Bending my first seatstays

I bought a cheap bender made out of oak from a guy back east named Nicolai or something.  He was advertising them on frameforum as a cheap alternative to the more expensive benders (which are insanely expensive but most small guys make their own it seems) and something good to learn on.  I have no idea where I’d get the tools or wood to make my own, at least very well, so I laid down the $70 for the bender.  It’s supposed to mainly be a road/cx fork blade bender, but he said it could be used for thinner tubes up to 5/8″ diameter.  I want to use it for seatstays and maybe even small diameter double top tubes like on old cruisers or Retro-Tec style frames.  The thing is small, and the first 16mm x 0.035″ tubing I put in there barely fit in the mandrel and the wood clamp broke in seconds.  Ooops.  I spent the next hour whittling a duplicate out of this block of aluminum I’ve had lying around for awhile. (I knew I’d use it someday!)

You can see the funny piece of AL on the wood mandrel in the vise above.  It worked well but if not careful will leave dents on the tube – unlike what the wood would do, so it’s not ideal but it does bend the tube and does it really well! It’s SO simple to use.  It’ll definitely take practice to get the right amount of bend in the right places, but even my first tubes turned out alright!

I really like unicrown/wishbone seatstays like Dekerf/Sycip/Hunter but for this touring bike I wanted to try out ‘regular’ stays, but with a little bit different style.  More bend at the top that meets almost in a unicrown style union at the seatstay.

These look like they have a really wide berth around the tire, which they kind of do, but it’s somehow exaggerated in that photo.  I wasn’t even going to use these stays since they’re just straight gauge 4130 (heavier) but they turned out ok! I even (accidentally) put a little bit of a ‘sag’ in them so to offer some a more flex ride back there. (Think the original Ritchey cross frames, or Willits seatstays which are both to the extreme but the same idea.) I may just use them as practice to miter the fishmouth’s at the seat tube since those are a total bitch to get right, but we’ll see…maybe they’ll be on the bike when it goes to welding.

The 2nd frame is coming along nicely.  The chainstays turned out pretty good compared to last time.  I ended up having to shorten the chainstays about 3mm due to a mitering ‘issue’ but that’s ok since they’re super long in the first place.  The Paragon dropouts I’m using turned out to be a long bigger and longer than I had realized and didn’t put the right numbers into BikeCAD.  But it’s always easier to go shorter than longer so it was no biggie. Now the chainstays are only 467mm (18.4″) instead of 470 (18.5″)!  hah…

One Response

  1. Nicely done!

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