Something to keep in perspective, here, is the fact that as RC-type motors go, one with an 80mm diameter, 40mm long stator, is huge. After thinking about it some more, I'm convinced this version will definitely have plenty of power, even for a motorcycle setup. It won't be taxed in any ebike application we've been discussing here. I base this on my observed experiences with Steve Neu's motors. The most powerful RC motor I've every played with is his 2230, which has been installed on 40% models that hit 15kW peaks. This motor is 4-poled, with 12 slots, has a stator diameter of 2.2" and a stator length of 3.0". In metric terms, that is approximately 56m x 76mm. This motor design is basically just a larger version of his popular 4-poled 1500 series, which have 1.5" diameter stators. The 1500s are very efficient, and can be spun as high as 100,000 rpm, continuously. To get lots of torque out of them, however, you need to gear them down. Outrunners became popular because you coud get high torque at much lower rpm. They typically have 8, or more, poles, have larger diameters and shorter lengths.
Steve then did his 1900 OutRunner Killer, or "ORK" series. These had larger 1.9" diameter stators that were quite a bit shorter. What I found is that a 1910, which has a stator length of 1.0", had pretty much as much torque in a helicopter as the 1515 (1.5" long stator...) did geared down 2:1. Because these 1900s ran so much more efficiently than most every outrunner I tried in the same size range, these quickly became the motors of choice for high-power helicopter setups. Gobs of power, and very little heat, even running them as high as 30,000 rpm.
I think we can make a similar comparison to David's 8-poled, 24-slot, 8040, and Steve Neu's 4-poled, 12-slot 2230. The 8040 should at least equal the performance of 2230, but I think it will do better. Anyway, my point to all this is that we don't really need to worry about over-gearing, or maximizing efficiencies with this beast. I just don't think it won't break a sweat for any of the setups I've seen proposed here.
-- Gary