Tuesday, January 31, 2012

Building a mountain bike Coconino Style #3.

Onwards! Here, you have your seat stays. You either buy them bent or bend them yourself, but bending is another one of those skill sets that is constantly evolving build to build and stay to stay, and has allot of "feel" and the best thing to do is just dive in and start bending.
You can see the sharpie marks? those are the apex of the bends.

Vent holes have been drilled on the seat tube and on the lower ends of the seat stays, the same as with the chain stays in post #2.

Again, they are mounted in an Anvil fixture for mitering, and are mitered simultaneously.

The stays are then finish fitted at the top, mostly just burr removal, and the marked for slotting, spear pointed and the insides and outsides of the ends cleaned 1st with 80 grit and a dremmel, and then with 91% alcohol, again - much like the chain stays in post #2.

I do one to perfect fit, and then match the 2nd to it.

And, once both stays are on it's back to the alignment table for a check. Usually at this point the frame has enough different triangles that it does not tend to move or wander.

It's good to get it all sussed up at this point as once you install the seat stay brace the entire structure is all tied together.

Plus, it's nice to throw in the test wheel once again to check clearances and find out exactly where you want your brace to go.

the brace is tacked in in the jig with an appropriate dummy axle to prevent the stays from pulling in, and then I check the dropouts one last time before I braze the entire frame at once.

All brazed up! Ready for de-fluxing, polishing and braze ons as well as one last alignment check and off to the painter it goes.

finished brazing. I hope this has helped out!

- Steve Garro.


Anonymous said...

My name is Scott. I came to your shop with Chauncey Matthews several years ago. I follow your stuff. This was a really cool process. Sweet bikes. Take care.

Anonymous said...

Mmm - J-lo seat stays work for me!

Informative as always.....one question; what's the wall thickness on the two 4130's going into those stays? Cheers

Peter (England)

steve garro said...

^^^^ Sorry, trade secret! ^^^^
It can also vary bike-to-bike......
- Steve.

Anonymous said...

I've been following your builds for years. You make beautiful raw fillets. Unfortunately, I just can't appreciate the fine details on the small size photos you've been using lately. Any chance you could go back to the higher resolutions photos?


steel is real said...

excuse me.
What kind of % brass do you use?
can I ask?.

steve garro said...

I use Aufhauser's 680 with nickle for brass brazing/bronze welding - sorry about the small-res pics, but I'm hosting several thousands of them and they are easier to e-mail and such.......stop by and see some in person!