Caletti Cycles


process - fabrication 3 fabrication pages: p1 p2 Seatstays Many bikes use S-bend style seatstays. I made a cool tool to bend stays for single or double bends. It's very helpful for getting the right amount of clearance on particulary big or small frames, or for cross bikes. Basically it gives me more design freedom and makes a very sexy bend! The bender is made from delrin, machined on the mill using a rotary table, the roller is made of several parts that were turned on the lathe, the base is welded and machined steel with a 2 piece brass bushing pivot made on the lathe. There are numbered holes for a dowel pin stop so bends can be measured and repeated. Groovy! Many thanks to Don Ferris at Anvil Bikeworks for his input on designing this tool!
The roller and mandrel fit the tube very well so it is fully supported for a smooth bend.
The solid and adjustable stops are used to measure the stays to assure symmetry.
Here I'm setting up a seatstay in the fixture for mitering. I have already mitered the dropout end, this is the end that will join the seat tube. I have a dummy seat tube to help plan the cut.
Here the stay has been mitered on the mill, the other stay will go in and get mitered as well. The seat stay fixture is mounted on an adjustable angle vise. In this picture it's all sitting in the bench vise, but the mitering happens on the milling machine.

Here I'm checking the miters and will make adjustments to get it to fit just right. When fitup is correct the stays get tacked and welded on. Next a brake bridge (road) or seat stay bridge is made and brazed in, like the chainstay bridge. The seat tube will get slotted, and final rear end braze ons installed, alignment checked and adjusted as needed, and it's packed and sent to Spectrum for powdercoating.
When the frame comes back from powdercoat it gets it's final preparation done. This includes aligning the rear derailleur hanger, cleaning the threads of the bottle cage bosses, Reaming and facing the head tube, facing the BB, chasing the BB threads. After this it is ready to be assembled with the parts into a beautiful complete bicycle, and get ridden!
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