Roy's Groovy mod...

Gonna make this a quick post, as I'm really trying to get as much forward momentum in the shop as possible right now...the show draws near (yikes!)

One of the projects that has been in the shop awaiting some work is Roy's polka dot bike that I built back about 3 years ago.  This was originally built up with Magura Firm Tech brakes, 26" Rohloff wheels, and an old school bar stem combo. 

As this was the first frame built with the Firmtechs in the US, there was very little info available as to design, fabrication, performance, anticipated braking forces, etc...  At the time of the build spec, I tried to encourage Roy to go with Discs, as the experience would be worlds apart from his old school cantis... no dice.  So, long story short, the bike is back for some work; on the agenda is the removal of the Firm tech mounts, the addition of disc brakes, and a new disc friendly fork. 

Part way into the work, I realized that all things being equal, the bike could be significantly improved on.  I did not like the fatigue the Firmtechs placed on the stays over the last three years, determined a fixed dropout system would be cleaner, rationalized that Roy is a big guy on some little wheels, etc...Why not bring it up to date?

So some quick emails later, we had a plan. 

After some quick calculations, I determined the bike could be built back as a 650b with almost no perceptible change in the geometry, the calipers indicating the necessary increase in axle to crown...

The new wheel size and rigid fork would change up the angles only about a 1/2 degree...easily corrected to achieve the same trail as before, but with a larger surface contact patch, greater momentum, and roll over capability.

Emboldened with the new direction, I lopped off the rear end. "Eeegad, you did what?"  Yep, decided it would be quicker to just start fresh out of the gate. 

So long to put together,so little time to hack apart...

 

A view of the vent holes in the bottom bracket, placed high on the tube to allow the argon to push the oxygen out during purging if desired.

After some meticulous work with the 4.5" grinder, Dotco file, and finally hand files, she's smooth and ready to go...

I've got to get to fabricating a Rohloff compatible dropout, cutting up a new rear end, and who knows, may even have another surprise for Roy too ;)

While the paint on the frame was bubbling off, I ended the evening finishing off  a few more Ti bars...

Never alone in the shop, Frankie likes to sleep right under my feet while welding.  Comforting, but a bit of a problem when he gets up and steps on the pedal :)

 Catch y'all tomorrow,

rody