Friday, February 18, 2011

snippets and stuff...

Toiling away.

I am pleased that Roy's 650b conversion came out as hoped/anticipated.  It's one thing to calculate it out on paper, see that it is possible, and make the decision to move forward, another altogether to put the angle finders and tape to the finished fabrication and see just how close we came.  Nailed it.

Old stats...                            New stats...

Head angle   71                     71
Seat angle     72                    72
Wheel base  42.00"               42.25"
Trail             72mm               70mm

The bike should still be flikably quick but now offer better rollover capability and momentum with the larger contact patch.  The only compromise was the rear chainstay spacing; as I was working off of an existing bottom bracket and had specific design parameters/restrictions for the Rohloff and Hot Rods, I was able to fit a 2.5" tire in, but with only about .25" lateral to either side.  The use of oval stays helped, but with Roy's size, I could not in good conscious dimple them on the interior aspect to cheat a bit more space, they would have succumbed to cyclic fatigue earlier.

A shot of the stay brazing after soaking...I fed the silver a good .625" into the stays to really support the anticipated stresses.
A look at the one piece bar/stem combo for the build...built out with a 28" bar, it will allow a bit more leverage against the larger contact patch tire to keep steering an unconscious effort.

Lots entering the paint booth today; three frames, three forks, bars and some stems.

I've got two more ti stems to work on as well, hoping to find an extra ounce of energy somewhere the next few days :)



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