So I built my own 69er early this year with a 2007 BMC Trailfox 01 frame and all the parts from Jenson and Price Point. My calculations for this build was based on the Trailfox frame normally takes a 130mm fork with a 26" wheel.
So The 29er Reba SL fork set at 100mm(max) + 29" wheel(1.5" increase = 36mm) = 136mm. So my 29er fork and 29" wheel setup would work fine since it wouldn't slacken the steep 71 degree HA.
Well all has been fine until I recently upgraded to 175mm SLX crank from a 170mm cheapo. (175mm is def the crank I need) Now that extra 5mm is causing just the slightest toe rub for me when i turn the wheel and my foot/pedal is cranking.
So what to do?
1) Don't want to go lower on the crank. perhaps a smaller tire? It's currently maxis ignitor 29 X 2.1. and a 26 X 2.1 in the rear.
2) my spd cleats are already set as far forward as possible in my shoe....Perhaps something I can add to the headset to slacked the Head tube angle just a wee bit?
3) Finally was considering buying a new 29er fork at 130mm or greater. I wouldn't mind the slacken Head angle at this point. Would the extra 30mm raise the bike high enough to offset this toe rub? I'm considering this because in case the wheel rub is still happening, I can just buy a 26" or 650B wheel, and I'll be back to the original fork/spec recommendations. And then I can use the original 29" wheel and 100mm 29er fork for my next 29er full build in the future. But if I'm told this extra 30mm won't even help, then I'll just scrap this idea too
Note to others - be weary of 71 degree head angles, when adding a 29 to a 26 frame - you'll prob have the same issues as me