Abe’s 29 plus or minus

Abe and I met about 5 years ago at the local bike shop where i was displaying my bikepacking rig as Isaac was giving a talk on the art of bikepacking.  I remember Abe talking about wanting a custom bike some day and that if he were to pull the trigger it would be for a gearbox build for its practicality in touring – very little maintenance and virtually bombproof.  Fast forward 5 years and that’s not at all what we made.  Since then he has been riding a Salsa Woodsmoke that has treated him well but like all carbon frames there is a little bit of trepidation when he is out on a long bike tour in such places as Baja California.  For example how the head tube has no metal inserts for the integrated bearings to sit upon which may be ok but not confidence inspiring. How if the frame breaks your tour is done. With steel you can bend or get it repaired almost anywhere in the world.  Yes that does happen and it’s a real thing!  He knew he was going way up in frame weight but he wanted something that rode like the Woodsmoke but in steel. He wanted the super short chainstays and as big a front triangle for storage, lots of bosses for a bolt on bag and bottle attachments, as well as the well-loved but rarely used portage handle. He chose Paragon Rocker dropouts for wheelbase/chainstay/tire size adjustability; a tapered head tube mostly for that integrated look with the fork crown; water bottle bosses on the lower seatstays that would house a tall thermos and avoid the legs on a small puffy-stuff rack that would carry maybe 5lbs of stuff (in lieu of a saddle bag that sways up high and isn’t great with a dropper post). The rack has high/low mounts so it can be as close to the tire size he chooses whether it’s 29×2.3 or 29×2.8, though likely never over a 2.6 he says. The rest was up to me on how to connect the dots.  I built the bike with different geometry than the Woodsmoke but with the fit he has come to love on his old bike. It’s slacker and longer – more Forward Geometry – and more fun and confidence inspiring.

I asked a friend involved in the Trek Stache+ design for advice. I had been shown an early metal prototype of that frame so that’s what i was going off with where this build was going. He said that they kept “throwing material at it” (the frame) to make it strong and stiff enough since an elevated driveside chainstay introduces potential for lots of new stress risers in places double-triangle frames don’t have (like the middle of the seat tube), and introduces lateral flex of the rear triangle and rear wheel from the dropout being cantilevered out there – especially with low-mount dropouts like the Rockers.  As far as I know, Doug Bradbury made the first known MTB of this design way back in the 90’s sometime as a Manitou (see below photo). The benefit is pretty obvious: you get rid of the pinch point of the tire/chainrings/chainstay so you can run shorter chainstays with a bigger chainring/s. Back then i think it was more about getting rid of chain-suck (we were using 3x’s) and chainslap while not going full elevated chainstay which was found to be flexier and weaker. This was a middle ground of adding more frame strength, less flex and similar same ride characteristics of a double-triangle frame. I’m not sure why it didn’t catch on until decades later…