83 Aero Bottom Bracket Cable Guide
Chesini X-Uno / Precision 83 Aero Bottom Bracket Cable Guide
Many of the artisan vintage steel frames that we love and adore so much, especially those from the 1980s, had internally routed brake and gear cables. This design offered aerodynamic benefits as well as a sleek look. Chesini was one of the manufacturers who understood the art of internal cable routing to perfection. Both the prestigious X-Uno and the Precision 83 featured aero-guided cables.
While it does really look good, to enter the cables through the downtube - right where the levers are - and just let them exit - right where the derailleurs sit - this also brings up a difficulty of, how to run the cables along the bottom bracket?
For precise shifting, gear cables need to move smoothly with low friction and without a narrow radius. While one might think that the cable could simply run along the bottom bracket axle — the radius is large enough, and steel-on-steel friction is low enough — this would in fact be a fatal idea. As both parts move — especially the axle, which turns constantly when pedalling — they would soon start to abrade each other to the point where either the cable would tear or, even worse, the axle would break in half. Furthermore, it would not be possible to cover the bottom bracket in a dust sleeve, meaning you would lose protection against dirt and water entering the bearings. This is even more so a problem if the frame features a cut out on the bottom bracket lug. So why not just run the cables above the dust sleeve than? Well, that's already half the answer to the problem. But, since most dust sleeves are made of thin, flexible plastic, they wouldn't withstand the tension of the gear cables and soon give in.
At this point, Chesini came up with a brilliant and beautiful, yet simple, solution. They turned an aluminium sleeve to perfectly fit in between the bottom bracket cups. The sleeve features elegant cable guiding grooves on the outer circumference, wide enough to allow for not only the radial guidance, but also the slight lateral guidance, which is needed for the rear derailleur.
Unfortunately, they may have been lost over the years, or a frame may have been purchased second-hand without the sleeve. This is a pity for many collectors, and even more so for enthusiastic riders. While replacement sleeves are rare and hard to find, they don't have to be — at least not anymore! Here at Velosaloon, we took matters into our own hands and created a technical drawing based on an original spare sleeve from our storage. We then contacted a local metal craftsman and bike enthusiast with over 20 years' experience of professionally turning parts by hand — this is where the magic happened! In his workshop in the heart of Vienna's sixth district, he perfectly recreated the Chesini Aero bottom bracket gear cable guide sleeves!
It is now available to purchase on our website. This solution may not be exclusive to Chesini Aero frames — please check your Aero frame or send us a picture to verify. Just as with the original sleeve, this one is designed to fit Italian threaded Campagnolo bottom brackets, but it should also fit any bottom brackets, which share the same cup dimensions as the classic Campagnolo C-Record, Super Record or Nuovo Record bottom brackets.
Many of the artisan vintage steel frames that we love and adore so much, especially those from the 1980s, had internally routed brake and gear cables. This design offered aerodynamic benefits as well as a sleek look. Chesini was one of the manufacturers who understood the art of internal cable routing to perfection. Both the prestigious X-Uno and the Precision 83 featured aero-guided cables.
While it does really look good, to enter the cables through the downtube - right where the levers are - and just let them exit - right where the derailleurs sit - this also brings up a difficulty of, how to run the cables along the bottom bracket?
For precise shifting, gear cables need to move smoothly with low friction and without a narrow radius. While one might think that the cable could simply run along the bottom bracket axle — the radius is large enough, and steel-on-steel friction is low enough — this would in fact be a fatal idea. As both parts move — especially the axle, which turns constantly when pedalling — they would soon start to abrade each other to the point where either the cable would tear or, even worse, the axle would break in half. Furthermore, it would not be possible to cover the bottom bracket in a dust sleeve, meaning you would lose protection against dirt and water entering the bearings. This is even more so a problem if the frame features a cut out on the bottom bracket lug. So why not just run the cables above the dust sleeve than? Well, that's already half the answer to the problem. But, since most dust sleeves are made of thin, flexible plastic, they wouldn't withstand the tension of the gear cables and soon give in.
At this point, Chesini came up with a brilliant and beautiful, yet simple, solution. They turned an aluminium sleeve to perfectly fit in between the bottom bracket cups. The sleeve features elegant cable guiding grooves on the outer circumference, wide enough to allow for not only the radial guidance, but also the slight lateral guidance, which is needed for the rear derailleur.
Unfortunately, they may have been lost over the years, or a frame may have been purchased second-hand without the sleeve. This is a pity for many collectors, and even more so for enthusiastic riders. While replacement sleeves are rare and hard to find, they don't have to be — at least not anymore! Here at Velosaloon, we took matters into our own hands and created a technical drawing based on an original spare sleeve from our storage. We then contacted a local metal craftsman and bike enthusiast with over 20 years' experience of professionally turning parts by hand — this is where the magic happened! In his workshop in the heart of Vienna's sixth district, he perfectly recreated the Chesini Aero bottom bracket gear cable guide sleeves!
It is now available to purchase on our website. This solution may not be exclusive to Chesini Aero frames — please check your Aero frame or send us a picture to verify. Just as with the original sleeve, this one is designed to fit Italian threaded Campagnolo bottom brackets, but it should also fit any bottom brackets, which share the same cup dimensions as the classic Campagnolo C-Record, Super Record or Nuovo Record bottom brackets.
