NP Yggdrasil - but I'd suggest not waiting for me to get one o'these lol;
...as at this point I'm not entirely sure what I'm gonna do, Mongo has turned out so well that the "just a quick test of the ehub" phase has turned into at least two months of constant use so far & I'm kinda tempted to leave it as is & just get another hub for the taddy & another bike for a winter beater - then again if I do that I'll prolly just get another Mongoose Snarl so... erm... yea, I dunno heh
Anyway, I did a quick "test fit" with one of the in-frame kit two smokers by just holding one in there (w/o carb & exhaust) & it seems to have the room, close enough to work with anyway & for the oversized down tube mount I was thinkin' about fabricating something similar to the SBP
"large universal front mount";
With an over sized U bolt & steel "pads" (1/2 chunks of pipe) to help diffuse the crush load/crimping force (pics are frm my Rollfast);
...the Mongoose's D tube isn't perfectly round/symmetrical in cross section, so a U bolt clamp may have to be fabricated/modified specifically for it, but that's not a particularly difficult task *shrug*
Good luck & remember to keep us posted!